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  • Calculation of Milestones/Task list

    - by sugar
    My project manager assigned me a task to estimate the development time for an iPad application. Lets assume that I gave estimation of 15 working days. He thought that the number of days where too many and client needed the changes to the application urgently (as in most of cases). So, he told me: "I am going to assign two developer including you and as per my understandings and experience it won't take more than seven working days." Clarifications I was given the task of estimating development time for an individual. How could I be sure that 2 developers are going to finish it within 7 days? (I am new to team & I hardly know the others abilities) Questions Why do most of project managers / team leaders have understandings like: If one developer requires N days, Then two developers would require N/2 days, Do they think something like developer = s/w production machines? Should a team member (developer, not team lead or any higher post) estimate other developers work? I didn't deny anything in the meeting and didn't said, but what should be the appropriate answer to convince them that N/2 formula that they follow is not correct?

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  • Looking to create website that can have custom GUI and database per user

    - by riley3131
    I have developed an MS Access database for a company to track data in regards to production of a certain commodity. It has many many tables, forms, reports, etc. These were all done as the user requested, and resemble the users previously used system, mostly printed worksheets and excel workbooks. This has created a central location for all information and has allowed the company to compare data in a new way. I am now looking to do this for other companies, but would like to switch it to a web application. Here is my question. What is the best way to create unique solutions for individual companies that can have around 100 users each? I would love to create one site that would serve all parties, but that would ruin the customizable nature of what I am developing. I love the ability to create reports, excel sheets, pdf, graphs, etc with access, but am tired of relying on my customers software, servers, etc. I have some experience with WAMP, but I am far better at VBA. I was okay at PHP, and was getting a grasp on JavaScript a few years back. I am also trying to decide whether to go with WAMP or LAMP, if web is the best choice. Also, should I try set up one site for all users that after log-in goes to company specific pages, or individual sites for each company? Should I host or use a service?

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  • How can I make my PHP development environment more efficient?

    - by pixel
    I want to start a home-brew pet project in PHP. I've spent some time in my life developing in PHP and I've always felt it was hard to organize the development environment efficiently. In my previous PHP work, I've used a windows desktop machine and a linux server for development. This configuration had it's advantages: it's easy to configure Apache (and it's modules)/PHP/MySql on a linux box, and, at the time, this configuration was the same like on production server. However, I never successfully set up a debug connection between my Eclipse install and X-debug on server. Transferring files from my local workspace to the server was also very annoying (either ftp or Bazaar script moving files from repository to web root). For my new setup, I'm considering installing everything on my local machine. I'm afraid that it will slow down workstation performance (LAMP + Eclipse), and that compatibility problems will kick-in. What would you recommend? Should I develop using two separate machines? On one? Do you have experience using one of above configurations in your work?

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  • Need a Quick Sure Method to Produce a Formatted Explain Plan? This will help!

    - by user702295
    Please use the following on the production machine to get formatted explain plan and sql trace using the SLOW sql (e.g. 'T_COMB_LIST.COMB_ID = 216') or any other value that takes longer: -- Open new session is SQL*Plus */ -- Make sure you are using updated PLAN_TABLE -- This can be done by dropping it and recreate it by running: -- SQL> @?/rdbms/admin/utlxplan.sql) set lines 1000 set pages 1000 spool xplan_1.txt EXPLAIN PLAN FOR <<<<Replace this line with exactly the same query you used above. Force hard parse by modifying the case of a character>>>> @?/rdbms/admin/utlxplp spool off EXIT --Open a second session is SQL*Plus ALTER SESSION SET max_dump_file_size = unlimited; ALTER SESSION SET tracefile_identifier = '10046'; ALTER SESSION SET statistics_level = ALL; ALTER SESSION SET events '10046 trace name context forever, level 12'; <<<<Replace this line with exactly the same query you used above. Force hard parse by modifying the case of a character>>>> select 'verify cursor closed' from dual; ALTER SYSTEM SET EVENTS '10046 trace name context off'; EXIT Make sure spooled file is formatted properly and that the 10046 trace has relevant explain plan in it.  Please Upload both files (10046 trace is generated in udump). Need instructions to find udump?   sqlplus "/ as sysdba" show parameters dump_dest This will show you bdump, cdump and udump locations.

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  • I can't see how a mature agile team requires any *management*?

    - by ashy_32bit
    After a recent heated debate over Scrum, I realized my problem is that I think of management as a quite unnecessary and redundant activity in a fully agile team. I believe a mature Agile team does not require management or any non-technical decision making process of whatsoever. To my (apparently erring) eyes it is more than obvious that the only one suitable and capable of managing a mature development team is their coach (and that being the most technically competent colleague with proper communication skills). I can't imagine how a Scrum master can contribute to such a team. I am having a great difficulty realizing and understanding the value of such things as Scrum and manager as someone who is not a veteran developer but is well skilled in planning the production cycles when a coach exists in the team. What does that even mean? How on earth someone with no edge-skills of development can manage a highly technical team? Perhaps management here means something else? I see management as a total waste of time and a by-product of immaturity. In my understanding a mature team is fully self-managing. Apparently I'm mistaken since many great people say the contrary but I can't convince myself.

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  • Enablement 2.0 Get Specialized

    - by mseika
    Oracle PartnerNetwork Specialized program is releasing new certifications on our latest products, and partners are invited to be the first candidates.Oracle Taleo Enterprise Cloud Service 2013 Specialization – Now Active!This specialization recognizes partner organizations that are proficient in positioning, selling and implementing Taleo’s Enterprise Talent Management solutions.Taleo's Talent Management Cloud helps organizations attract, develop, motivate and retain human capital to improve performance and drive growth. Oracle’s Taleo Enterprise Cloud Service 2013 Specialization encompasses the following products: Oracle Taleo Performance Management Cloud Service, Oracle Taleo Recruiting Cloud Service and Oracle Taleo Performance Management Cloud Service.Topics covered in this Specialization include: Selling and positioning Taleo’s Talent Management Cloud; Functional and Technical positioning. Implementation tracks are included for Taleo Performance Management Cloud Service, Oracle Taleo Recruiting Cloud Service and Oracle Taleo Performance Management Cloud Service. Oracle partners who achieve this Specialization are differentiated in the marketplace through proven expertise in Oracle Taleo Enterprise Cloud Service.New Certified Implementation Specialist Exam in Production! Oracle Taleo Recruiting Cloud Service 2013 Certified Implementation Specialist (1Z0-474) All Beta exam participants will receive their exam scores as of beginning of July 2013. The successful candidates will receive their certificates starting mid-July 2013. Take the exam now at a near-by Pearson VUE testing center!Contact Us Please direct any inquiries you may have to Oracle Partner Enablement team at [email protected].

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  • Enablement 2.0 Get Specialized

    - by mseika
    Oracle PartnerNetwork Specialized program is releasing new certifications on our latest products, and partners are invited to be the first candidates.Oracle Taleo Enterprise Cloud Service 2013 Specialization – Now Active!This specialization recognizes partner organizations that are proficient in positioning, selling and implementing Taleo’s Enterprise Talent Management solutions.Taleo's Talent Management Cloud helps organizations attract, develop, motivate and retain human capital to improve performance and drive growth. Oracle’s Taleo Enterprise Cloud Service 2013 Specialization encompasses the following products: Oracle Taleo Performance Management Cloud Service, Oracle Taleo Recruiting Cloud Service and Oracle Taleo Performance Management Cloud Service.Topics covered in this Specialization include: Selling and positioning Taleo’s Talent Management Cloud; Functional and Technical positioning. Implementation tracks are included for Taleo Performance Management Cloud Service, Oracle Taleo Recruiting Cloud Service and Oracle Taleo Performance Management Cloud Service.Oracle partners who achieve this Specialization are differentiated in the marketplace through proven expertise in Oracle Taleo Enterprise Cloud Service.  New Certified Implementation Specialist Exam in Production! Oracle Taleo Recruiting Cloud Service 2013 Certified Implementation Specialist (1Z0-474) All Beta exam participants will receive their exam scores as of beginning of July 2013. The successful candidates will receive their certificates starting mid-July 2013.   Take the exam now at a near-by Pearson VUE testing center!Contact Us Please direct any inquiries you may have to Oracle Partner Enablement team at [email protected].

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  • Enablement 2.0 Get Specialized

    - by mseika
    Oracle PartnerNetwork Specialized program is releasing new certifications on our latest products, and partners are invited to be the first candidates.Oracle Taleo Enterprise Cloud Service 2013 Specialization – Now Active!This specialization recognizes partner organizations that are proficient in positioning, selling and implementing Taleo’s Enterprise Talent Management solutions.Taleo's Talent Management Cloud helps organizations attract, develop, motivate and retain human capital to improve performance and drive growth. Oracle’s Taleo Enterprise Cloud Service 2013 Specialization encompasses the following products: Oracle Taleo Performance Management Cloud Service, Oracle Taleo Recruiting Cloud Service and Oracle Taleo Performance Management Cloud Service.Topics covered in this Specialization include: Selling and positioning Taleo’s Talent Management Cloud; Functional and Technical positioning. Implementation tracks are included for Taleo Performance Management Cloud Service, Oracle Taleo Recruiting Cloud Service and Oracle Taleo Performance Management Cloud Service. Oracle partners who achieve this Specialization are differentiated in the marketplace through proven expertise in Oracle Taleo Enterprise Cloud Service.New Certified Implementation Specialist Exam in Production! Oracle Taleo Recruiting Cloud Service 2013 Certified Implementation Specialist (1Z0-474) All Beta exam participants will receive their exam scores as of beginning of July 2013. The successful candidates will receive their certificates starting mid-July 2013. Take the exam now at a near-by Pearson VUE testing center!Contact Us Please direct any inquiries you may have to Oracle Partner Enablement team at [email protected].

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  • Enablement 2.0 Get Specialized

    - by mseika
    Oracle PartnerNetwork Specialized program is releasing new certifications on our latest products, and partners are invited to be the first candidates.Oracle Taleo Enterprise Cloud Service 2013 Specialization – Now Active!This specialization recognizes partner organizations that are proficient in positioning, selling and implementing Taleo’s Enterprise Talent Management solutions.Taleo's Talent Management Cloud helps organizations attract, develop, motivate and retain human capital to improve performance and drive growth. Oracle’s Taleo Enterprise Cloud Service 2013 Specialization encompasses the following products: Oracle Taleo Performance Management Cloud Service, Oracle Taleo Recruiting Cloud Service and Oracle Taleo Performance Management Cloud Service. Topics covered in this Specialization include: Selling and positioning Taleo’s Talent Management Cloud; Functional and Technical positioning. Implementation tracks are included for Taleo Performance Management Cloud Service, Oracle Taleo Recruiting Cloud Service and Oracle Taleo Performance Management Cloud Service.Oracle partners who achieve this Specialization are differentiated in the marketplace through proven expertise in Oracle Taleo Enterprise Cloud Service.New Certified Implementation Specialist Exam in Production! Oracle Taleo Recruiting Cloud Service 2013 Certified Implementation Specialist (1Z0-474) All Beta exam participants will receive their exam scores as of beginning of July 2013. The successful candidates will receive their certificates starting mid-July 2013. Take the exam now at a near-by Pearson VUE testing center!Contact Us Please direct any inquiries you may have to Oracle Partner Enablement team at [email protected].

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  • A Myriad of Options

    - by Mark Hesse
    I am currently working with a customer that is close to outgrowing their Exadata X2-2 half rack in both compute and storage capacity.  The platform is used for one of their larger data warehouse applications and the move to Exadata almost two years ago has been a resounding success, forcing them to grow the platform sooner than anticipated. At a recent planning meeting, we started looking at the options for expansion and have developed five alternatives, all of which meet or exceed their growth requirements, yet have different pros and cons in terms of the impact to their production and test environments. The options include an in-rack upgrade to a full rack of Exadata using the recently released X3-2 platform (an option that even applies to an older V2 rack), multi-rack cabling the existing X2-2 to another full rack or half rack X2-2 (and utilizing both compute and storage capacity in the other rack), or simply adding a new X3-2 half rack (and taking advantage of the added compute and flash performance in the X3-2). While the decision is yet to be made, it had me thinking that one of the benefits of Exadata over a traditional database deployment is that when the time comes to expand the platform, there are a myriad of options.

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  • How can I make my PHP development environment more efficient?

    - by pixel
    I want to start a home-brew pet project in PHP. I've spent some time in my life developing in PHP and I've always felt it was hard to organize the development environment efficiently. In my previous PHP work, I've used a windows desktop machine and a linux server for development. This configuration had it's advantages: it's easy to configure Apache (and it's modules)/PHP/MySql on a linux box, and, at the time, this configuration was the same like on production server. However, I never successfully set up a debug connection between my Eclipse install and X-debug on server. Transferring files from my local workspace to the server was also very annoying (either ftp or Bazaar script moving files from repository to web root). For my new setup, I'm considering installing everything on my local machine. I'm afraid that it will slow down workstation performance (LAMP + Eclipse), and that compatibility problems will kick-in. What would you recommend? Should I develop using two separate machines? On one? Do you have experience using one of above configurations in your work?

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  • Do you have to recreate workspaces after upgrading a TFS 2008 server to TFS 2010?

    - by Clara Oscura
    I am just reposting this thread from a MSDN forum since it seems to be unavailable. It was very useful when I was having trouble with my folder mappings after migrating to TFS 2010. Question: I opened VS2008 and connected it to the upgraded 2010 TFS server.  Upon clicking any of our Team Projects in source control explorer I get "Team Foundation Error - The workspace MYWORKSPACE;DOMAIN\MYUsername already exists on computer MYPCNAME." Answer: The same local paths on your machine are mapped to 2 different workspaces, one on the preupgrade server and one on the postupgrade server.  It's not safe to have multiple workspaces on different servers mapped to the same local paths b/c you could pend some changes while connected to one server, and the other server would have no idea what you did.  You should either delete your conflicting workspaces from one of the servers (if you don't need them on both), or test the new TFS instance from a new workspace (on different machine). If you want to test an existing production workspace on both servers, then yes, you will have to mess around with the workspace cache. You don’t have to delete the entire cache, you just need to run "tf workspaces /remove:* /server:<serverurl>" to clear the cached workspaces from a server (the command won't delete the workspaces), and possibly "tf workspaces /server:<server>" to refresh the workspace cache for a given server.  You will also have to do back up and restore the workspace before switching servers or your local files could be inconsistent. From the “Microsoft Visual Studio Team Foundation Server 2010 Beta 1” forum (not available anymore?) Technorati Tags: TFS 2010,TFS Workspaces,Team System,Team Foundation Server 2010

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  • MySQL Connector/NET 6.9.1 beta has been release

    - by Roberto Garcia
    Dear MySQL users, MySQL Connector/Net 6.9.1 a new version of the all-managed .NET driver for MySQL has been released. This is a beta release for 6.9.x and is not recommended for production environments. It is appropriate for use with MySQL server versions 5.5-5.7. It is now available in source and binary form from http://dev.mysql.com/downloads/connector/net/#downloadsandmirrorsites (note that not all mirror sites may be up to date at this point-if you can't find this version on some mirror, please try again later or choose another download site.) Changes in MySQL Connector/Net 6.9.1 (2014-05-29, Beta)    Functionality Added or Changed      * Asynchronous methods are now supported.    Bugs Fixed      * When a client refreshed a web page associated with an expired        session and if the ASP.NET project was using <SessionState ...        regenerateExpiredSessionId="true" ...>, a "duplicate entry"        exception was generated from the MySqlSessionProvider. (Bug        #18657550, Bug #70409) The documentation is available at: http://dev.mysql.com/doc/refman/5.7/en/connector-net.html Enjoy and thanks for the support! On behalf of the MySQL Connector/NET and the MySQL/ORACLE RE Team. 

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  • maxItemsInObjectGraph limit required to be changed for server and client

    - by Michael Freidgeim
    We have a wcf service, that expects to return a huge XML data. It worked ok in testing, but in production it failed with error  "Maximum number of items that can be serialized or deserialized in an object graph is '65536'. Change the object graph or increase the MaxItemsInObjectGraph quota."The MSDN article about   dataContractSerializer xml configuration  element  correctly  describes maxItemsInObjectGraph attribute default as 65536, but documentation for of the DataContractSerializer.MaxItemsInObjectGraph property and DataContractJsonSerializer.MaxItemsInObjectGraph Property are talking about Int32.MaxValue, which causes confusion, in particular because Google shows properties articles before configuration articles.When we changed the value in WCF service configuration, it didn't help, because the similar change must be ALSO done on client.There are similar posts:http://stackoverflow.com/questions/6298209/how-to-fix-maxitemsinobjectgraph-error/6298356#6298356You need to set the MaxItemsInObjectGraph on the dataContractSerializer using a behavior on both the client and service. See  for an example.http://devlicio.us/blogs/derik_whittaker/archive/2010/05/04/setting-maxitemsinobjectgraph-for-wcf-there-has-to-be-a-better-way.aspxhttp://stackoverflow.com/questions/2325321/maxitemsinobjectgraph-ignored/4455209#4455209 I had forgot to place this setting in my client app.config file.http://stackoverflow.com/questions/9191167/maximum-number-of-items-that-can-be-serialized-or-deserialized-in-an-object-graphttp://stackoverflow.com/questions/5867304/datacontractjsonserializer-and-maxitemsinobjectgraph?rq=1 -It seems that DataContractJsonSerializer.MaxItemsInObjectGraph has actual default 65536, because there is no configuration for JSON serializer, but  it complains about the limit.I believe that MS should clarify the properties documentation re default limit and make more specific error messages to distinguish server side and client side errors.Note, that as a workaround it's possible to use commonBehaviors section which can be defined only in machine.config:<commonBehaviors> <behaviors> <endpointBehaviors> <dataContractSerializer maxItemsInObjectGraph="..." /> </endpointBehaviors> </behaviors></commonBehaviors>v

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  • How similiar should the environments of PreProd and Prod be?

    - by RoboShop
    I've just recently been on a project and during the release, we realized that it didn't work in Production. It works in all other environments but because we have a separate release team, and we cannot set up the servers and environments ourselves, we have no visibility of the configuration on them. We suspect that Prod has some user permissions in its account or IIS settings that are different, so we are working though it now. So I think this whole thing has been a learning experience for me and I don't want the same thing repeated again. I would like to ask, how different should these environments be? I always thought that PreProd should be an identical copy to the Prod environment using a copy of the same database, using a copy of the same user account, should be installed on the same servers etc. But how far should I take it? If the web site is externally facing, should PreProd be externally facing? What if the website has components that don't require a user account or password to navigate to? Is it still okay to expose it to the outside world?

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  • Scala - learning by doing

    - by wrecked
    coming from the PHP-framework symfony (with Apache/MySQL) I would like to dive into the Scala programming language. I already followed a few tutorials and had a look at Lift and Play. Java isn't a stranger to me either. However the past showed that it's easiest to learn things by just doing them. Currently we have a little - mostly ajax-driven - application build on symfony at my company. My idea is to just build a little project similar to this one which might gets into production in the future. The app should feature: High scalability and performance a backend-server web-interface and a GUI-client There are plenty of questions arising when I think of this. First of all: Whats the best way to accomplish a easy to maintain, structured base for it? Would it be best to establish a socket based communication between pure-scala server/client and accessing that data via Lift or is building a Lift-app serving as a server and connecting the gui-client (via REST?) the better way? Furthermore I wounder which database to choose. I'm familiar with (My)SQL but feel like a fool beeing confronted with all these things like NoSQL, MongoDB and more. Thanks in advance!

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  • Server Setups for Agencies [closed]

    - by styks1987
    We are considering consolidating our server administration by cutting down on the number of systems we currently use to manage all our websites(~65 websites). Currently we have a testing server and 3 production servers. (2 - cherokee(linode), 1 - apache (mt)) We don't have a dedicated server admin, so I am stuck with managing all these servers, and as a developer, I don't want to deal with all the server hassle. So my main goal is to cut down on the time spent messing with the servers. We have looked at Pagoda Box and AppFog as possibilities. I am not sure if Pagoda Box would be cost effective. With 65+ websites we may end up paying anywhere from 0 to $50+ per website per month. Right now we page about $250 per month for the 4 VPS servers mentioned above. We already use Capistrano for deployment. I have the opportunity to completely overhaul the entire setup and I would like some feedback on where you found your information for large scale server management or how you currently do it. Articles are welcome. In summary: What is new (past 2 years) in simple server management arena? If you work at an agency or have had agency experience, how do/did you manage your sites? a. What is the level of effort for SSL, new site setup, database management, and extension management. b. How did you handle datacenter outages. Anyone with Pagoda Box experience, do you like it and did you have problems with Wordpress, Cakephp, Drupal, Expression Engine or Magento? a. Is it expensive for you? b. How has server uptime been? Your direction and comments are greatly appreciated.

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  • ???????,???????????

    - by ??-Oracle
    Normal 0 7.8 ? 0 2 false false false EN-US ZH-CN X-NONE ??: 1.???????; 2.??????????????????; 3.????????????????,??????????,????????; ??: ?????????: SQL> create table test_b (id number(10)) tablespace bbb; Table created. SQL> insert into test_b values (1); 1 row created. SQL> commit; NAME --------------------------------------------------------------------------------     FILE# ---------- /opt/oracle/oradata/R11203/aaa.dbf        10 /opt/oracle/oradata/R11203/bbb.dbf        11 11 rows selected. SQL> host ??????,?????? bash-4.2$ ls -al /opt/oracle/oradata/R11203/bbb.dbf -rw-rw----   1 oracle     dba        10493952 Apr  4 09:53 /opt/oracle/oradata/R11203/bbb.dbf bash-4.2$ mv /opt/oracle/oradata/R11203/bbb.dbf /opt/oracle/oradata/R11203/bbb.dbf.bak bash-4.2$ sqlplus / as sysdba SQL*Plus: Release 11.2.0.3.0 Production on Fri Apr 4 09:55:03 2014 Copyright (c) 1982, 2011, Oracle.  All rights reserved. Connected to: Oracle Database 11g Enterprise Edition Release 11.2.0.3.0 - 64bit Production With the Partitioning, OLAP, Data Mining and Real Application Testing options SQL> alter tablespace bbb read only; alter tablespace bbb read only * ERROR at line 1: ORA-01116: error in opening database file 11 ORA-01110: data file 11: '/opt/oracle/oradata/R11203/bbb.dbf' ORA-27041: unable to open file HPUX-ia64 Error: 2: No such file or directory Additional information: 3 SQL> shutdown immediate; ORA-01116: error in opening database file 11 ORA-01110: data file 11: '/opt/oracle/oradata/R11203/bbb.dbf' ORA-27041: unable to open file HPUX-ia64 Error: 2: No such file or directory Additional information: 3 SQL> select status from v$instance; STATUS ------------ OPEN SQL> alter system switch logfile; System altered. SQL> / System altered. SQL> / System altered. SQL>/ System altered. SQL> / System altered. SQL> / System altered. SQL> ?? SQL> shutdown immediate; ORA-01116: error in opening database file 11 ORA-01110: data file 11: '/opt/oracle/oradata/R11203/bbb.dbf' ORA-27041: unable to open file HPUX-ia64 Error: 2: No such file or directory Additional information: 3 SQL> shutdown abort; ORACLE instance shut down. ???????mount?? SQL> startup mount; ORACLE instance started. Total System Global Area  329859072 bytes Fixed Size                  2182336 bytes Variable Size             285213504 bytes Database Buffers           37748736 bytes Redo Buffers                4714496 bytes Database mounted. ??alter database create datafile <> as ....???,???????????: SQL> alter database create datafile 11; Database altered. ???????redo log????????? SQL> recover datafile 11; Media recovery complete. SQL> alter database open; Database altered. SQL> select * from test_b;        ID ----------         1 DefSemiHidden="true" DefQFormat="false" DefPriority="99" LatentStyleCount="267" UnhideWhenUsed="false" QFormat="true" Name="Normal"/ UnhideWhenUsed="false" QFormat="true" Name="heading 1"/ UnhideWhenUsed="false" QFormat="true" Name="Title"/ UnhideWhenUsed="false" QFormat="true" Name="Subtitle"/ UnhideWhenUsed="false" QFormat="true" Name="Strong"/ UnhideWhenUsed="false" QFormat="true" Name="Emphasis"/ UnhideWhenUsed="false" Name="Table Grid"/ UnhideWhenUsed="false" QFormat="true" Name="No Spacing"/ UnhideWhenUsed="false" Name="Light Shading"/ UnhideWhenUsed="false" Name="Light List"/ UnhideWhenUsed="false" Name="Light Grid"/ UnhideWhenUsed="false" Name="Medium Shading 1"/ UnhideWhenUsed="false" Name="Medium Shading 2"/ UnhideWhenUsed="false" Name="Medium List 1"/ UnhideWhenUsed="false" Name="Medium List 2"/ UnhideWhenUsed="false" Name="Medium Grid 1"/ UnhideWhenUsed="false" Name="Medium Grid 2"/ UnhideWhenUsed="false" Name="Medium Grid 3"/ UnhideWhenUsed="false" Name="Dark List"/ UnhideWhenUsed="false" Name="Colorful Shading"/ UnhideWhenUsed="false" Name="Colorful List"/ UnhideWhenUsed="false" Name="Colorful Grid"/ UnhideWhenUsed="false" Name="Light Shading Accent 1"/ UnhideWhenUsed="false" Name="Light List Accent 1"/ UnhideWhenUsed="false" Name="Light Grid Accent 1"/ UnhideWhenUsed="false" Name="Medium Shading 1 Accent 1"/ UnhideWhenUsed="false" Name="Medium Shading 2 Accent 1"/ UnhideWhenUsed="false" Name="Medium List 1 Accent 1"/ UnhideWhenUsed="false" QFormat="true" Name="List Paragraph"/ UnhideWhenUsed="false" QFormat="true" Name="Quote"/ UnhideWhenUsed="false" QFormat="true" Name="Intense Quote"/ UnhideWhenUsed="false" Name="Medium List 2 Accent 1"/ UnhideWhenUsed="false" Name="Medium Grid 1 Accent 1"/ UnhideWhenUsed="false" Name="Medium Grid 2 Accent 1"/ UnhideWhenUsed="false" Name="Medium Grid 3 Accent 1"/ UnhideWhenUsed="false" Name="Dark List Accent 1"/ UnhideWhenUsed="false" Name="Colorful Shading Accent 1"/ UnhideWhenUsed="false" Name="Colorful List Accent 1"/ UnhideWhenUsed="false" Name="Colorful Grid Accent 1"/ UnhideWhenUsed="false" Name="Light Shading Accent 2"/ UnhideWhenUsed="false" Name="Light List Accent 2"/ UnhideWhenUsed="false" Name="Light Grid Accent 2"/ UnhideWhenUsed="false" Name="Medium Shading 1 Accent 2"/ UnhideWhenUsed="false" Name="Medium Shading 2 Accent 2"/ UnhideWhenUsed="false" Name="Medium List 1 Accent 2"/ UnhideWhenUsed="false" Name="Medium List 2 Accent 2"/ UnhideWhenUsed="false" Name="Medium Grid 1 Accent 2"/ UnhideWhenUsed="false" Name="Medium Grid 2 Accent 2"/ UnhideWhenUsed="false" Name="Medium Grid 3 Accent 2"/ UnhideWhenUsed="false" Name="Dark List Accent 2"/ UnhideWhenUsed="false" Name="Colorful Shading Accent 2"/ UnhideWhenUsed="false" Name="Colorful List Accent 2"/ UnhideWhenUsed="false" Name="Colorful Grid Accent 2"/ UnhideWhenUsed="false" Name="Light Shading Accent 3"/ UnhideWhenUsed="false" Name="Light List Accent 3"/ UnhideWhenUsed="false" Name="Light Grid Accent 3"/ UnhideWhenUsed="false" Name="Medium Shading 1 Accent 3"/ UnhideWhenUsed="false" Name="Medium Shading 2 Accent 3"/ UnhideWhenUsed="false" Name="Medium List 1 Accent 3"/ UnhideWhenUsed="false" Name="Medium List 2 Accent 3"/ UnhideWhenUsed="false" Name="Medium Grid 1 Accent 3"/ UnhideWhenUsed="false" Name="Medium Grid 2 Accent 3"/ UnhideWhenUsed="false" Name="Medium Grid 3 Accent 3"/ UnhideWhenUsed="false" Name="Dark List Accent 3"/ UnhideWhenUsed="false" Name="Colorful Shading Accent 3"/ UnhideWhenUsed="false" Name="Colorful List Accent 3"/ UnhideWhenUsed="false" Name="Colorful Grid Accent 3"/ UnhideWhenUsed="false" Name="Light Shading Accent 4"/ UnhideWhenUsed="false" Name="Light List Accent 4"/ UnhideWhenUsed="false" Name="Light Grid Accent 4"/ UnhideWhenUsed="false" Name="Medium Shading 1 Accent 4"/ UnhideWhenUsed="false" Name="Medium Shading 2 Accent 4"/ UnhideWhenUsed="false" Name="Medium List 1 Accent 4"/ UnhideWhenUsed="false" Name="Medium List 2 Accent 4"/ UnhideWhenUsed="false" Name="Medium Grid 1 Accent 4"/ UnhideWhenUsed="false" Name="Medium Grid 2 Accent 4"/ UnhideWhenUsed="false" Name="Medium Grid 3 Accent 4"/ UnhideWhenUsed="false" Name="Dark List Accent 4"/ UnhideWhenUsed="false" Name="Colorful Shading Accent 4"/ UnhideWhenUsed="false" Name="Colorful List Accent 4"/ UnhideWhenUsed="false" Name="Colorful Grid Accent 4"/ UnhideWhenUsed="false" Name="Light Shading Accent 5"/ UnhideWhenUsed="false" Name="Light List Accent 5"/ UnhideWhenUsed="false" Name="Light Grid Accent 5"/ UnhideWhenUsed="false" Name="Medium Shading 1 Accent 5"/ UnhideWhenUsed="false" Name="Medium Shading 2 Accent 5"/ UnhideWhenUsed="false" Name="Medium List 1 Accent 5"/ UnhideWhenUsed="false" Name="Medium List 2 Accent 5"/ UnhideWhenUsed="false" Name="Medium Grid 1 Accent 5"/ UnhideWhenUsed="false" Name="Medium Grid 2 Accent 5"/ UnhideWhenUsed="false" Name="Medium Grid 3 Accent 5"/ UnhideWhenUsed="false" Name="Dark List Accent 5"/ UnhideWhenUsed="false" Name="Colorful Shading Accent 5"/ UnhideWhenUsed="false" Name="Colorful List Accent 5"/ UnhideWhenUsed="false" Name="Colorful Grid Accent 5"/ UnhideWhenUsed="false" Name="Light Shading Accent 6"/ UnhideWhenUsed="false" Name="Light List Accent 6"/ UnhideWhenUsed="false" Name="Light Grid Accent 6"/ UnhideWhenUsed="false" Name="Medium Shading 1 Accent 6"/ UnhideWhenUsed="false" Name="Medium Shading 2 Accent 6"/ UnhideWhenUsed="false" Name="Medium List 1 Accent 6"/ UnhideWhenUsed="false" Name="Medium List 2 Accent 6"/ UnhideWhenUsed="false" Name="Medium Grid 1 Accent 6"/ UnhideWhenUsed="false" Name="Medium Grid 2 Accent 6"/ UnhideWhenUsed="false" Name="Medium Grid 3 Accent 6"/ UnhideWhenUsed="false" Name="Dark List Accent 6"/ UnhideWhenUsed="false" Name="Colorful Shading Accent 6"/ UnhideWhenUsed="false" Name="Colorful List Accent 6"/ UnhideWhenUsed="false" Name="Colorful Grid Accent 6"/ UnhideWhenUsed="false" QFormat="true" Name="Subtle Emphasis"/ UnhideWhenUsed="false" QFormat="true" Name="Intense Emphasis"/ UnhideWhenUsed="false" QFormat="true" Name="Subtle Reference"/ UnhideWhenUsed="false" QFormat="true" Name="Intense Reference"/ UnhideWhenUsed="false" QFormat="true" Name="Book Title"/ /* Style Definitions */ table.MsoNormalTable {mso-style-name:????; mso-tstyle-rowband-size:0; mso-tstyle-colband-size:0; mso-style-noshow:yes; mso-style-priority:99; mso-style-qformat:yes; mso-style-parent:""; mso-padding-alt:0cm 5.4pt 0cm 5.4pt; mso-para-margin:0cm; mso-para-margin-bottom:.0001pt; mso-pagination:widow-orphan; font-size:10.5pt; mso-bidi-font-size:11.0pt; font-family:"Calibri","sans-serif"; mso-ascii-font-family:Calibri; mso-ascii-theme-font:minor-latin; mso-hansi-font-family:Calibri; mso-hansi-theme-font:minor-latin; mso-font-kerning:1.0pt;}

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  • ??GoldenGate Replicat?HANDLECOLLISIONS??

    - by Liu Maclean(???)
    HANDLECOLLISIONS?????goldengate????????REPLICAT??,???????????????????,???????????????????????????,??????????????????????????reperror????????discard??,????????????????,??????(????error mapping????,???????discard??),??????????????;?????????????????,????????? ??HANDLECOLLISIONS?????: target??delete??(missing delete),??????????discardfile target??update??(missing update) ????????=» update???INSERT ,???????????? ?????????=» ??????????discardfile ????????????target??,???replicat???UPDATE?????????????? ??1 target??delete??(missing delete) : C:\Users\ML>sqlplus / as sysdba SQL*Plus: Release 11.2.0.3.0 Production on Tue Sep 18 13:38:03 2012 Copyright (c) 1982, 2011, Oracle. All rights reserved. Connected to: Oracle Database 11g Enterprise Edition Release 11.2.0.3.0 - 64bit Production With the Partitioning, OLAP, Data Mining and Real Application Testing options SQL> conn sender/oracle Connected. SQL> create table handlec(t1 int primary key,t2 int); Table created. SQL> insert into handlec values(1,2); 1 row created. SQL> insert into handlec values(3,2); 1 row created. SQL> insert into handlec values(4,2); 1 row created. SQL> commit; Commit complete. SQL> select * from handlec; T1 T2 ---------- ---------- 1 2 3 2 4 2 target : SQL> conn receiver/oracle Connected. SQL> create table handlec(t1 int primary key,t2 int); Table created. SQL> insert into handlec values(1,2); 1 row created. SQL> commit; SQL> select * from handlec; T1 T2 ---------- ---------- 1 2 SQL> GGSCI (XIANGBLI-CN) 1> alter extract load2 , begin now EXTRACT altered. GGSCI (XIANGBLI-CN) 4> alter replicat rep2, begin now REPLICAT altered. GGSCI (XIANGBLI-CN) 13> add trandata sender.* Logging of supplemental redo data enabled for table SENDER.HANDLEC. Logging of supplemental redo log data is already enabled for table SENDER.TV. GGSCI (XIANGBLI-CN) 14> start mgr MGR is already running. GGSCI (XIANGBLI-CN) 15> start er * Sending START request to MANAGER ... EXTRACT LOAD2 starting Sending START request to MANAGER ... REPLICAT REP2 starting GGSCI (XIANGBLI-CN) 16> info all Program Status Group Lag at Chkpt Time Since Chkpt MANAGER RUNNING EXTRACT RUNNING LOAD2 00:00:00 00:00:01 REPLICAT RUNNING REP2 00:00:00 00:00:08 ***SOURCE?????TARGET????? SQL> delete handlec where t1=3; 1 row deleted. SQL> commit; Commit complete. ??SQL error 1403??,REPLICAT ABORT 2012-09-18 13:45:48 WARNING OGG-01004 Aborted grouped transaction on 'RECEIVER.HANDLEC', Database error 1403 (OCI Error ORA-01403: no data found, SQL ). 2012-09-18 13:45:48 WARNING OGG-01003 Repositioning to rba 1091 in seqno 3. 2012-09-18 13:45:48 WARNING OGG-01154 SQL error 1403 mapping SENDER.HANDLEC to RECEIVER.HANDLEC OCI Error ORA-01403: no data found, SQL . 2012-09-18 13:45:48 WARNING OGG-01003 Repositioning to rba 1091 in seqno 3. Source Context : SourceModule : [er.errors] SourceID : [er/errors.cpp] SourceFunction : [take_rep_err_action] SourceLine : [623] ThreadBacktrace : [8] elements : [D:\ogg\V34342-01\gglog.dll(??1CContextItem@@UEAA@XZ+0x3272) [0x000000018010BDD2]] : [D:\ogg\V34342-01\gglog.dll(?_MSG_ERR_MAP_TO_TANDEM_FAILED@@YAPEAVCMessage@@PEAVCSourceContext@@AEBV?$CQualDBObjName@$00@ggapp@gglib@ggs@@1W4MessageDisposition@CMessageFactory@@@Z+0x138) [0x00000001800AD508]] : [D:\ogg\V34342-01\replicat.exe(ERCALLBACK+0x6e1e) [0x0000000140099D5E]] : [D:\ogg\V34342-01\replicat.exe(shutdownMonitoring+0x4411) [0x00000001400C9BE1]] : [D:\ogg\V34342-01\replicat.exe(shutdownMonitoring+0x289cd) [0x00000001400EE19D]] : [D:\ogg\V34342-01\replicat.exe(CommonLexerNewSSD+0x9440) [0x00000001402AE980]] : [C:\windows\system32\kernel32.dll(BaseThreadInitThunk+0xd) [0x000000007733652D]] : [C:\windows\SYSTEM32\ntdll.dll(RtlUserThreadStart+0x21) [0x000000007746C521]] 2012-09-18 13:45:48 ERROR OGG-01296 Error mapping from SENDER.HANDLEC to RECEIVER.HANDLEC. *********************************************************************** * ** Run Time Statistics ** * *********************************************************************** Last record for the last committed transaction is the following: ___________________________________________________________________ Trail name : D:\ogg\V34342-01\ex\ze000003 Hdr-Ind : E (x45) Partition : . (x04) UndoFlag : . (x00) BeforeAfter: B (x42) RecLength : 9 (x0009) IO Time : 2012-09-18 13:45:38.000000 IOType : 3 (x03) OrigNode : 255 (xff) TransInd : . (x03) FormatType : R (x52) SyskeyLen : 0 (x00) Incomplete : . (x00) AuditRBA : 44 AuditPos : 3337232 Continued : N (x00) RecCount : 1 (x01) 2012-09-18 13:45:38.000000 Delete Len 9 RBA 1091 Name: SENDER.HANDLEC ___________________________________________________________________ Reading D:\ogg\V34342-01\ex\ze000003, current RBA 1091, 0 records Report at 2012-09-18 13:45:48 (activity since 2012-09-18 13:45:48) From Table SENDER.HANDLEC to RECEIVER.HANDLEC: # inserts: 0 # updates: 0 # deletes: 0 # discards: 1 Last log location read: FILE: D:\ogg\V34342-01\ex\ze000003 SEQNO: 3 RBA: 1091 TIMESTAMP: 2012-09-18 13:45:38.000000 EOF: NO READERR: 0 2012-09-18 13:45:48 ERROR OGG-01668 PROCESS ABENDING. 2012-09-18 13:45:48 INFO OGG-01237 Trace file D:\ogg\V34342-01\REP_TRACE1.TRC closed. 2012-09-18 13:45:48 INFO OGG-01237 Trace file D:\ogg\V34342-01\REP_TRACE2.TRC closed. CACHE OBJECT MANAGER statistics CACHE MANAGER VM USAGE vm current = 0 vm anon queues = 0 vm anon in use = 0 vm file = 0 vm used max = 0 ==> CACHE BALANCED CACHE CONFIGURATION cache size = 2G cache force paging = 3.41G buffer min = 64K buffer highwater = 8M pageout eligible size = 8M ================================================================================ ??skiptransaction???????? GGSCI (XIANGBLI-CN) 18> start rep2 skiptransaction Sending START request to MANAGER ... REPLICAT REP2 starting ??2 target??update??(missing update),???????? : ???????, ??source????????? SQL> update handlec set t1=5 where t1=4; 1 row updated. SQL> commit; Commit complete. ???target ????(miss update)??????? Database error 1403+OGG-01296 2012-09-18 13:49:30 WARNING OGG-01004 Aborted grouped transaction on 'RECEIVER.HANDLEC', Database error 1403 (OCI Error ORA-01403: no data found, SQL <UPDATE "RECEIVER"."HANDLEC" SET "T1" = :a1 WHERE "T1" = :b0>). 2012-09-18 13:49:30 WARNING OGG-01003 Repositioning to rba 1218 in seqno 3. 2012-09-18 13:49:30 WARNING OGG-01003 Repositioning to rba 1218 in seqno 3. Source Context : SourceModule : [er.errors] SourceID : [er/errors.cpp] SourceFunction : [take_rep_err_action] SourceLine : [623] ThreadBacktrace : [8] elements : [D:\ogg\V34342-01\gglog.dll(??1CContextItem@@UEAA@XZ+0x3272) [0x000000018010BDD2]] : [D:\ogg\V34342-01\gglog.dll(?_MSG_ERR_MAP_TO_TANDEM_FAILED@@YAPEAVCMessage@@PEAVCSourceContext@@AEBV?$CQualDBObjName@$00@ggapp@gglib@ggs@@1W4MessageDisposition@CMessageFactory@@@Z+0x138) [0x00000001800AD508]] : [D:\ogg\V34342-01\replicat.exe(ERCALLBACK+0x6e1e) [0x0000000140099D5E]] : [D:\ogg\V34342-01\replicat.exe(shutdownMonitoring+0x4411) [0x00000001400C9BE1]] : [D:\ogg\V34342-01\replicat.exe(shutdownMonitoring+0x289cd) [0x00000001400EE19D]] : [D:\ogg\V34342-01\replicat.exe(CommonLexerNewSSD+0x9440) [0x00000001402AE980]] : [C:\windows\system32\kernel32.dll(BaseThreadInitThunk+0xd) [0x000000007733652D]] : [C:\windows\SYSTEM32\ntdll.dll(RtlUserThreadStart+0x21) [0x000000007746C521]] 2012-09-18 13:49:30 ERROR OGG-01296 Error mapping from SENDER.HANDLEC to RECEIVER.HANDLEC. ??HANDLECOLLISIONS?,rep??????????discard?? GGSCI (XIANGBLI-CN) 23> view params rep2 replicat rep2 userid receiver , password oracle trace ./rep_trace1.trc trace2 ./rep_trace2.trc ASSUMETARGETDEFS HANDLECOLLISIONS map sender.*, target receiver.*; GGSCI (XIANGBLI-CN) 18> start rep2 SQL> select * from handlec; T1 T2 ---------- ---------- 1 2 5 ????T1=5 T2 NULL?????? ,??update?????????????,??replicat??????????????update????????????????,?????T2 ?NULL ,????????????EXTRACT??PKUPDATE??? ????????FETCHOPTIONS FETCHPKUPDATECOLS ????????EXTRACT?????,???EXTRACT? ????extract???????????? ??????: SQL> conn receiver/oracle Connected. SQL> select * from handlec; T1 T2 ---------- ---------- 1 2 10 100 5 20 200 SQL> delete handlec where t1=5; 1 row deleted. SQL> commit; Commit complete. SQL> select * from handlec; T1 T2 ---------- ---------- 1 2 10 100 20 200 SQL> conn sender/oracle Connected. SQL> update handlec set t1=t1+1000 where t1=5; 1 row updated. SQL> commit; Commit complete. SQL> conn receiver/oracle Connected. SQL> SQL> SQL> select * from handlec; T1 T2 ---------- ---------- 1 2 10 100 20 200 1005 2 ???????FETCHOPTIONS FETCHPKUPDATECOLS??????redo image???trail?,????primary key?????HANDLECOLLISIONS????target??????????? ??3 ????????????target??,???replicat???UPDATE??????????????: *** TARGET SQL> conn receiver/oracle Connected. SQL> select * from handlec; T1 T2 ---------- ---------- 1 2 10 9 5 target????? t1=10 t2=9??? ,????source???(10,100)??? >>SOURCE SQL> insert into handlec values(10,100); 1 row created. SQL> commit; >>TARGET SQL> select * from handlec; T1 T2 ---------- ---------- 1 2 10 100 5 ???????source?insert??,???target???????????????HANDLECOLLISIONS?REPLICAT???UPDATE??????COLUMNS ?? HANDLECOLLISIONS?????goldengate????????REPLICAT??,???????????????????,???????????????????????????,??????????????????????????reperror????????discard??,????????????????,??????,??????????????;?????????????????,????????? ??HANDLECOLLISIONS?????: target??delete??(missing delete),??????????discardfile target??update??(missing update) ????????=» update???INSERT ,???????????? ?????????=» ??????????discardfile ????????????target??,???replicat???UPDATE?????????????? ?:???????????Insert/Delete??,????????????????Replicat?????abend,????? ???????????,??target??HANDLECOLLISIONS??update??,?????INSERT??????,???????????????,FETCHOPTIONS FETCHPKUPDATECOLS??????redo image???trail?,????primary key?????HANDLECOLLISIONS????target??????????? ??????send ??????HANDLECOLLISIONS GGSCI (XIANGBLI-CN) 29> send rep2, NOHANDLECOLLISIONS Sending NOHANDLECOLLISIONS request to REPLICAT REP2 ... REP2 NOHANDLECOLLISIONS set for 1 tables and 0 wildcard entries

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  • ??OPEN CURSOR?BULK COLLECT

    - by Liu Maclean(???)
    ????T.askmaclean.com?????bulk collect?open cursor???, ?????????  ??????: ???? OPEN_CURSOR ????SQL?? ???????. ?????? ????? ???????????????? ????? test_soruce create table zengfankun_temp01 as select * from dba_objects;select count(*) from zengfankun_temp01;–12,6826analyze table zengfankun_temp01 compute statistics; create or replace procedure test_open_cursor istype type_owner is table of zengfankun_temp01.owner%type index by binary_integer;type type_object_name is table of zengfankun_temp01.object_name%type index by binary_integer;type type_object_id is table of zengfankun_temp01.object_id%type index by binary_integer;type type_object_type is table of zengfankun_temp01.object_type%type index by binary_integer;type type_last_ddl_time is table of zengfankun_temp01.last_ddl_time%type index by binary_integer; l_ary_owner type_owner;l_ary_object_name type_object_name;l_ary_object_id type_object_id;l_ary_object_type type_object_type;l_ary_last_ddl_time type_last_ddl_time; cursor cur_object isselect owner,object_name,object_id,object_type,last_ddl_timefrom zengfankun_temp01order by owner,object_name,object_type,last_ddl_time;OPEN_START number;OPEN_END number;FETCH_START number;FETCH_END number;beginDBMS_OUTPUT.ENABLE (buffer_size=>null) ;OPEN_START:=dbms_utility.get_time();open cur_object;OPEN_END :=dbms_utility.get_time();dbms_output.put_line(‘OPEN_TIME:’||TO_CHAR(OPEN_END-OPEN_START));loopFETCH_START:=dbms_utility.get_time();fetch cur_object bulk collect intol_ary_owner,l_ary_object_name,l_ary_object_id,l_ary_object_type,l_ary_last_ddl_timelimit 10000;FETCH_END:=dbms_utility.get_time();dbms_output.put_line(‘FETCH_TIME:’||TO_CHAR(FETCH_END-FETCH_START)||’ ROWCOUNT:’||cur_object%rowCount); exit when cur_object%notfound or cur_object%notfound is null;end loop;end test_open_cursor; OPEN_TIME:12FETCH_TIME:21 ROWCOUNT:10000FETCH_TIME:3 ROWCOUNT:20000FETCH_TIME:3 ROWCOUNT:30000FETCH_TIME:3 ROWCOUNT:40000FETCH_TIME:3 ROWCOUNT:50000FETCH_TIME:3 ROWCOUNT:60000FETCH_TIME:3 ROWCOUNT:70000FETCH_TIME:3 ROWCOUNT:80000FETCH_TIME:3 ROWCOUNT:90000FETCH_TIME:3 ROWCOUNT:100000FETCH_TIME:3 ROWCOUNT:110000FETCH_TIME:3 ROWCOUNT:120000FETCH_TIME:1 ROWCOUNT:126826 ???? OPEN_TIME:0FETCH_TIME:18 ROWCOUNT:10000FETCH_TIME:3 ROWCOUNT:20000FETCH_TIME:3 ROWCOUNT:30000FETCH_TIME:3 ROWCOUNT:40000FETCH_TIME:3 ROWCOUNT:50000FETCH_TIME:3 ROWCOUNT:60000FETCH_TIME:3 ROWCOUNT:70000FETCH_TIME:3 ROWCOUNT:80000FETCH_TIME:3 ROWCOUNT:90000FETCH_TIME:3 ROWCOUNT:100000FETCH_TIME:3 ROWCOUNT:110000FETCH_TIME:3 ROWCOUNT:120000FETCH_TIME:2 ROWCOUNT:126826 SQL?????????, ????????????.??OPEN CURSOR ????0???????????3??.??N? ??????. ???? ?N? ?????????? ??????. ??????????????? ??????????. ?????????10000??? ???????????????????clear???, ???????????: ?OPEN CURSOR ?????, PL/SQL????SQL????PARSE SQL????????, ??????OPEN CURSOR????SNAPSHOT SCN ??SCN, ??Oracle?????FETCH?????,???????????????? ????FETCH ??????????????,???????Current Block, The most recent version of block , ?????SCN >> Snapshot scn, ????UNDO???? ???SCN ???Best Block ,???Read Consistentcy;???? ???UNDO SNAPSHOT???????????????Best Block??,???????ORA-1555??? ????????, ??????????,???????????????char(2000)????, ???????????????,????bulk collect fetch??fetch 10 ???,????????OPEN CURSOR?????PARSE??SQL????????, ??????????fetch bulk collect??????????10????,??”_trace_pin_time”????Server Process?pin CR block???,??????????Fetch Bulk Collect limit 10??10?buffer?pin? [oracle@nas ~]$ sqlplus / as sysdba SQL*Plus: Release 11.2.0.3.0 Production on Wed Aug 1 11:36:52 2012 Copyright (c) 1982, 2011, Oracle. All rights reserved. Connected to: Oracle Database 11g Enterprise Edition Release 11.2.0.3.0 - 64bit Production With the Partitioning, OLAP, Data Mining and Real Application Testing options SQL> select * from global_name; GLOBAL_NAME -------------------------------------------------------------------------------- http://www.askmaclean.com SQL> create table maclean (t1 char(2000)) tablespace users pctfree 99; Table created. SQL> begin 2 for i in 1..200 loop 3 insert into maclean values('MACLEAN'); 4 commit ; 5 end loop; 6 end; 7 / PL/SQL procedure successfully completed. SQL> exec dbms_stats.gather_table_stats('','MACLEAN'); PL/SQL procedure successfully completed. SQL> select count(*) from maclean; COUNT(*) ---------- 200 SQL> select blocks,num_rows from dba_tables where table_name='MACLEAN'; BLOCKS NUM_ROWS ---------- ---------- 244 200 SQL> alter system set "_trace_pin_time"=1 scope=spfile; System altered. SQL> startup force; ORACLE instance started. Total System Global Area 3140026368 bytes Fixed Size 2232472 bytes Variable Size 1795166056 bytes Database Buffers 1325400064 bytes Redo Buffers 17227776 bytes Database mounted. Database opened. SQL> alter session set events '10046 trace name context forever,level 12'; Session altered. SQL> SQL> SQL> declare 2 cursor v_cursor is 3 select * from sys.maclean; 4 type v_type is table of sys.maclean%rowtype index by binary_integer; 5 rec_tab v_type; 6 begin 7 open v_cursor; 8 dbms_lock.sleep(30); 9 loop 10 fetch v_cursor bulk collect 11 into rec_tab limit 10; 12 dbms_lock.sleep(10); 13 exit when v_cursor%notfound; 14 end loop; 15 end; 16 / ?????10046 trace+ pin trace: PARSING IN CURSOR #47499559136872 len=337 dep=0 uid=0 oct=47 lid=0 tim=1343836146412056 hv=496860239 ad='11a11dbb0' sqlid='4zh7954ftuz2g' declare cursor v_cursor is select * from sys.maclean; type v_type is table of sys.maclean%rowtype index by binary_integer; rec_tab v_type; begin open v_cursor; dbms_lock.sleep(30); loop fetch v_cursor bulk collect into rec_tab limit 10; dbms_lock.sleep(10); exit when v_cursor%notfound; end loop; end; END OF STMT PARSE #47499559136872:c=0,e=346,p=0,cr=0,cu=0,mis=0,r=0,dep=0,og=1,plh=0,tim=1343836146412051 ===================== PARSING IN CURSOR #47499559126280 len=25 dep=1 uid=0 oct=3 lid=0 tim=1343836146414939 hv=3296884535 ad='11a11d250' sqlid='2mb1493284xtr' SELECT * FROM SYS.MACLEAN END OF STMT PARSE #47499559126280:c=1999,e=2427,p=0,cr=0,cu=0,mis=1,r=0,dep=1,og=1,plh=2568761675,tim=1343836146414937 EXEC #47499559126280:c=0,e=55,p=0,cr=0,cu=0,mis=0,r=0,dep=1,og=1,plh=2568761675,tim=1343836146415104 ????? ? SELECT * FROM SYS.MACLEAN? PARSE ????? , ????FETCH???????pin ????????, ????OPEN CURSOR????? *** 2012-08-01 11:49:36.424 WAIT #47499559136872: nam='PL/SQL lock timer' ela= 30009361 duration=0 p2=0 p3=0 obj#=-1 tim=1343836176424782 ???30s pin ktewh26: kteinpscan dba 0x10a6202:4 time 1039048805 pin ktewh27: kteinmap dba 0x10a6202:4 time 1039048847 pin kdswh11: kdst_fetch dba 0x10a6203:1 time 1039048898 pin kdswh11: kdst_fetch dba 0x10a6204:1 time 1039048961 pin kdswh11: kdst_fetch dba 0x10a6205:1 time 1039049004 pin kdswh11: kdst_fetch dba 0x10a6206:1 time 1039049042 pin kdswh11: kdst_fetch dba 0x10a6207:1 time 1039049089 pin kdswh11: kdst_fetch dba 0x10a6208:1 time 1039049123 pin kdswh11: kdst_fetch dba 0x10a6209:1 time 1039049159 pin kdswh11: kdst_fetch dba 0x10a620a:1 time 1039049191 pin kdswh11: kdst_fetch dba 0x10a620b:1 time 1039049225 pin kdswh11: kdst_fetch dba 0x10a620c:1 time 1039049260 kdst_fetch???fetch??????? , ??fetch?10?? ???????FETCH FETCH #47499559126280:c=0,e=536,p=0,cr=12,cu=0,mis=0,r=10,dep=1,og=1,plh=2568761675,tim=1343836176425542 *** 2012-08-01 11:49:46.428 WAIT #47499559136872: nam='PL/SQL lock timer' ela= 10002694 duration=0 p2=0 p3=0 obj#=-1 tim=134383618642829 ????10s pin kdswh11: kdst_fetch dba 0x10a620d:1 time 1049052211 pin kdswh11: kdst_fetch dba 0x10a620e:1 time 1049052264 pin kdswh11: kdst_fetch dba 0x10a620f:1 time 1049052299 pin kdswh11: kdst_fetch dba 0x10a6211:1 time 1049052332 pin kdswh11: kdst_fetch dba 0x10a6212:1 time 1049052364 pin kdswh11: kdst_fetch dba 0x10a6213:1 time 1049052398 pin kdswh11: kdst_fetch dba 0x10a6214:1 time 1049052430 pin kdswh11: kdst_fetch dba 0x10a6215:1 time 1049052462 pin kdswh11: kdst_fetch dba 0x10a6216:1 time 1049052494 pin kdswh11: kdst_fetch dba 0x10a6217:1 time 1049052525 FETCH #47499559126280:c=0,e=371,p=0,cr=10,cu=0,mis=0,r=10,dep=1,og=1,plh=2568761675,tim=1343836186428807 ??pin 10????, ???fetch ?? WAIT #47499559136872: nam='PL/SQL lock timer' ela= 10002864 duration=0 p2=0 p3=0 obj#=-1 tim=1343836196431754 pin kdswh11: kdst_fetch dba 0x10a6218:1 time 1059055662 pin kdswh11: kdst_fetch dba 0x10a6219:1 time 1059055714 pin kdswh11: kdst_fetch dba 0x10a621a:1 time 1059055748 pin kdswh11: kdst_fetch dba 0x10a621b:1 time 1059055781 pin kdswh11: kdst_fetch dba 0x10a621c:1 time 1059055815 pin kdswh11: kdst_fetch dba 0x10a621d:1 time 1059055848 pin kdswh11: kdst_fetch dba 0x10a621e:1 time 1059055883 pin kdswh11: kdst_fetch dba 0x10a621f:1 time 1059055915 pin kdswh11: kdst_fetch dba 0x10a6221:1 time 1059055953 pin kdswh11: kdst_fetch dba 0x10a6222:1 time 1059055992 FETCH #47499559126280:c=0,e=385,p=0,cr=10,cu=0,mis=0,r=10,dep=1,og=1,plh=2568761675,tim=1343836196432274 ???? ??????? DBA????? ............................ ???? WAIT #47499559136872: nam='PL/SQL lock timer' ela= 10002933 duration=0 p2=0 p3=0 obj#=-1 tim=1343836366495589 pin kdswh11: kdst_fetch dba 0x10a62f6:1 time 1229119497 pin kdswh11: kdst_fetch dba 0x10a62f7:1 time 1229119545 pin kdswh11: kdst_fetch dba 0x10a62f8:1 time 1229119576 pin kdswh11: kdst_fetch dba 0x10a62f9:1 time 1229119610 pin kdswh11: kdst_fetch dba 0x10a62fa:1 time 1229119644 pin kdswh11: kdst_fetch dba 0x10a62fb:1 time 1229119671 pin kdswh11: kdst_fetch dba 0x10a62fc:1 time 1229119703 pin kdswh11: kdst_fetch dba 0x10a62fd:1 time 1229119730 pin kdswh11: kdst_fetch dba 0x10a62fe:1 time 1229119760 pin kdswh11: kdst_fetch dba 0x10a62ff:1 time 1229119787 FETCH #47499559126280:c=0,e=340,p=0,cr=10,cu=0,mis=0,r=10,dep=1,og=1,plh=2568761675,tim=1343836366496067 ??????DBA? 0x10a6203 , ??DBA ? 0x10a62ff ???????DBA??MACLEAN????????,???DBA???Maclean????? getbfno?????dba??????????? CREATE OR REPLACE FUNCTION getbfno (p_dba IN VARCHAR2) RETURN VARCHAR2 IS l_str VARCHAR2 (255) DEFAULT NULL; l_fno VARCHAR2 (15); l_bno VARCHAR2 (15); BEGIN l_fno := DBMS_UTILITY.data_block_address_file (TO_NUMBER (LTRIM (p_dba, '0x'), 'xxxxxxxx' ) ); l_bno := DBMS_UTILITY.data_block_address_block (TO_NUMBER (LTRIM (p_dba, '0x'), 'xxxxxxxx' ) ); l_str := 'datafile# is:' || l_fno || CHR (10) || 'datablock is:' || l_bno || CHR (10) || 'dump command:alter system dump datafile ' || l_fno || ' block ' || l_bno || ';'; RETURN l_str; END; / Function created. SQL> select getbfno('0x10a6203') from dual; GETBFNO('0X10A6203') -------------------------------------------------------------------------------- datafile# is:4 datablock is:680451 dump command:alter system dump datafile 4 block 680451; SQL> select getbfno('0x10a62ff') from dual; GETBFNO('0X10A62FF') -------------------------------------------------------------------------------- datafile# is:4 datablock is:680703 dump command:alter system dump datafile 4 block 680703; SQL> select dbms_rowid.rowid_block_number(min(rowid)),dbms_rowid.rowid_relative_fno(min(rowid)) from maclean; DBMS_ROWID.ROWID_BLOCK_NUMBER(MIN(ROWID)) ----------------------------------------- DBMS_ROWID.ROWID_RELATIVE_FNO(MIN(ROWID)) ----------------------------------------- 680451 4 SQL> select dbms_rowid.rowid_block_number(max(rowid)),dbms_rowid.rowid_relative_fno(max(rowid)) from maclean; DBMS_ROWID.ROWID_BLOCK_NUMBER(MAX(ROWID)) ----------------------------------------- DBMS_ROWID.ROWID_RELATIVE_FNO(MAX(ROWID)) ----------------------------------------- 680703 4 ???????3???: 1.?OPEN CURSOR ?????, PL/SQL????SQL????PARSE SQL????????, ??????OPEN CURSOR????SNAPSHOT SCN ??SCN, ??Oracle?????FETCH?????,???????????????? 2.????FETCH ?????????????? 3. ???open cursor+ fetch bulk collect???”?????????”

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  • Loading jQuery Consistently in a .NET Web App

    - by Rick Strahl
    One thing that frequently comes up in discussions when using jQuery is how to best load the jQuery library (as well as other commonly used and updated libraries) in a Web application. Specifically the issue is the one of versioning and making sure that you can easily update and switch versions of script files with application wide settings in one place and having your script usage reflect those settings in the entire application on all pages that use the script. Although I use jQuery as an example here, the same concepts can be applied to any script library - for example in my Web libraries I use the same approach for jQuery.ui and my own internal jQuery support library. The concepts used here can be applied both in WebForms and MVC. Loading jQuery Properly From CDN Before we look at a generic way to load jQuery via some server logic, let me first point out my preferred way to embed jQuery into the page. I use the Google CDN to load jQuery and then use a fallback URL to handle the offline or no Internet connection scenario. Why use a CDN? CDN links tend to be loaded more quickly since they are very likely to be cached in user's browsers already as jQuery CDN is used by many, many sites on the Web. Using a CDN also removes load from your Web server and puts the load bearing on the CDN provider - in this case Google - rather than on your Web site. On the downside, CDN links gives the provider (Google, Microsoft) yet another way to track users through their Web usage. Here's how I use jQuery CDN plus a fallback link on my WebLog for example: <!DOCTYPE HTML> <html> <head> <script src="//ajax.googleapis.com/ajax/libs/jquery/1.6.4/jquery.min.js"></script> <script> if (typeof (jQuery) == 'undefined') document.write(unescape("%3Cscript " + "src='/Weblog/wwSC.axd?r=Westwind.Web.Controls.Resources.jquery.js' %3E%3C/script%3E")); </script> <title>Rick Strahl's Web Log</title> ... </head>   You can see that the CDN is referenced first, followed by a small script block that checks to see whether jQuery was loaded (jQuery object exists). If it didn't load another script reference is added to the document dynamically pointing to a backup URL. In this case my backup URL points at a WebResource in my Westwind.Web  assembly, but the URL can also be local script like src="/scripts/jquery.min.js". Important: Use the proper Protocol/Scheme for  for CDN Urls [updated based on comments] If you're using a CDN to load an external script resource you should always make sure that the script is loaded with the same protocol as the parent page to avoid mixed content warnings by the browser. You don't want to load a script link to an http:// resource when you're on an https:// page. The easiest way to use this is by using a protocol relative URL: <script src="//ajax.googleapis.com/ajax/libs/jquery/1.6.4/jquery.min.js"></script> which is an easy way to load resources from other domains. This URL syntax will automatically use the parent page's protocol (or more correctly scheme). As long as the remote domains support both http:// and https:// access this should work. BTW this also works in CSS (with some limitations) and links. BTW, I didn't know about this until it was pointed out in the comments. This is a very useful feature for many things - ah the benefits of my blog to myself :-) Version Numbers When you use a CDN you notice that you have to reference a specific version of jQuery. When using local files you may not have to do this as you can rename your private copy of jQuery.js, but for CDN the references are always versioned. The version number is of course very important to ensure you getting the version you have tested with, but it's also important to the provider because it ensures that cached content is always correct. If an existing file was updated the updates might take a very long time to get past the locally cached content and won't refresh properly. The version number ensures you get the right version and not some cached content that has been changed but not updated in your cache. On the other hand version numbers also mean that once you decide to use a new version of the script you now have to change all your script references in your pages. Depending on whether you use some sort of master/layout page or not this may or may not be easy in your application. Even if you do use master/layout pages, chances are that you probably have a few of them and at the very least all of those have to be updated for the scripts. If you use individual pages for all content this issue then spreads to all of your pages. Search and Replace in Files will do the trick, but it's still something that's easy to forget and worry about. Personaly I think it makes sense to have a single place where you can specify common script libraries that you want to load and more importantly which versions thereof and where they are loaded from. Loading Scripts via Server Code Script loading has always been important to me and as long as I can remember I've always built some custom script loading routines into my Web frameworks. WebForms makes this fairly easy because it has a reasonably useful script manager (ClientScriptManager and the ScriptManager) which allow injecting script into the page easily from anywhere in the Page cycle. What's nice about these components is that they allow scripts to be injected by controls so components can wrap up complex script/resource dependencies more easily without having to require long lists of CSS/Scripts/Image includes. In MVC or pure script driven applications like Razor WebPages  the process is more raw, requiring you to embed script references in the right place. But its also more immediate - it lets you know exactly which versions of scripts to use because you have to manually embed them. In WebForms with different controls loading resources this often can get confusing because it's quite possible to load multiple versions of the same script library into a page, the results of which are less than optimal… In this post I look a simple routine that embeds jQuery into the page based on a few application wide configuration settings. It returns only a string of the script tags that can be manually embedded into a Page template. It's a small function that merely a string of the script tags shown at the begging of this post along with some options on how that string is comprised. You'll be able to specify in one place which version loads and then all places where the help function is used will automatically reflect this selection. Options allow specification of the jQuery CDN Url, the fallback Url and where jQuery should be loaded from (script folder, Resource or CDN in my case). While this is specific to jQuery you can apply this to other resources as well. For example I use a similar approach with jQuery.ui as well using practically the same semantics. Providing Resources in ControlResources In my Westwind.Web Web utility library I have a class called ControlResources which is responsible for holding resource Urls, resource IDs and string contants that reference those resource IDs. The library also provides a few helper methods for loading common scriptscripts into a Web page. There are specific versions for WebForms which use the ClientScriptManager/ScriptManager and script link methods that can be used in any .NET technology that can embed an expression into the output template (or code for that matter). The ControlResources class contains mostly static content - references to resources mostly. But it also contains a few static properties that configure script loading: A Script LoadMode (CDN, Resource, or script url) A default CDN Url A fallback url They are  static properties in the ControlResources class: public class ControlResources { /// <summary> /// Determines what location jQuery is loaded from /// </summary> public static JQueryLoadModes jQueryLoadMode = JQueryLoadModes.ContentDeliveryNetwork; /// <summary> /// jQuery CDN Url on Google /// </summary> public static string jQueryCdnUrl = "//ajax.googleapis.com/ajax/libs/jquery/1.6.4/jquery.min.js"; /// <summary> /// jQuery CDN Url on Google /// </summary> public static string jQueryUiCdnUrl = "//ajax.googleapis.com/ajax/libs/jqueryui/1.8.16/jquery-ui.min.js"; /// <summary> /// jQuery UI fallback Url if CDN is unavailable or WebResource is used /// Note: The file needs to exist and hold the minimized version of jQuery ui /// </summary> public static string jQueryUiLocalFallbackUrl = "~/scripts/jquery-ui.min.js"; } These static properties are fixed values that can be changed at application startup to reflect your preferences. Since they're static they are application wide settings and respected across the entire Web application running. It's best to set these default in Application_Init or similar startup code if you need to change them for your application: protected void Application_Start(object sender, EventArgs e) { // Force jQuery to be loaded off Google Content Network ControlResources.jQueryLoadMode = JQueryLoadModes.ContentDeliveryNetwork; // Allow overriding of the Cdn url ControlResources.jQueryCdnUrl = "http://ajax.googleapis.com/ajax/libs/jquery/1.6.2/jquery.min.js"; // Route to our own internal handler App.OnApplicationStart(); } With these basic settings in place you can then embed expressions into a page easily. In WebForms use: <!DOCTYPE html> <html> <head runat="server"> <%= ControlResources.jQueryLink() %> <script src="scripts/ww.jquery.min.js"></script> </head> In Razor use: <!DOCTYPE html> <html> <head> @Html.Raw(ControlResources.jQueryLink()) <script src="scripts/ww.jquery.min.js"></script> </head> Note that in Razor you need to use @Html.Raw() to force the string NOT to escape. Razor by default escapes string results and this ensures that the HTML content is properly expanded as raw HTML text. Both the WebForms and Razor output produce: <!DOCTYPE html> <html> <head> <script src="http://ajax.googleapis.com/ajax/libs/jquery/1.6.2/jquery.min.js" type="text/javascript"></script> <script type="text/javascript"> if (typeof (jQuery) == 'undefined') document.write(unescape("%3Cscript src='/WestWindWebToolkitWeb/WebResource.axd?d=-b6oWzgbpGb8uTaHDrCMv59VSmGhilZP5_T_B8anpGx7X-PmW_1eu1KoHDvox-XHqA1EEb-Tl2YAP3bBeebGN65tv-7-yAimtG4ZnoWH633pExpJor8Qp1aKbk-KQWSoNfRC7rQJHXVP4tC0reYzVw2&t=634535391996872492' type='text/javascript'%3E%3C/script%3E"));</script> <script src="scripts/ww.jquery.min.js"></script> </head> which produces the desired effect for both CDN load and fallback URL. The implementation of jQueryLink is pretty basic of course: /// <summary> /// Inserts a script link to load jQuery into the page based on the jQueryLoadModes settings /// of this class. Default load is by CDN plus WebResource fallback /// </summary> /// <param name="url"> /// An optional explicit URL to load jQuery from. Url is resolved. /// When specified no fallback is applied /// </param> /// <returns>full script tag and fallback script for jQuery to load</returns> public static string jQueryLink(JQueryLoadModes jQueryLoadMode = JQueryLoadModes.Default, string url = null) { string jQueryUrl = string.Empty; string fallbackScript = string.Empty; if (jQueryLoadMode == JQueryLoadModes.Default) jQueryLoadMode = ControlResources.jQueryLoadMode; if (!string.IsNullOrEmpty(url)) jQueryUrl = WebUtils.ResolveUrl(url); else if (jQueryLoadMode == JQueryLoadModes.WebResource) { Page page = new Page(); jQueryUrl = page.ClientScript.GetWebResourceUrl(typeof(ControlResources), ControlResources.JQUERY_SCRIPT_RESOURCE); } else if (jQueryLoadMode == JQueryLoadModes.ContentDeliveryNetwork) { jQueryUrl = ControlResources.jQueryCdnUrl; if (!string.IsNullOrEmpty(jQueryCdnUrl)) { // check if jquery loaded - if it didn't we're not online and use WebResource fallbackScript = @"<script type=""text/javascript"">if (typeof(jQuery) == 'undefined') document.write(unescape(""%3Cscript src='{0}' type='text/javascript'%3E%3C/script%3E""));</script>"; fallbackScript = string.Format(fallbackScript, WebUtils.ResolveUrl(ControlResources.jQueryCdnFallbackUrl)); } } string output = "<script src=\"" + jQueryUrl + "\" type=\"text/javascript\"></script>"; // add in the CDN fallback script code if (!string.IsNullOrEmpty(fallbackScript)) output += "\r\n" + fallbackScript + "\r\n"; return output; } There's one dependency here on WebUtils.ResolveUrl() which resolves Urls without access to a Page/Control (another one of those features that should be in the runtime, not in the WebForms or MVC engine). You can see there's only a little bit of logic in this code that deals with potentially different load modes. I can load scripts from a Url, WebResources or - my preferred way - from CDN. Based on the static settings the scripts to embed are composed to be returned as simple string <script> tag(s). I find this extremely useful especially when I'm not connected to the internet so that I can quickly swap in a local jQuery resource instead of loading from CDN. While CDN loading with the fallback works it can be a bit slow as the CDN is probed first before the fallback kicks in. Switching quickly in one place makes this trivial. It also makes it very easy once a new version of jQuery rolls around to move up to the new version and ensure that all pages are using the new version immediately. I'm not trying to make this out as 'the' definite way to load your resources, but rather provide it here as a pointer so you can maybe apply your own logic to determine where scripts come from and how they load. You could even automate this some more by using configuration settings or reading the locations/preferences out of some sort of data/metadata store that can be dynamically updated instead via recompilation. FWIW, I use a very similar approach for loading jQuery UI and my own ww.jquery library - the same concept can be applied to any kind of script you might be loading from different locations. Hopefully some of you find this a useful addition to your toolset. Resources Google CDN for jQuery Full ControlResources Source Code ControlResource Documentation Westwind.Web NuGet This method is part of the Westwind.Web library of the West Wind Web Toolkit or you can grab the Web library from NuGet and add to your Visual Studio project. This package includes a host of Web related utilities and script support features. © Rick Strahl, West Wind Technologies, 2005-2011Posted in ASP.NET  jQuery   Tweet (function() { var po = document.createElement('script'); po.type = 'text/javascript'; po.async = true; po.src = 'https://apis.google.com/js/plusone.js'; var s = document.getElementsByTagName('script')[0]; s.parentNode.insertBefore(po, s); })();

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  • Inheritance Mapping Strategies with Entity Framework Code First CTP5 Part 1: Table per Hierarchy (TPH)

    - by mortezam
    A simple strategy for mapping classes to database tables might be “one table for every entity persistent class.” This approach sounds simple enough and, indeed, works well until we encounter inheritance. Inheritance is such a visible structural mismatch between the object-oriented and relational worlds because object-oriented systems model both “is a” and “has a” relationships. SQL-based models provide only "has a" relationships between entities; SQL database management systems don’t support type inheritance—and even when it’s available, it’s usually proprietary or incomplete. There are three different approaches to representing an inheritance hierarchy: Table per Hierarchy (TPH): Enable polymorphism by denormalizing the SQL schema, and utilize a type discriminator column that holds type information. Table per Type (TPT): Represent "is a" (inheritance) relationships as "has a" (foreign key) relationships. Table per Concrete class (TPC): Discard polymorphism and inheritance relationships completely from the SQL schema.I will explain each of these strategies in a series of posts and this one is dedicated to TPH. In this series we'll deeply dig into each of these strategies and will learn about "why" to choose them as well as "how" to implement them. Hopefully it will give you a better idea about which strategy to choose in a particular scenario. Inheritance Mapping with Entity Framework Code FirstAll of the inheritance mapping strategies that we discuss in this series will be implemented by EF Code First CTP5. The CTP5 build of the new EF Code First library has been released by ADO.NET team earlier this month. EF Code-First enables a pretty powerful code-centric development workflow for working with data. I’m a big fan of the EF Code First approach, and I’m pretty excited about a lot of productivity and power that it brings. When it comes to inheritance mapping, not only Code First fully supports all the strategies but also gives you ultimate flexibility to work with domain models that involves inheritance. The fluent API for inheritance mapping in CTP5 has been improved a lot and now it's more intuitive and concise in compare to CTP4. A Note For Those Who Follow Other Entity Framework ApproachesIf you are following EF's "Database First" or "Model First" approaches, I still recommend to read this series since although the implementation is Code First specific but the explanations around each of the strategies is perfectly applied to all approaches be it Code First or others. A Note For Those Who are New to Entity Framework and Code-FirstIf you choose to learn EF you've chosen well. If you choose to learn EF with Code First you've done even better. To get started, you can find a great walkthrough by Scott Guthrie here and another one by ADO.NET team here. In this post, I assume you already setup your machine to do Code First development and also that you are familiar with Code First fundamentals and basic concepts. You might also want to check out my other posts on EF Code First like Complex Types and Shared Primary Key Associations. A Top Down Development ScenarioThese posts take a top-down approach; it assumes that you’re starting with a domain model and trying to derive a new SQL schema. Therefore, we start with an existing domain model, implement it in C# and then let Code First create the database schema for us. However, the mapping strategies described are just as relevant if you’re working bottom up, starting with existing database tables. I’ll show some tricks along the way that help you dealing with nonperfect table layouts. Let’s start with the mapping of entity inheritance. -- The Domain ModelIn our domain model, we have a BillingDetail base class which is abstract (note the italic font on the UML class diagram below). We do allow various billing types and represent them as subclasses of BillingDetail class. As for now, we support CreditCard and BankAccount: Implement the Object Model with Code First As always, we start with the POCO classes. Note that in our DbContext, I only define one DbSet for the base class which is BillingDetail. Code First will find the other classes in the hierarchy based on Reachability Convention. public abstract class BillingDetail  {     public int BillingDetailId { get; set; }     public string Owner { get; set; }             public string Number { get; set; } } public class BankAccount : BillingDetail {     public string BankName { get; set; }     public string Swift { get; set; } } public class CreditCard : BillingDetail {     public int CardType { get; set; }                     public string ExpiryMonth { get; set; }     public string ExpiryYear { get; set; } } public class InheritanceMappingContext : DbContext {     public DbSet<BillingDetail> BillingDetails { get; set; } } This object model is all that is needed to enable inheritance with Code First. If you put this in your application you would be able to immediately start working with the database and do CRUD operations. Before going into details about how EF Code First maps this object model to the database, we need to learn about one of the core concepts of inheritance mapping: polymorphic and non-polymorphic queries. Polymorphic Queries LINQ to Entities and EntitySQL, as object-oriented query languages, both support polymorphic queries—that is, queries for instances of a class and all instances of its subclasses, respectively. For example, consider the following query: IQueryable<BillingDetail> linqQuery = from b in context.BillingDetails select b; List<BillingDetail> billingDetails = linqQuery.ToList(); Or the same query in EntitySQL: string eSqlQuery = @"SELECT VAlUE b FROM BillingDetails AS b"; ObjectQuery<BillingDetail> objectQuery = ((IObjectContextAdapter)context).ObjectContext                                                                          .CreateQuery<BillingDetail>(eSqlQuery); List<BillingDetail> billingDetails = objectQuery.ToList(); linqQuery and eSqlQuery are both polymorphic and return a list of objects of the type BillingDetail, which is an abstract class but the actual concrete objects in the list are of the subtypes of BillingDetail: CreditCard and BankAccount. Non-polymorphic QueriesAll LINQ to Entities and EntitySQL queries are polymorphic which return not only instances of the specific entity class to which it refers, but all subclasses of that class as well. On the other hand, Non-polymorphic queries are queries whose polymorphism is restricted and only returns instances of a particular subclass. In LINQ to Entities, this can be specified by using OfType<T>() Method. For example, the following query returns only instances of BankAccount: IQueryable<BankAccount> query = from b in context.BillingDetails.OfType<BankAccount>() select b; EntitySQL has OFTYPE operator that does the same thing: string eSqlQuery = @"SELECT VAlUE b FROM OFTYPE(BillingDetails, Model.BankAccount) AS b"; In fact, the above query with OFTYPE operator is a short form of the following query expression that uses TREAT and IS OF operators: string eSqlQuery = @"SELECT VAlUE TREAT(b as Model.BankAccount)                       FROM BillingDetails AS b                       WHERE b IS OF(Model.BankAccount)"; (Note that in the above query, Model.BankAccount is the fully qualified name for BankAccount class. You need to change "Model" with your own namespace name.) Table per Class Hierarchy (TPH)An entire class hierarchy can be mapped to a single table. This table includes columns for all properties of all classes in the hierarchy. The concrete subclass represented by a particular row is identified by the value of a type discriminator column. You don’t have to do anything special in Code First to enable TPH. It's the default inheritance mapping strategy: This mapping strategy is a winner in terms of both performance and simplicity. It’s the best-performing way to represent polymorphism—both polymorphic and nonpolymorphic queries perform well—and it’s even easy to implement by hand. Ad-hoc reporting is possible without complex joins or unions. Schema evolution is straightforward. Discriminator Column As you can see in the DB schema above, Code First has to add a special column to distinguish between persistent classes: the discriminator. This isn’t a property of the persistent class in our object model; it’s used internally by EF Code First. By default, the column name is "Discriminator", and its type is string. The values defaults to the persistent class names —in this case, “BankAccount” or “CreditCard”. EF Code First automatically sets and retrieves the discriminator values. TPH Requires Properties in SubClasses to be Nullable in the Database TPH has one major problem: Columns for properties declared by subclasses will be nullable in the database. For example, Code First created an (INT, NULL) column to map CardType property in CreditCard class. However, in a typical mapping scenario, Code First always creates an (INT, NOT NULL) column in the database for an int property in persistent class. But in this case, since BankAccount instance won’t have a CardType property, the CardType field must be NULL for that row so Code First creates an (INT, NULL) instead. If your subclasses each define several non-nullable properties, the loss of NOT NULL constraints may be a serious problem from the point of view of data integrity. TPH Violates the Third Normal FormAnother important issue is normalization. We’ve created functional dependencies between nonkey columns, violating the third normal form. Basically, the value of Discriminator column determines the corresponding values of the columns that belong to the subclasses (e.g. BankName) but Discriminator is not part of the primary key for the table. As always, denormalization for performance can be misleading, because it sacrifices long-term stability, maintainability, and the integrity of data for immediate gains that may be also achieved by proper optimization of the SQL execution plans (in other words, ask your DBA). Generated SQL QueryLet's take a look at the SQL statements that EF Code First sends to the database when we write queries in LINQ to Entities or EntitySQL. For example, the polymorphic query for BillingDetails that you saw, generates the following SQL statement: SELECT  [Extent1].[Discriminator] AS [Discriminator],  [Extent1].[BillingDetailId] AS [BillingDetailId],  [Extent1].[Owner] AS [Owner],  [Extent1].[Number] AS [Number],  [Extent1].[BankName] AS [BankName],  [Extent1].[Swift] AS [Swift],  [Extent1].[CardType] AS [CardType],  [Extent1].[ExpiryMonth] AS [ExpiryMonth],  [Extent1].[ExpiryYear] AS [ExpiryYear] FROM [dbo].[BillingDetails] AS [Extent1] WHERE [Extent1].[Discriminator] IN ('BankAccount','CreditCard') Or the non-polymorphic query for the BankAccount subclass generates this SQL statement: SELECT  [Extent1].[BillingDetailId] AS [BillingDetailId],  [Extent1].[Owner] AS [Owner],  [Extent1].[Number] AS [Number],  [Extent1].[BankName] AS [BankName],  [Extent1].[Swift] AS [Swift] FROM [dbo].[BillingDetails] AS [Extent1] WHERE [Extent1].[Discriminator] = 'BankAccount' Note how Code First adds a restriction on the discriminator column and also how it only selects those columns that belong to BankAccount entity. Change Discriminator Column Data Type and Values With Fluent API Sometimes, especially in legacy schemas, you need to override the conventions for the discriminator column so that Code First can work with the schema. The following fluent API code will change the discriminator column name to "BillingDetailType" and the values to "BA" and "CC" for BankAccount and CreditCard respectively: protected override void OnModelCreating(System.Data.Entity.ModelConfiguration.ModelBuilder modelBuilder) {     modelBuilder.Entity<BillingDetail>()                 .Map<BankAccount>(m => m.Requires("BillingDetailType").HasValue("BA"))                 .Map<CreditCard>(m => m.Requires("BillingDetailType").HasValue("CC")); } Also, changing the data type of discriminator column is interesting. In the above code, we passed strings to HasValue method but this method has been defined to accepts a type of object: public void HasValue(object value); Therefore, if for example we pass a value of type int to it then Code First not only use our desired values (i.e. 1 & 2) in the discriminator column but also changes the column type to be (INT, NOT NULL): modelBuilder.Entity<BillingDetail>()             .Map<BankAccount>(m => m.Requires("BillingDetailType").HasValue(1))             .Map<CreditCard>(m => m.Requires("BillingDetailType").HasValue(2)); SummaryIn this post we learned about Table per Hierarchy as the default mapping strategy in Code First. The disadvantages of the TPH strategy may be too serious for your design—after all, denormalized schemas can become a major burden in the long run. Your DBA may not like it at all. In the next post, we will learn about Table per Type (TPT) strategy that doesn’t expose you to this problem. References ADO.NET team blog Java Persistence with Hibernate book a { text-decoration: none; } a:visited { color: Blue; } .title { padding-bottom: 5px; font-family: Segoe UI; font-size: 11pt; font-weight: bold; padding-top: 15px; } .code, .typeName { font-family: consolas; } .typeName { color: #2b91af; } .padTop5 { padding-top: 5px; } .padTop10 { padding-top: 10px; } p.MsoNormal { margin-top: 0in; margin-right: 0in; margin-bottom: 10.0pt; margin-left: 0in; line-height: 115%; font-size: 11.0pt; font-family: "Calibri" , "sans-serif"; }

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  • Help with Design for Vacation Tracking System (C#/.NET/Access/WebServices/SOA/Excel) [closed]

    - by Aaronaught
    I have been tasked with developing a system for tracking our company's paid time-off (vacation, sick days, etc.) At the moment we are using an Excel spreadsheet on a shared network drive, and it works pretty well, but we are concerned that we won't be able to "trust" employees forever and sometimes we run into locking issues when two people try to open the spreadsheet at once. So we are trying to build something a little more robust. I would like some input on this design in terms of maintainability, scalability, extensibility, etc. It's a pretty simple workflow we need to represent right now: I started with a basic MS Access schema like this: Employees (EmpID int, EmpName varchar(50), AllowedDays int) Vacations (VacationID int, EmpID int, BeginDate datetime, EndDate datetime) But we don't want to spend a lot of time building a schema and database like this and have to change it later, so I think I am going to go with something that will be easier to expand through configuration. Right now the vacation table has this schema: Vacations (VacationID int, PropName varchar(50), PropValue varchar(50)) And the table will be populated with data like this: VacationID | PropName | PropValue -----------+--------------+------------------ 1 | EmpID | 4 1 | EmpName | James Jones 1 | Reason | Vacation 1 | BeginDate | 2/24/2010 1 | EndDate | 2/30/2010 1 | Destination | Spectate Swamp 2 | ... | ... I think this is a pretty good, extensible design, we can easily add new properties to the vacation like the destination or maybe approval status, etc. I wasn't too sure how to go about managing the database of valid properties, I thought of putting them in a separate PropNames table but it gets complicated to manage all the different data types and people say that you shouldn't put CLR type names into a SQL database, so I decided to use XML instead, here is the schema: <VacationProperties> <PropertyNames>EmpID,EmpName,Reason,BeginDate,EndDate,Destination</PropertyNames> <PropertyTypes>System.Int32,System.String,System.String,System.DateTime,System.DateTime,System.String</PropertyTypes> <PropertiesRequired>true,true,false,true,true,false</PropertiesRequired> </VacationProperties> I might need more fields than that, I'm not completely sure. I'm parsing the XML like this (would like some feedback on the parsing code): string xml = File.ReadAllText("properties.xml"); Match m = Regex.Match(xml, "<(PropertyNames)>(.*?)</PropertyNames>"; string[] pn = m.Value.Split(','); // do the same for PropertyTypes, PropertiesRequired Then I use the following code to persist configuration changes to the database: string sql = "DROP TABLE VacationProperties"; sql = sql + " CREATE TABLE VacationProperties "; sql = sql + "(PropertyName varchar(100), PropertyType varchar(100) "; sql = sql + "IsRequired varchar(100))"; for (int i = 0; i < pn.Length; i++) { sql = sql + " INSERT VacationProperties VALUES (" + pn[i] + "," + pt[i] + "," + pv[i] + ")"; } // GlobalConnection is a singleton new SqlCommand(sql, GlobalConnection.Instance).ExecuteReader(); So far so good, but after a few days of this I then realized that a lot of this was just a more specific kind of a generic workflow which could be further abstracted, and instead of writing all of this boilerplate plumbing code I could just come up with a workflow and plug it into a workflow engine like Windows Workflow Foundation and have the users configure it: In order to support routing these configurations throw the workflow system, it seemed natural to implement generic XML Web Services for this instead of just using an XML file as above. I've used this code to implement the Web Services: public class VacationConfigurationService : WebService { [WebMethod] public void UpdateConfiguration(string xml) { // Above code goes here } } Which was pretty easy, although I'm still working on a way to validate that XML against some kind of schema as there's no error-checking yet. I also created a few different services for other operations like VacationSubmissionService, VacationReportService, VacationDataService, VacationAuthenticationService, etc. The whole Service Oriented Architecture looks like this: And because the workflow itself might change, I have been working on a way to integrate the WF workflow system with MS Visio, which everybody at the office already knows how to use so they could make changes pretty easily. We have a diagram that looks like the following (it's kind of hard to read but the main items are Activities, Authenticators, Validators, Transformers, Processors, and Data Connections, they're all analogous to the services in the SOA diagram above). The requirements for this system are: (Note - I don't control these, they were given to me by management) Main workflow must interface with Excel spreadsheet, probably through VBA macros (to ease the transition to the new system) Alerts should integrate with MS Outlook, Lotus Notes, and SMS (text messages). We also want to interface it with the company Voice Mail system but that is not a "hard" requirement. Performance requirements: Must handle 250,000 Transactions Per Second Should be able to handle up to 20,000 employees (right now we have 3) 99.99% uptime ("four nines") expected Must be secure against outside hacking, but users cannot be required to enter a username/password. Platforms: Must support Windows XP/Vista/7, Linux, iPhone, Blackberry, DOS 2.0, VAX, IRIX, PDP-11, Apple IIc. Time to complete: 6 to 8 weeks. My questions are: Is this a good design for the system so far? Am I using all of the recommended best practices for these technologies? How do I integrate the Visio diagram above with the Windows Workflow Foundation to call the ConfigurationService and persist workflow changes? Am I missing any important components? Will this be extensible enough to support any scenario via end-user configuration? Will the system scale to the above performance requirements? Will we need any expensive hardware to run it? Are there any "gotchas" I should know about with respect to cross-platform compatibility? For example would it be difficult to convert this to an iPhone app? How long would you expect this to take? (We've dedicated 1 week for testing so I'm thinking maybe 5 weeks?) Many thanks for your advices, Aaron

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  • Inheritance Mapping Strategies with Entity Framework Code First CTP5: Part 3 – Table per Concrete Type (TPC) and Choosing Strategy Guidelines

    - by mortezam
    This is the third (and last) post in a series that explains different approaches to map an inheritance hierarchy with EF Code First. I've described these strategies in previous posts: Part 1 – Table per Hierarchy (TPH) Part 2 – Table per Type (TPT)In today’s blog post I am going to discuss Table per Concrete Type (TPC) which completes the inheritance mapping strategies supported by EF Code First. At the end of this post I will provide some guidelines to choose an inheritance strategy mainly based on what we've learned in this series. TPC and Entity Framework in the Past Table per Concrete type is somehow the simplest approach suggested, yet using TPC with EF is one of those concepts that has not been covered very well so far and I've seen in some resources that it was even discouraged. The reason for that is just because Entity Data Model Designer in VS2010 doesn't support TPC (even though the EF runtime does). That basically means if you are following EF's Database-First or Model-First approaches then configuring TPC requires manually writing XML in the EDMX file which is not considered to be a fun practice. Well, no more. You'll see that with Code First, creating TPC is perfectly possible with fluent API just like other strategies and you don't need to avoid TPC due to the lack of designer support as you would probably do in other EF approaches. Table per Concrete Type (TPC)In Table per Concrete type (aka Table per Concrete class) we use exactly one table for each (nonabstract) class. All properties of a class, including inherited properties, can be mapped to columns of this table, as shown in the following figure: As you can see, the SQL schema is not aware of the inheritance; effectively, we’ve mapped two unrelated tables to a more expressive class structure. If the base class was concrete, then an additional table would be needed to hold instances of that class. I have to emphasize that there is no relationship between the database tables, except for the fact that they share some similar columns. TPC Implementation in Code First Just like the TPT implementation, we need to specify a separate table for each of the subclasses. We also need to tell Code First that we want all of the inherited properties to be mapped as part of this table. In CTP5, there is a new helper method on EntityMappingConfiguration class called MapInheritedProperties that exactly does this for us. Here is the complete object model as well as the fluent API to create a TPC mapping: public abstract class BillingDetail {     public int BillingDetailId { get; set; }     public string Owner { get; set; }     public string Number { get; set; } }          public class BankAccount : BillingDetail {     public string BankName { get; set; }     public string Swift { get; set; } }          public class CreditCard : BillingDetail {     public int CardType { get; set; }     public string ExpiryMonth { get; set; }     public string ExpiryYear { get; set; } }      public class InheritanceMappingContext : DbContext {     public DbSet<BillingDetail> BillingDetails { get; set; }              protected override void OnModelCreating(ModelBuilder modelBuilder)     {         modelBuilder.Entity<BankAccount>().Map(m =>         {             m.MapInheritedProperties();             m.ToTable("BankAccounts");         });         modelBuilder.Entity<CreditCard>().Map(m =>         {             m.MapInheritedProperties();             m.ToTable("CreditCards");         });                 } } The Importance of EntityMappingConfiguration ClassAs a side note, it worth mentioning that EntityMappingConfiguration class turns out to be a key type for inheritance mapping in Code First. Here is an snapshot of this class: namespace System.Data.Entity.ModelConfiguration.Configuration.Mapping {     public class EntityMappingConfiguration<TEntityType> where TEntityType : class     {         public ValueConditionConfiguration Requires(string discriminator);         public void ToTable(string tableName);         public void MapInheritedProperties();     } } As you have seen so far, we used its Requires method to customize TPH. We also used its ToTable method to create a TPT and now we are using its MapInheritedProperties along with ToTable method to create our TPC mapping. TPC Configuration is Not Done Yet!We are not quite done with our TPC configuration and there is more into this story even though the fluent API we saw perfectly created a TPC mapping for us in the database. To see why, let's start working with our object model. For example, the following code creates two new objects of BankAccount and CreditCard types and tries to add them to the database: using (var context = new InheritanceMappingContext()) {     BankAccount bankAccount = new BankAccount();     CreditCard creditCard = new CreditCard() { CardType = 1 };                      context.BillingDetails.Add(bankAccount);     context.BillingDetails.Add(creditCard);     context.SaveChanges(); } Running this code throws an InvalidOperationException with this message: The changes to the database were committed successfully, but an error occurred while updating the object context. The ObjectContext might be in an inconsistent state. Inner exception message: AcceptChanges cannot continue because the object's key values conflict with another object in the ObjectStateManager. Make sure that the key values are unique before calling AcceptChanges. The reason we got this exception is because DbContext.SaveChanges() internally invokes SaveChanges method of its internal ObjectContext. ObjectContext's SaveChanges method on its turn by default calls AcceptAllChanges after it has performed the database modifications. AcceptAllChanges method merely iterates over all entries in ObjectStateManager and invokes AcceptChanges on each of them. Since the entities are in Added state, AcceptChanges method replaces their temporary EntityKey with a regular EntityKey based on the primary key values (i.e. BillingDetailId) that come back from the database and that's where the problem occurs since both the entities have been assigned the same value for their primary key by the database (i.e. on both BillingDetailId = 1) and the problem is that ObjectStateManager cannot track objects of the same type (i.e. BillingDetail) with the same EntityKey value hence it throws. If you take a closer look at the TPC's SQL schema above, you'll see why the database generated the same values for the primary keys: the BillingDetailId column in both BankAccounts and CreditCards table has been marked as identity. How to Solve The Identity Problem in TPC As you saw, using SQL Server’s int identity columns doesn't work very well together with TPC since there will be duplicate entity keys when inserting in subclasses tables with all having the same identity seed. Therefore, to solve this, either a spread seed (where each table has its own initial seed value) will be needed, or a mechanism other than SQL Server’s int identity should be used. Some other RDBMSes have other mechanisms allowing a sequence (identity) to be shared by multiple tables, and something similar can be achieved with GUID keys in SQL Server. While using GUID keys, or int identity keys with different starting seeds will solve the problem but yet another solution would be to completely switch off identity on the primary key property. As a result, we need to take the responsibility of providing unique keys when inserting records to the database. We will go with this solution since it works regardless of which database engine is used. Switching Off Identity in Code First We can switch off identity simply by placing DatabaseGenerated attribute on the primary key property and pass DatabaseGenerationOption.None to its constructor. DatabaseGenerated attribute is a new data annotation which has been added to System.ComponentModel.DataAnnotations namespace in CTP5: public abstract class BillingDetail {     [DatabaseGenerated(DatabaseGenerationOption.None)]     public int BillingDetailId { get; set; }     public string Owner { get; set; }     public string Number { get; set; } } As always, we can achieve the same result by using fluent API, if you prefer that: modelBuilder.Entity<BillingDetail>()             .Property(p => p.BillingDetailId)             .HasDatabaseGenerationOption(DatabaseGenerationOption.None); Working With The Object Model Our TPC mapping is ready and we can try adding new records to the database. But, like I said, now we need to take care of providing unique keys when creating new objects: using (var context = new InheritanceMappingContext()) {     BankAccount bankAccount = new BankAccount()      {          BillingDetailId = 1                          };     CreditCard creditCard = new CreditCard()      {          BillingDetailId = 2,         CardType = 1     };                      context.BillingDetails.Add(bankAccount);     context.BillingDetails.Add(creditCard);     context.SaveChanges(); } Polymorphic Associations with TPC is Problematic The main problem with this approach is that it doesn’t support Polymorphic Associations very well. After all, in the database, associations are represented as foreign key relationships and in TPC, the subclasses are all mapped to different tables so a polymorphic association to their base class (abstract BillingDetail in our example) cannot be represented as a simple foreign key relationship. For example, consider the the domain model we introduced here where User has a polymorphic association with BillingDetail. This would be problematic in our TPC Schema, because if User has a many-to-one relationship with BillingDetail, the Users table would need a single foreign key column, which would have to refer both concrete subclass tables. This isn’t possible with regular foreign key constraints. Schema Evolution with TPC is Complex A further conceptual problem with this mapping strategy is that several different columns, of different tables, share exactly the same semantics. This makes schema evolution more complex. For example, a change to a base class property results in changes to multiple columns. It also makes it much more difficult to implement database integrity constraints that apply to all subclasses. Generated SQLLet's examine SQL output for polymorphic queries in TPC mapping. For example, consider this polymorphic query for all BillingDetails and the resulting SQL statements that being executed in the database: var query = from b in context.BillingDetails select b; Just like the SQL query generated by TPT mapping, the CASE statements that you see in the beginning of the query is merely to ensure columns that are irrelevant for a particular row have NULL values in the returning flattened table. (e.g. BankName for a row that represents a CreditCard type). TPC's SQL Queries are Union Based As you can see in the above screenshot, the first SELECT uses a FROM-clause subquery (which is selected with a red rectangle) to retrieve all instances of BillingDetails from all concrete class tables. The tables are combined with a UNION operator, and a literal (in this case, 0 and 1) is inserted into the intermediate result; (look at the lines highlighted in yellow.) EF reads this to instantiate the correct class given the data from a particular row. A union requires that the queries that are combined, project over the same columns; hence, EF has to pad and fill up nonexistent columns with NULL. This query will really perform well since here we can let the database optimizer find the best execution plan to combine rows from several tables. There is also no Joins involved so it has a better performance than the SQL queries generated by TPT where a Join is required between the base and subclasses tables. Choosing Strategy GuidelinesBefore we get into this discussion, I want to emphasize that there is no one single "best strategy fits all scenarios" exists. As you saw, each of the approaches have their own advantages and drawbacks. Here are some rules of thumb to identify the best strategy in a particular scenario: If you don’t require polymorphic associations or queries, lean toward TPC—in other words, if you never or rarely query for BillingDetails and you have no class that has an association to BillingDetail base class. I recommend TPC (only) for the top level of your class hierarchy, where polymorphism isn’t usually required, and when modification of the base class in the future is unlikely. If you do require polymorphic associations or queries, and subclasses declare relatively few properties (particularly if the main difference between subclasses is in their behavior), lean toward TPH. Your goal is to minimize the number of nullable columns and to convince yourself (and your DBA) that a denormalized schema won’t create problems in the long run. If you do require polymorphic associations or queries, and subclasses declare many properties (subclasses differ mainly by the data they hold), lean toward TPT. Or, depending on the width and depth of your inheritance hierarchy and the possible cost of joins versus unions, use TPC. By default, choose TPH only for simple problems. For more complex cases (or when you’re overruled by a data modeler insisting on the importance of nullability constraints and normalization), you should consider the TPT strategy. But at that point, ask yourself whether it may not be better to remodel inheritance as delegation in the object model (delegation is a way of making composition as powerful for reuse as inheritance). Complex inheritance is often best avoided for all sorts of reasons unrelated to persistence or ORM. EF acts as a buffer between the domain and relational models, but that doesn’t mean you can ignore persistence concerns when designing your classes. SummaryIn this series, we focused on one of the main structural aspect of the object/relational paradigm mismatch which is inheritance and discussed how EF solve this problem as an ORM solution. We learned about the three well-known inheritance mapping strategies and their implementations in EF Code First. Hopefully it gives you a better insight about the mapping of inheritance hierarchies as well as choosing the best strategy for your particular scenario. Happy New Year and Happy Code-Firsting! References ADO.NET team blog Java Persistence with Hibernate book a { color: #5A99FF; } a:visited { color: #5A99FF; } .title { padding-bottom: 5px; font-family: Segoe UI; font-size: 11pt; font-weight: bold; padding-top: 15px; } .code, .typeName { font-family: consolas; } .typeName { color: #2b91af; } .padTop5 { padding-top: 5px; } .padTop10 { padding-top: 10px; } .exception { background-color: #f0f0f0; font-style: italic; padding-bottom: 5px; padding-left: 5px; padding-top: 5px; padding-right: 5px; }

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  • OIM 11g notification framework

    - by Rajesh G Kumar
    OIM 11g has introduced an improved and template based Notifications framework. New release has removed the limitation of sending text based emails (out-of-the-box emails) and enhanced to support html features. New release provides in-built out-of-the-box templates for events like 'Reset Password', 'Create User Self Service' , ‘User Deleted' etc. Also provides new APIs to support custom templates to send notifications out of OIM. OIM notification framework supports notification mechanism based on events, notification templates and template resolver. They are defined as follows: Ø Events are defined as XML file and imported as part of MDS database in order to make notification event available for use. Ø Notification templates are created using OIM advance administration console. The template contains the text and the substitution 'variables' which will be replaced with the data provided by the template resolver. Templates support internationalization and can be defined as HTML or in form of simple text. Ø Template resolver is a Java class that is responsible to provide attributes and data to be used at runtime and design time. It must be deployed following the OIM plug-in framework. Resolver data provided at design time is to be used by end user to design notification template with available entity variables and it also provides data at runtime to replace the designed variable with value to be displayed to recipients. Steps to define custom notifications in OIM 11g are: Steps# Steps 1. Define the Notification Event 2. Create the Custom Template Resolver class 3. Create Template with notification contents to be sent to recipients 4. Create Event triggering spots in OIM 1. Notification Event metadata The Notification Event is defined as XML file which need to be imported into MDS database. An event file must be compliant with the schema defined by the notification engine, which is NotificationEvent.xsd. The event file contains basic information about the event.XSD location in MDS database: “/metadata/iam-features-notification/NotificationEvent.xsd”Schema file can be viewed by exporting file from MDS using weblogicExportMetadata.sh script.Sample Notification event metadata definition: 1: <?xml version="1.0" encoding="UTF-8"?> 2: <Events xmlns:xsi=http://www.w3.org/2001/XMLSchema-instance xsi:noNamespaceSchemaLocation="../../../metadata/NotificationEvent.xsd"> 3: <EventType name="Sample Notification"> 4: <StaticData> 5: <Attribute DataType="X2-Entity" EntityName="User" Name="Granted User"/> 6: </StaticData> 7: <Resolver class="com.iam.oim.demo.notification.DemoNotificationResolver"> 8: <Param DataType="91-Entity" EntityName="Resource" Name="ResourceInfo"/> 9: </Resolver> 10: </EventType> 11: </Events> Line# Description 1. XML file notation tag 2. Events is root tag 3. EventType tag is to declare a unique event name which will be available for template designing 4. The StaticData element lists a set of parameters which allow user to add parameters that are not data dependent. In other words, this element defines the static data to be displayed when notification is to be configured. An example of static data is the User entity, which is not dependent on any other data and has the same set of attributes for all event instances and notification templates. Available attributes are used to be defined as substitution tokens in the template. 5. Attribute tag is child tag for StaticData to declare the entity and its data type with unique reference name. User entity is most commonly used Entity as StaticData. 6. StaticData closing tag 7. Resolver tag defines the resolver class. The Resolver class must be defined for each notification. It defines what parameters are available in the notification creation screen and how those parameters are replaced when the notification is to be sent. Resolver class resolves the data dynamically at run time and displays the attributes in the UI. 8. The Param DataType element lists a set of parameters which allow user to add parameters that are data dependent. An example of the data dependent or a dynamic entity is a resource object which user can select at run time. A notification template is to be configured for the resource object. Corresponding to the resource object field, a lookup is displayed on the UI. When a user selects the event the call goes to the Resolver class provided to fetch the fields that are displayed in the Available Data list, from which user can select the attribute to be used on the template. Param tag is child tag to declare the entity and its data type with unique reference name. 9. Resolver closing tag 10 EventType closing tag 11. Events closing tag Note: - DataType needs to be declared as “X2-Entity” for User entity and “91-Entity” for Resource or Organization entities. The dynamic entities supported for lookup are user, resource, and organization. Once notification event metadata is defined, need to be imported into MDS database. Fully qualified resolver class name need to be define for XML but do not need to load the class in OIM yet (it can be loaded later). 2. Coding the notification resolver All event owners have to provide a resolver class which would resolve the data dynamically at run time. Custom resolver class must implement the interface oracle.iam.notification.impl.NotificationEventResolver and override the implemented methods with actual implementation. It has 2 methods: S# Methods Descriptions 1. public List<NotificationAttribute> getAvailableData(String eventType, Map<String, Object> params); This API will return the list of available data variables. These variables will be available on the UI while creating/modifying the Templates and would let user select the variables so that they can be embedded as a token as part of the Messages on the template. These tokens are replaced by the value passed by the resolver class at run time. Available data is displayed in a list. The parameter "eventType" specifies the event Name for which template is to be read.The parameter "params" is the map which has the entity name and the corresponding value for which available data is to be fetched. Sample code snippet: List<NotificationAttribute> list = new ArrayList<NotificationAttribute>(); long objKey = (Long) params.get("resource"); //Form Field details based on Resource object key HashMap<String, Object> formFieldDetail = getObjectFormName(objKey); for (Iterator<?> itrd = formFieldDetail.entrySet().iterator(); itrd.hasNext(); ) { NotificationAttribute availableData = new NotificationAttribute(); Map.Entry formDetailEntrySet = (Entry<?, ?>)itrd.next(); String fieldLabel = (String)formDetailEntrySet.getValue(); availableData.setName(fieldLabel); list.add(availableData); } return list; 2. Public HashMap<String, Object> getReplacedData(String eventType, Map<String, Object> params); This API would return the resolved value of the variables present on the template at the runtime when notification is being sent. The parameter "eventType" specifies the event Name for which template is to be read.The parameter "params" is the map which has the base values such as usr_key, obj_key etc required by the resolver implementation to resolve the rest of the variables in the template. Sample code snippet: HashMap<String, Object> resolvedData = new HashMap<String, Object>();String firstName = getUserFirstname(params.get("usr_key"));resolvedData.put("fname", firstName); String lastName = getUserLastName(params.get("usr_key"));resolvedData.put("lname", lastname);resolvedData.put("count", "1 million");return resolvedData; This code must be deployed as per OIM 11g plug-in framework. The XML file defining the plug-in is as below: <?xml version="1.0" encoding="UTF-8"?> <oimplugins xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"> <plugins pluginpoint="oracle.iam.notification.impl.NotificationEventResolver"> <plugin pluginclass= " com.iam.oim.demo.notification.DemoNotificationResolver" version="1.0" name="Sample Notification Resolver"/> </plugins> </oimplugins> 3. Defining the template To create a notification template: Log in to the Oracle Identity Administration Click the System Management tab and then click the Notification tab From the Actions list on the left pane, select Create On the Create page, enter values for the following fields under the Template Information section: Template Name: Demo template Description Text: Demo template Under the Event Details section, perform the following: From the Available Event list, select the event for which the notification template is to be created from a list of available events. Depending on your selection, other fields are displayed in the Event Details section. Note that the template Sample Notification Event created in the previous step being used as the notification event. The contents of the Available Data drop down are based on the event XML StaticData tag, the drop down basically lists all the attributes of the entities defined in that tag. Once you select an element in the drop down, it will show up in the Selected Data text field and then you can just copy it and paste it into either the message subject or the message body fields prefixing $ symbol. Example if list has attribute like First_Name then message body will contains this as $First_Name which resolver will parse and replace it with actual value at runtime. In the Resource field, select a resource from the lookup. This is the dynamic data defined by the Param DataType element in the XML definition. Based on selected resource getAvailableData method of resolver will be called to fetch the resource object attribute detail, if method is overridden with required implementation. For current scenario, Map<String, Object> params will get populated with object key as value and key as “resource” in the map. This is the only input will be provided to resolver at design time. You need to implement the further logic to fetch the object attributes detail to populate the available Data list. List string should not have space in between, if object attributes has space for attribute name then implement logic to replace the space with ‘_’ before populating the list. Example if attribute name is “First Name” then make it “First_Name” and populate the list. Space is not supported while you try to parse and replace the token at run time with real value. Make a note that the Available Data and Selected Data are used in the substitution tokens definition only, they do not define the final data that will be sent in the notification. OIM will invoke the resolver class to get the data and make the substitutions. Under the Locale Information section, enter values in the following fields: To specify a form of encoding, select either UTF-8 or ASCII. In the Message Subject field, enter a subject for the notification. From the Type options, select the data type in which you want to send the message. You can choose between HTML and Text/Plain. In the Short Message field, enter a gist of the message in very few words. In the Long Message field, enter the message that will be sent as the notification with Available data token which need to be replaced by resolver at runtime. After you have entered the required values in all the fields, click Save. A message is displayed confirming the creation of the notification template. Click OK 4. Triggering the event A notification event can be triggered from different places in OIM. The logic behind the triggering must be coded and plugged into OIM. Examples of triggering points for notifications: Event handlers: post process notifications for specific data updates in OIM users Process tasks: to notify the users that a provisioning task was executed by OIM Scheduled tasks: to notify something related to the task The scheduled job has two parameters: Template Name: defines the notification template to be sent User Login: defines the user record that will provide the data to be sent in the notification Sample Code Snippet: public void execute(String templateName , String userId) { try { NotificationService notService = Platform.getService(NotificationService.class); NotificationEvent eventToSend=this.createNotificationEvent(templateName,userId); notService.notify(eventToSend); } catch (Exception e) { e.printStackTrace(); } } private NotificationEvent createNotificationEvent(String poTemplateName, String poUserId) { NotificationEvent event = new NotificationEvent(); String[] receiverUserIds= { poUserId }; event.setUserIds(receiverUserIds); event.setTemplateName(poTemplateName); event.setSender(null); HashMap<String, Object> templateParams = new HashMap<String, Object>(); templateParams.put("USER_LOGIN",poUserId); event.setParams(templateParams); return event; } public HashMap getAttributes() { return null; } public void setAttributes() {} }

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