Search Results

Search found 41993 results on 1680 pages for 'java db'.

Page 1084/1680 | < Previous Page | 1080 1081 1082 1083 1084 1085 1086 1087 1088 1089 1090 1091  | Next Page >

• minimum required bandwidth for remote database server

  - by user66734

  I want to build a small warehousing application for my company. We have a central warehouse which distributes to 8 sales points across the country. They insist on an in-house solution. I am thinking to setup a central mySQL db Linux server and have the branches connect to it to store sales. Queries to the db from the branches will be minimum, maybe 10 per hour. However I need all the branches to be able to store each sale data ( product ID, customer ID ) in the central db at peak time at most once every five minutes. My question is can I get away with simple 24mbps/768kbps DSL lines? If not what is the bandwith requirement? Can I rely on a load balancing router to combine additional lines if needed? Can you propose some server hardware specs?

  Read the article

• RewriteMap syntax Regex

  - by ienabellamy

  in my .htaccess i've tons of directives, with same syntax: RewriteRule ^(.*)/PRODUCT_1.aspx http://www.site.com/product.php?id_product=2891 RewriteRule ^(.*)/PRODUCT_2.aspx http://www.site.com/product.php?id_product=2896 and everything works. Now, i created a RewriteMap in my because i need to increase velocity (20.000 redirect 301 in htaccess no good), so: RewriteEngine On RewriteMap redirects dbm=db:/var/www/html/presta152/prestashop/redirects.db RewriteCond ${redirects:$1} !="" RewriteRule ^(.*)$ ${redirects:$1} [redirect=permanent,last] and my redirects.db is created by redirects.txt, that contains: /PRODUCT_1.aspx http://www.site.com/product.php?id_product=2891 /PRODUCT_2.aspx http://www.site.com/product.php?id_product=2896 this works if i try to call for example: www.site.com/PRODUCT_1.aspx i'm redirected... but if i try to call www.site.com/everythingpossibileinside/PRODUCT_1.aspx the redirect doesn't work. So, in my .htaccess this rule: RewriteRule ^(.*)/PRODUCT_1.aspx http://www.site.com/product.php?id_product=2891 works, but in my RewriteMap no. I think i must change this directive: RewriteRule ^(.*)$ ${redirects:$1} [redirect=permanent,last] i tried, but unsuccessful. Thanks to all.

  Read the article

• Two way replication

  - by Nidzaaaa

  I have a little problem... I have this case: -2 server instances -2 Databases -1 Table (5 columns) From server 1 I created publication to replicate all columns of table I have in 1. DB From server 2 I created subscription to pull all columns from table which is in server 1 DB But now, I need to publicate one columns of same table from server 2 to server 1 and also it has to be in same DB... I tried with using logic and creating publication for server 2 and subscription on server 1 but there is error appearing "You have selected the Publisher as a Subscriber and entered a subscription database that is the same as the publishing database. Select another subscription database." I hope someone understood my problem and have an answer for me, thanks in advance... p.s. Ask for more info if you need ...

  Read the article

• Passing integer lists in a sql query, best practices

  - by Artiom Chilaru

  I'm currently looking at ways to pass lists of integers in a SQL query, and try to decide which of them is best in which situation, what are the benefots of each, and what are the pitfalls, what should be avoided :) Right now I know of 3 ways that we currently use in our application. 1) Table valued parameter: Create a new Table Valued Parameter in sql server: CREATE TYPE [dbo].[TVP_INT] AS TABLE( [ID] [int] NOT NULL ) Then run the query against it: using (var conn = new SqlConnection(DataContext.GetDefaultConnectionString)) { var comm = conn.CreateCommand(); comm.CommandType = CommandType.Text; comm.CommandText = @" UPDATE DA SET [tsLastImportAttempt] = CURRENT_TIMESTAMP FROM [Account] DA JOIN @values IDs ON DA.ID = IDs.ID"; comm.Parameters.Add(new SqlParameter("values", downloadResults.Select(d => d.ID).ToDataTable()) { TypeName = "TVP_INT" }); conn.Open(); comm.ExecuteScalar(); } The major disadvantages of this method is the fact that Linq doesn't support table valued params (if you create an SP with a TVP param, linq won't be able to run it) :( 2) Convert the list to Binary and use it in Linq! This is a bit better.. Create an SP, and you can run it within linq :) To do this, the SP will have an IMAGE parameter, and we'll be using a user defined function (udf) to convert this to a table.. We currently have implementations of this function written in C++ and in assembly, both have pretty much the same performance :) Basically, each integer is represented by 4 bytes, and passed to the SP. In .NET we have an extension method that convers an IEnumerable to a byte array The extension method: public static Byte[] ToBinary(this IEnumerable intList) { return ToBinaryEnum(intList).ToArray(); } private static IEnumerable<Byte> ToBinaryEnum(IEnumerable<Int32> intList) { IEnumerator<Int32> marker = intList.GetEnumerator(); while (marker.MoveNext()) { Byte[] result = BitConverter.GetBytes(marker.Current); Array.Reverse(result); foreach (byte b in result) yield return b; } } The SP: CREATE PROCEDURE [Accounts-UpdateImportAttempts] @values IMAGE AS BEGIN UPDATE DA SET [tsLastImportAttempt] = CURRENT_TIMESTAMP FROM [Account] DA JOIN dbo.udfIntegerArray(@values, 4) IDs ON DA.ID = IDs.Value4 END And we can use it by running the SP directly, or in any linq query we need using (var db = new DataContext()) { db.Accounts_UpdateImportAttempts(downloadResults.Select(d => d.ID).ToBinary()); // or var accounts = db.Accounts .Where(a => db.udfIntegerArray(downloadResults.Select(d => d.ID).ToBinary(), 4) .Select(i => i.Value4) .Contains(a.ID)); } This method has the benefit of using compiled queries in linq (which will have the same sql definition, and query plan, so will also be cached), and can be used in SPs as well. Both these methods are theoretically unlimited, so you can pass millions of ints at a time :) 3) The simple linq .Contains() It's a more simple approach, and is perfect in simple scenarios. But is of course limited by this. using (var db = new DataContext()) { var accounts = db.Accounts .Where(a => downloadResults.Select(d => d.ID).Contains(a.ID)); } The biggest drawback of this method is that each integer in the downloadResults variable will be passed as a separate int.. In this case, the query is limited by sql (max allowed parameters in a sql query, which is a couple of thousand, if I remember right). So I'd like to ask.. What do you think is the best of these, and what other methods and approaches have I missed?

  Read the article

• Does anyone know how to appropriately deal with user timezones in rails 2.3?

  - by Amazing Jay

  We're building a rails app that needs to display dates (and more importantly, calculate them) in multiple timezones. Can anyone point me towards how to work with user timezones in rails 2.3(.5 or .8) The most inclusive article I've seen detailing how user time zones are supposed to work is here: http://wiki.rubyonrails.org/howtos/time-zones... although it is unclear when this was written or for what version of rails. Specifically it states that: "Time.zone - The time zone that is actually used for display purposes. This may be set manually to override config.time_zone on a per-request basis." Keys terms being "display purposes" and "per-request basis". Locally on my machine, this is true. However on production, neither are true. Setting Time.zone persists past the end of the request (to all subsequent requests) and also affects the way AR saves to the DB (basically treating any date as if it were already in UTC even when its not), thus saving completely inappropriate values. We run Ruby Enterprise Edition on production with passenger. If this is my problem, do we need to switch to JRuby or something else? To illustrate the problem I put the following actions in my ApplicationController right now: def test p_time = Time.now.utc s_time = Time.utc(p_time.year, p_time.month, p_time.day, p_time.hour) logger.error "TIME.ZONE" + Time.zone.inspect logger.error ENV['TZ'].inspect logger.error p_time.inspect logger.error s_time.inspect jl = JunkLead.create! jl.date_at = s_time logger.error s_time.inspect logger.error jl.date_at.inspect jl.save! logger.error s_time.inspect logger.error jl.date_at.inspect render :nothing => true, :status => 200 end def test2 Time.zone = 'Mountain Time (US & Canada)' logger.error "TIME.ZONE" + Time.zone.inspect logger.error ENV['TZ'].inspect render :nothing => true, :status => 200 end def test3 Time.zone = 'UTC' logger.error "TIME.ZONE" + Time.zone.inspect logger.error ENV['TZ'].inspect render :nothing => true, :status => 200 end and they yield the following: Processing ApplicationController#test (for 98.202.196.203 at 2010-12-24 22:15:50) [GET] TIME.ZONE#<ActiveSupport::TimeZone:0x2c57a68 @tzinfo=#<TZInfo::DataTimezone: Etc/UTC>, @name="UTC", @utc_offset=0> nil Fri Dec 24 22:15:50 UTC 2010 Fri Dec 24 22:00:00 UTC 2010 Fri Dec 24 22:00:00 UTC 2010 Fri, 24 Dec 2010 22:00:00 UTC +00:00 Fri Dec 24 22:00:00 UTC 2010 Fri, 24 Dec 2010 22:00:00 UTC +00:00 Completed in 21ms (View: 0, DB: 4) | 200 OK [http://www.dealsthatmatter.com/test] Processing ApplicationController#test2 (for 98.202.196.203 at 2010-12-24 22:15:53) [GET] TIME.ZONE#<ActiveSupport::TimeZone:0x2c580a8 @tzinfo=#<TZInfo::DataTimezone: America/Denver>, @name="Mountain Time (US & Canada)", @utc_offset=-25200> nil Completed in 143ms (View: 1, DB: 3) | 200 OK [http://www.dealsthatmatter.com/test2] Processing ApplicationController#test (for 98.202.196.203 at 2010-12-24 22:15:59) [GET] TIME.ZONE#<ActiveSupport::TimeZone:0x2c580a8 @tzinfo=#<TZInfo::DataTimezone: America/Denver>, @name="Mountain Time (US & Canada)", @utc_offset=-25200> nil Fri Dec 24 22:15:59 UTC 2010 Fri Dec 24 22:00:00 UTC 2010 Fri Dec 24 22:00:00 UTC 2010 Fri, 24 Dec 2010 15:00:00 MST -07:00 Fri Dec 24 22:00:00 UTC 2010 Fri, 24 Dec 2010 15:00:00 MST -07:00 Completed in 20ms (View: 0, DB: 4) | 200 OK [http://www.dealsthatmatter.com/test] Processing ApplicationController#test3 (for 98.202.196.203 at 2010-12-24 22:16:03) [GET] TIME.ZONE#<ActiveSupport::TimeZone:0x2c57a68 @tzinfo=#<TZInfo::DataTimezone: Etc/UTC>, @name="UTC", @utc_offset=0> nil Completed in 17ms (View: 0, DB: 2) | 200 OK [http://www.dealsthatmatter.com/test3] Processing ApplicationController#test (for 98.202.196.203 at 2010-12-24 22:16:04) [GET] TIME.ZONE#<ActiveSupport::TimeZone:0x2c57a68 @tzinfo=#<TZInfo::DataTimezone: Etc/UTC>, @name="UTC", @utc_offset=0> nil Fri Dec 24 22:16:05 UTC 2010 Fri Dec 24 22:00:00 UTC 2010 Fri Dec 24 22:00:00 UTC 2010 Fri, 24 Dec 2010 22:00:00 UTC +00:00 Fri Dec 24 22:00:00 UTC 2010 Fri, 24 Dec 2010 22:00:00 UTC +00:00 Completed in 151ms (View: 0, DB: 4) | 200 OK [http://www.dealsthatmatter.com/test] It should be clear above that the 2nd call to /test shows Time.zone set to Mountain, even though it shouldn't. Additionally, checking the database reveals that the test action when run after test2 saved a JunkLead record with a date of 2010-12-22 15:00:00, which is clearly wrong.

  Read the article

• Dropdownlist post in ASP.NET MVC3 and Entity Framework Model

  - by Josh Blade

  I have 3 tables: RateProfile RateProfileID ProfileName Rate RateID RateProfileID PanelID Other stuff to update Panel PanelID PanelName I have models for each of these. I have an edit page using the RateProfile model. I display the information for RateProfile and also all of the Rates associated with it. This works fine and I can update it fine. However, I also added a dropdown so that I can filter Rates by PanelID. I need it to post back on change so that it can display the filtered rates. I'm using @Html.DropDownList("PanelID", (SelectList)ViewData["PanelDropDown"], new { onchange = "$('#RateForm').submit()" }) for my dropdownlist. Whenever it posts back to my HttpPost Edit method though, it seems to be missing all information about the Rates navigation property. It's weird because I thought it would do exactly what the input/submit button that I have in the form does (which actually passes the entire model back to my HttpPost Edit action and does what I want it to do). The panelID is properly being passed to my HttpPost Edit method and on to the next view, but when I try to query the Model.Rates navigation property is null (only when the post comes from the dropdown. Everything works fine when the post comes from my submit input). Get Edit: public ActionResult Edit(int id, int panelID = 1) { RateProfile rateprofile = db.RateProfiles.Single(r => r.RateProfileID == id); var panels = db.Panels; ViewData["PanelDropDown"] = new SelectList(panels, "PanelID", "PanelName", panelID); ViewBag.PanelID = panelID; return View(rateprofile); } HttpPost Edit: [HttpPost] public ActionResult Edit(RateProfile rateprofile, int panelID) { var panels = db.Panels; ViewData["PanelDropDown"] = new SelectList(panels, "PanelID", "PanelName", panelID); ViewBag.PanelID = panelID; if (ModelState.IsValid) { db.Entry(rateprofile).State = EntityState.Modified; foreach (Rate dimerate in rateprofile.Rates) { db.Entry(dimerate).State = EntityState.Modified; } db.SaveChanges(); return View(rateprofile); } return View(rateprofile); } View: @model PDR.Models.RateProfile @using (Html.BeginForm(null,null,FormMethod.Post, new {id="RateForm"})) { <div> @Html.Label("Panel") @Html.DropDownList("PanelID", (SelectList)ViewData["PanelDropDown"], new { onchange = "$('#RateForm').submit()" }) </div> @{var rates= Model.Rates.Where(a => a.PanelID == ViewBag.PanelID).OrderBy(a => a.minCount).ToList();} @for (int i = 0; i < rates.Count; i++) { <tr> <td> @Html.HiddenFor(modelItem => rates[i].RateProfileID) @Html.HiddenFor(modelItem => rates[i].RateID) @Html.HiddenFor(modelItem => rates[i].PanelID) @Html.EditorFor(modelItem => rates[i].minCount) @Html.ValidationMessageFor(model => rates[i].minCount) </td> <td> @Html.EditorFor(modelItem => rates[i].maxCount) @Html.ValidationMessageFor(model => rates[i].maxCount) </td> <td> @Html.EditorFor(modelItem => rates[i].Amount) @Html.ValidationMessageFor(model => rates[i].Amount) </td> </tr> } <input type="submit" value="Save" /> } To summarize my problem, the below query in my view only works when the post comes from the submit button and not when it comes from my dropdownlist. @{var rates= Model.Rates.Where(a => a.PanelID == ViewBag.PanelID).OrderBy(a => a.minCount).ToList();}

  Read the article

• Entity Framework version 1- Brief Synopsis and Tips &ndash; Part 1

  - by Rohit Gupta

  To Do Eager loading use Projections (for e.g. from c in context.Contacts select c, c.Addresses)  or use Include Query Builder Methods (Include(“Addresses”)) If there is multi-level hierarchical Data then to eager load all the relationships use Include Query Builder methods like customers.Include("Order.OrderDetail") to include Order and OrderDetail collections or use customers.Include("Order.OrderDetail.Location") to include all Order, OrderDetail and location collections with a single include statement =========================================================================== If the query uses Joins then Include() Query Builder method will be ignored, use Nested Queries instead If the query does projections then Include() Query Builder method will be ignored Use Address.ContactReference.Load() OR Contact.Addresses.Load() if you need to Deferred Load Specific Entity – This will result in extra round trips to the database ObjectQuery<> cannot return anonymous types... it will return a ObjectQuery<DBDataRecord> Only Include method can be added to Linq Query Methods Any Linq Query method can be added to Query Builder methods. If you need to append a Query Builder Method (other than Include) after a LINQ method  then cast the IQueryable<Contact> to ObjectQuery<Contact> and then append the Query Builder method to it =========================================================================== Query Builder methods are Select, Where, Include Methods which use Entity SQL as parameters e.g. "it.StartDate, it.EndDate" When Query Builder methods do projection then they return ObjectQuery<DBDataRecord>, thus to iterate over this collection use contact.Item[“Name”].ToString() When Linq To Entities methods do projection, they return collection of anonymous types --- thus the collection is strongly typed and supports Intellisense EF Object Context can track changes only on Entities, not on Anonymous types. If you use a Defining Query for a EntitySet then the EntitySet becomes readonly since a Defining Query is the same as a View (which is treated as a ReadOnly by default). However if you want to use this EntitySet for insert/update/deletes then we need to map stored procs (as created in the DB) to the insert/update/delete functions of the Entity in the Designer You can use either Execute method or ToList() method to bind data to datasources/bindingsources If you use the Execute Method then remember that you can traverse through the ObjectResult<> collection (returned by Execute) only ONCE. In WPF use ObservableCollection to bind to data sources , for keeping track of changes and letting EF send updates to the DB automatically. Use Extension Methods to add logic to Entities. For e.g. create extension methods for the EntityObject class. Create a method in ObjectContext Partial class and pass the entity as a parameter, then call this method as desired from within each entity. ================================================================ DefiningQueries and Stored Procedures: For Custom Entities, one can use DefiningQuery or Stored Procedures. Thus the Custom Entity Collection will be populated using the DefiningQuery (of the EntitySet) or the Sproc. If you use Sproc to populate the EntityCollection then the query execution is immediate and this execution happens on the Server side and any filters applied will be applied in the Client App. If we use a DefiningQuery then these queries are composable, meaning the filters (if applied to the entityset) will all be sent together as a single query to the DB, returning only filtered results. If the sproc returns results that cannot be mapped to existing entity, then we first create the Entity/EntitySet in the CSDL using Designer, then create a dummy Entity/EntitySet using XML in the SSDL. When creating a EntitySet in the SSDL for this dummy entity, use a TSQL that does not return any results, but does return the relevant columns e.g. select ContactID, FirstName, LastName from dbo.Contact where 1=2 Also insure that the Entity created in the SSDL uses the SQL DataTypes and not .NET DataTypes. If you are unable to open the EDMX file in the designer then note the Errors ... they will give precise info on what is wrong. The Thrid option is to simply create a Native Query in the SSDL using <Function Name="PaymentsforContact" IsComposable="false">   <CommandText>SELECT ActivityId, Activity AS ActivityName, ImagePath, Category FROM dbo.Activities </CommandText></FuncTion> Then map this Function to a existing Entity. This is a quick way to get a custom Entity which is regular Entity with renamed columns or additional columns (which are computed columns). The disadvantage to using this is that It will return all the rows from the Defining query and any filter (if defined) will be applied only at the Client side (after getting all the rows from DB). If you you DefiningQuery instead then we can use that as a Composable Query. The Fourth option (for mapping a READ stored proc results to a non-existent Entity) is to create a View in the Database which returns all the fields that the sproc also returns, then update the Model so that the model contains this View as a Entity. Then map the Read Sproc to this View Entity. The other option would be to simply create the View and remove the sproc altogether. ================================================================ To Execute a SProc that does not return a entity, use a EntityCommand to execute that proc. You cannot call a sproc FunctionImport that does not return Entities From Code, the only way is to use SSDL function calls using EntityCommand.  This changes with EntityFramework Version 4 where you can return Scalar Types, Complex Types, Entities or NonQuery ================================================================ UDF when created as a Function in SSDL, we need to set the Name & IsComposable properties for the Function element. IsComposable is always false for Sprocs, for UDF's set this to true. You cannot call UDF "Function" from within code since you cannot import a UDF Function into the CSDL Model (with Version 1 of EF). only stored procedures can be imported and then mapped to a entity ================================================================ Entity Framework requires properties that are involved in association mappings to be mapped in all of the function mappings for the entity (Insert, Update and Delete). Because Payment has an association to Reservation... hence we need to pass both the paymentId and reservationId to the Delete sproc even though just the paymentId is the PK on the Payment Table. ================================================================ When mapping insert, update and delete procs to a Entity, insure that all the three or none are mapped. Further if you have a base class and derived class in the CSDL, then you must map (ins, upd, del) sprocs to all parent and child entities in the inheritance relationship. Note that this limitation that base and derived entity methods must all must be mapped does not apply when you are mapping Read Stored Procedures.... ================================================================ You can write stored procedures SQL directly into the SSDL by creating a Function element in the SSDL and then once created, you can map this Function to a CSDL Entity directly in the designer during Function Import ================================================================ You can do Entity Splitting such that One Entity maps to multiple tables in the DB. For e.g. the Customer Entity currently derives from Contact Entity...in addition it also references the ContactPersonalInfo Entity. One can copy all properties from the ContactPersonalInfo Entity into the Customer Entity and then Delete the CustomerPersonalInfo entity, finall one needs to map the copied properties to the ContactPersonalInfo Table in Table Mapping (by adding another table (ContactPersonalInfo) to the Table Mapping... this is called Entity Splitting. Thus now when you insert a Customer record, it will automatically create SQL to insert records into the Contact, Customers and ContactPersonalInfo tables even though you have a Single Entity called Customer in the CSDL =================================================================== There is Table by Type Inheritance where another EDM Entity can derive from another EDM entity and absorb the inherted entities properties, for example in the Break Away Geek Adventures EDM, the Customer entity derives (inherits) from the Contact Entity and absorbs all the properties of Contact entity. Thus when you create a Customer Entity in Code and then call context.SaveChanges the Object Context will first create the TSQL to insert into the Contact Table followed by a TSQL to insert into the Customer table =================================================================== Then there is the Table per Hierarchy Inheritance..... where different types are created based on a condition (similar applying a condition to filter a Entity to contain filtered records)... the diference being that the filter condition populates a new Entity Type (derived from the base Entity). In the BreakAway sample the example is Lodging Entity which is a Abstract Entity and Then Resort and NonResort Entities which derive from Lodging Entity and records are filtered based on the value of the Resort Boolean field =================================================================== Then there is Table per Concrete Type Hierarchy where we create a concrete Entity for each table in the database. In the BreakAway sample there is a entity for the Reservation table and another Entity for the OldReservation table even though both the table contain the same number of fields. The OldReservation Entity can then inherit from the Reservation Entity and configure the OldReservation Entity to remove all Scalar Properties from the Entity (since it inherits the properties from Reservation and filters based on ReservationDate field) =================================================================== Complex Types (Complex Properties) Entities in EF can also contain Complex Properties (in addition to Scalar Properties) and these Complex Properties reference a ComplexType (not a EntityType) DropdownList, ListBox, RadioButtonList, CheckboxList, Bulletedlist are examples of List server controls (not data bound controls) these controls cannot use Complex properties during databinding, they need Scalar Properties. So if a Entity contains Complex properties and you need to bind those to list server controls then use projections to return Scalar properties and bind them to the control (the disadvantage is that projected collections are not tracked by the Object Context and hence cannot persist changes to the projected collections bound to controls) ObjectDataSource and EntityDataSource do account for Complex properties and one can bind entities with Complex Properties to Data Source controls and they will be tracked for changes... with no additional plumbing needed to persist changes to these collections bound to controls So DataBound controls like GridView, FormView need to use EntityDataSource or ObjectDataSource as a datasource for entities that contain Complex properties so that changes to the datasource done using the GridView can be persisted to the DB (enabling the controls for updates)....if you cannot use the EntityDataSource you need to flatten the ComplexType Properties using projections With EF Version 4 ComplexTypes are supported by the Designer and can add/remove/compose Complex Types directly using the Designer =================================================================== Conditional Mapping ... is like Table per Hierarchy Inheritance where Entities inherit from a base class and then used conditions to populate the EntitySet (called conditional Mapping). Conditional Mapping has limitations since you can only use =, is null and IS NOT NULL Conditions to do conditional mapping. If you need more operators for filtering/mapping conditionally then use QueryView(or possibly Defining Query) to create a readonly entity. QueryView are readonly by default... the EntitySet created by the QueryView is enabled for change tracking by the ObjectContext, however the ObjectContext cannot create insert/update/delete TSQL statements for these Entities when SaveChanges is called since it is QueryView. One way to get around this limitation is to map stored procedures for the insert/update/delete operations in the Designer. =================================================================== Difference between QueryView and Defining Query : QueryView is defined in the (MSL) Mapping File/section of the EDM XML, whereas the DefiningQuery is defined in the store schema (SSDL). QueryView is written using Entity SQL and is this database agnostic and can be used against any database/Data Layer. DefiningQuery is written using Database Lanaguage i.e. TSQL or PSQL thus you have more control =================================================================== Performance: Lazy loading is deferred loading done automatically. lazy loading is supported with EF version4 and is on by default. If you need to turn it off then use context.ContextOptions.lazyLoadingEnabled = false To improve Performance consider PreCompiling the ObjectQuery using the CompiledQuery.Compile method

  Read the article

• Need help with PHP web app bootstrapping error potentially related to Zend [migrated]

  - by Matt Shepherd

  I am trying to get a program called OpenFISMA running on an Ubuntu AMI in AWS. The app is not really coded on the Ubuntu platform, but I am in my comfort zone there, and have tried both CentOS and OpenSUSE (both are sort of "native" for the app) for getting it working with the same or worse results. So, why not just get it working on Ubuntu? Anyway, the app is found here: www.openfisma.org and an install guide is found here: https://openfisma.atlassian.net/wiki/display/030100/Installation+Guide The install guide kind of sucks. It doesn't list dependencies in any coherent way or provide much of any detail (does not even mention Zend once on the entire page) so I've done a lot of work to divine the information I do have. This page provided some dependency inf (though again, Zend is not mentioned once): https://openfisma.atlassian.net/wiki/display/PUBLIC/RPM+Management#RPMManagement-BasicOverviewofRPMPackages Anyway, I got all the way through the install (so far as I could reconstruct it). I am going to the login page for the first time, and there should be some sort of bootstrapping occurring when I load the page. (I am not a programmer so I have no idea what it is doing there.) Anyway, I get a message on the web page that says: "An exception occurred while bootstrapping the application." So, then I go look in /var/www/data/logs/php.log and find this message: [22-Oct-2013 17:29:18 UTC] PHP Fatal error: Uncaught exception 'Zend_Exception' with message 'No entry is registered for key 'Zend_Log'' in /var/www/library/Zend/Registry.php:147 Stack trace: #0 /var/www/public/index.php(188): Zend_Registry::get('Zend_Log') #1 {main} thrown in /var/www/library/Zend/Registry.php on line 147 This occurs every time I load the page. I gather there is an issue related to registering the Zend_Log variable in the Zend registry, but other than that I really have no idea what to do about it. Am I missing a package that it needs, or is this app not coded to register the variables properly? I have no clue. Any help is greatly appreciated. The application file referenced in the log message (index.php) is included below. <?php /** * Copyright (c) 2008 Endeavor Systems, Inc. * * This file is part of OpenFISMA. * * OpenFISMA is free software: you can redistribute it and/or modify it under the terms of the GNU General Public * License as published by the Free Software Foundation, either version 3 of the License, or (at your option) any later * version. * * OpenFISMA is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without even the implied * warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for more * details. * * You should have received a copy of the GNU General Public License along with OpenFISMA. If not, see * {@link http://www.gnu.org/licenses/}. */ try { defined('APPLICATION_PATH') || define( 'APPLICATION_PATH', realpath(dirname(__FILE__) . '/../application') ); // Define application environment defined('APPLICATION_ENV') || define( 'APPLICATION_ENV', (getenv('APPLICATION_ENV') ? getenv('APPLICATION_ENV') : 'production') ); set_include_path( APPLICATION_PATH . '/../library/Symfony/Components' . PATH_SEPARATOR . APPLICATION_PATH . '/../library' . PATH_SEPARATOR . get_include_path() ); require_once 'Fisma.php'; require_once 'Zend/Application.php'; $application = new Zend_Application( APPLICATION_ENV, APPLICATION_PATH . '/config/application.ini' ); Fisma::setAppConfig($application->getOptions()); Fisma::initialize(Fisma::RUN_MODE_WEB_APP); $application->bootstrap()->run(); } catch (Zend_Config_Exception $zce) { // A zend config exception indicates that the application may not be installed properly echo '<h1>The application is not installed correctly</h1>'; $zceMsg = $zce->getMessage(); if (stristr($zceMsg, 'parse_ini_file') !== false) { if (stristr($zceMsg, 'application.ini') !== false) { if (stristr($zceMsg, 'No such file or directory') !== false) { echo 'The ' . APPLICATION_PATH . '/config/application.ini file is missing.'; } elseif (stristr($zceMsg, 'Permission denied') !== false) { echo 'The ' . APPLICATION_PATH . '/config/application.ini file does not have the ' . 'appropriate permissions set for the application to read it.'; } else { echo 'An ini-parsing error has occured in ' . APPLICATION_PATH . '/config/application.ini ' . '<br/>Please check this file and make sure everything is setup correctly.'; } } else if (stristr($zceMsg, 'database.ini') !== false) { if (stristr($zceMsg, 'No such file or directory') !== false) { echo 'The ' . APPLICATION_PATH . '/config/database.ini file is missing.<br/>'; echo 'If you find a database.ini.template file in the config directory, edit this file ' . 'appropriately and rename it to database.ini'; } elseif (stristr($zceMsg, 'Permission denied') !== false) { echo 'The ' . APPLICATION_PATH . '/config/database.ini file does not have the appropriate ' . 'permissions set for the application to read it.'; } else { echo 'An ini-parsing error has occured in ' . APPLICATION_PATH . '/config/database.ini ' . '<br/>Please check this file and make sure everything is setup correctly.'; } } else { echo 'An ini-parsing error has occured. <br/>Please check all configuration files and make sure ' . 'everything is setup correctly'; } } elseif (stristr($zceMsg, 'syntax error') !== false) { if (stristr($zceMsg, 'application.ini') !== false) { echo 'There is a syntax error in ' . APPLICATION_PATH . '/config/application.ini ' . '<br/>Please check this file and make sure everything is setup correctly.'; } elseif (stristr($zceMsg, 'database.ini') !== false) { echo 'There is a syntax error in ' . APPLICATION_PATH . '/config/database.ini ' . '<br/>Please check this file and make sure everything is setup correctly.'; } else { echo 'A syntax error has been reached. <br/>Please check all configuration files and make sure ' . 'everything is setup correctly.'; } } else { // Then the exception message says nothing about parse_ini_file nor 'syntax error' echo 'Please check all configuration files, and ensure all settings are valid.'; } echo '<br/>For more information and help on installing OpenFISMA, please refer to the ' . '<a target="_blank" href="http://manual.openfisma.org/display/ADMIN/Installation">' . 'Installation Guide</a>'; } catch (Doctrine_Manager_Exception $dme) { echo '<h1>An exception occurred while bootstrapping the application.</h1>'; // Does database.ini have valid settings? Or is it the same content as database.ini.template? $databaseIniFail = false; $iniData = file(APPLICATION_PATH . '/config/database.ini'); $iniData = str_replace(chr(10), '', $iniData); if (in_array('db.adapter = ##DB_ADAPTER##', $iniData)) { $databaseIniFail = true; } if (in_array('db.host = ##DB_HOST##', $iniData)) { $databaseIniFail = true; } if (in_array('db.port = ##DB_PORT##', $iniData)) { $databaseIniFail = true; } if (in_array('db.username = ##DB_USER##', $iniData)) { $databaseIniFail = true; } if (in_array('db.password = ##DB_PASS##', $iniData)) { $databaseIniFail = true; } if (in_array('db.schema = ##DB_NAME##', $iniData)) { $databaseIniFail = true; } if ($databaseIniFail) { echo 'You have not applied the settings in ' . APPLICATION_PATH . '/config/database.ini appropriately. ' . 'Please review the contents of this file and try again.'; } else { if (Fisma::debug()) { echo '<p>' . get_class($dme) . '</p><p>' . $dme->getMessage() . '</p><p>' . "<p><pre>Stack Trace:\n" . $dme->getTraceAsString() . '</pre></p>'; } else { $logString = get_class($dme) . "\n" . $dme->getMessage() . "\nStack Trace:\n" . $dme->getTraceAsString() . "\n"; Zend_Registry::get('Zend_Log')->err($logString); } } } catch (Exception $exception) { // If a bootstrap exception occurs, that indicates a serious problem, such as a syntax error. // We won't be able to do anything except display an error. echo '<h1>An exception occurred while bootstrapping the application.</h1>'; if (Fisma::debug()) { echo '<p>' . get_class($exception) . '</p><p>' . $exception->getMessage() . '</p><p>' . "<p><pre>Stack Trace:\n" . $exception->getTraceAsString() . '</pre></p>'; } else { $logString = get_class($exception) . "\n" . $exception->getMessage() . "\nStack Trace:\n" . $exception->getTraceAsString() . "\n"; Zend_Registry::get('Zend_Log')->err($logString); } }

  Read the article

• OOW 2013 Summary for Fusion Middleware Architects & Administrators by Simon Haslam

  - by JuergenKress

  OOW 2013 Summary for Fusion Middleware Architects & Administrators by Simon Haslam This September during Oracle OpenWorld 2013 the weather in San Francisco, as you see can from the photo, was exceptionally sunny. The dramatic final few days of the Americas Cup sailing competition, being held every day in the bay, coincided with the conference and meant that there was almost a holiday feel to the whole event. Here's my annual round-up of what I think was most interesting at OpenWorld 2013 for Fusion Middleware architects and administrators; I hope you find it useful and if you think I've missed something please add a comment! WebLogic and Cloud Application Foundation (CAF) The big WebLogic release of the year has already happened a few months ago with 12.1.2 so I won't duplicate that here. Will Lyons discussed the WebLogic and Coherence roadmap which essentially is that 12.1.3 will probably be released to coincide with SOA 12c next year and that 12.1.4, the next feature-rich WebLogic release, is more likely to be in 2015. This latter release will probably include full Java EE 7 support, have enhancements for multi-tenancy and further auto-scaling features to support increased density (i.e. more WebLogic usage for the same amount of hardware). There's a new Oracle Virtual Assembly Builder (OVAB) out already and an Oracle Traffic Director (OTD) 12c release round the corner too. Also of relevance to administrators is that Oracle has increased the support lifetime for Fusion Middleware 11g (e.g. WebLogic 10.3.6) so that Premier Support will now run to the end of 2018 and Extended Support until 2021 - this should remove any Oracle-driven pressure to upgrade at least. Java Mission Control Java Mission Control (JMC) is the HotSpot Java 7 version of JRockit 6 Mission Control, a very nice performance monitoring tool from Oracle's BEA acquisition. Flight Recorder is a feature built into the JVM which records diagnostic events into, typically, a circular buffer which can then be used for historical analysis, particularly in the case of a JVM crash or hang. It's been available separately for WebLogic only for perhaps a year now but, more significantly, it now includes JVM events and was bundled in with JDK7 Update 40 a few weeks ago. I attended a couple of interesting Java One sessions on JMC/Flight Recorder and have to say it's looking really good - it has all the previous JRMC features except for memory leak detector, plus some enhancements around operative sets and ECID filtering I think. Marcus also showed how you could add your own events into flight recorder by building your own event class - they are then available for graphing alongside all the other events in JMC. This uses a currently an unsupported/undocumented API, but it's also the same one that WebLogic uses for WLDF events so I imagine it is stable. I'm not sure quite whether this would be useful to custom applications, as opposed to infrastructure services or ISV packaged applications, but it was a very nice demonstration. I've been testing JMC / FR enabling on several environments recently and my confidence is growing - it feels robust and I think could very soon be part of my standard builds. Read the full article here. WebLogic Partner Community For regular information become a member in the WebLogic Partner Community please visit: http://www.oracle.com/partners/goto/wls-emea ( OPN account required). If you need support with your account please contact the Oracle Partner Business Center. Blog Twitter LinkedIn Mix Forum Wiki Technorati Tags: OOW,Simon Haslam,Oracle OpenWorld,WebLogic,WebLogic Community,Oracle,OPN,Jürgen Kress

  Read the article

• Entity Framework &amp; Transactions

  - by Sudheer Kumar

  There are many instances we might have to use transactions to maintain data consistency. With Entity Framework, it is a little different conceptually. Case 1 – Transaction b/w multiple SaveChanges(): here if you just use a transaction scope, then Entity Framework (EF) will use distributed transactions instead of local transactions. The reason is that, EF closes and opens the connection when ever required only, which means, it used 2 different connections for different SaveChanges() calls. To resolve this, use the following method. Here we are opening a connection explicitly so as not to span across multipel connections.   using (TransactionScope ts = new TransactionScope()) {     context.Connection.Open();     //Operation1 : context.SaveChanges();     //Operation2 :  context.SaveChanges()     //At the end close the connection     ts.Complete(); } catch (Exception ex) {       //Handle Exception } finally {       if (context.Connection.State == ConnectionState.Open)       {            context.Connection.Close();       } }   Case 2 – Transaction between DB & Non-DB operations: For example, assume that you have a table that keeps track of Emails to be sent. Here you want to update certain details like DataSent once if the mail was successfully sent by the e-mail client. Email eml = GetEmailToSend(); eml.DateSent = DateTime.Now; using (TransactionScope ts = new TransactionScope()) {    //Update DB    context.saveChanges();   //if update is successful, send the email using smtp client   smtpClient.Send();   //if send was successful, then commit   ts.Complete(); }   Here since you are dealing with a single context.SaveChanges(), you just need to use the TransactionScope, just before saving the context only.   Hope this was helpful!

  Read the article

• Using Managed Beans with your ADF Mobile Client Applications

  - by [email protected]

  Did you know it's easy to extend your ADF Mobile Client application with a Managed Bean just like it is with an ADF web application?  Here's how: Using the New Gallery (File -> New), create a new Java class.  This class should extend oracle.adfnmc.el.utils.BeanResolver.         Add this java class as a managed bean: Go to your task flow, select the Overview tab at the bottom and go to the Managed Bean section.  Add an entry and name your new Managed Bean and point to the java class you just created.        Add your custom methods and properties to your java class   Since reflection is not supported in the J2ME version on some platforms (BlackBerry), you need to provide dispatch code if you want to invoke/access any of your methods/properties from EL.  Here's a sample:  MyBeanClass.java    Use Expression Language (EL) to access your properties and invoke your methods on your MCX pages.  Here's an sample:     <?xml version="1.0" encoding="UTF-8" ?><amc:view xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"          xmlns:amc="http://xmlns.oracle.com/jdev/amc">  <amc:form id="form0">    <amc:menuControl refId="menu0"/>    <amc:panelGroupLayout id="panelGroupLayout1" width="100%">      <amc:panelGroupLayout id="panelGroupLayout2" layout="horizontal"                            width="100%">        <amc:image id="image1" source="logo_sm.png"/>        <amc:outputText value="Home" id="outputText1" verticalAlign="center"                        fontSize="20" fontWeight="bold"                        foregroundColor="#ff0000"/>      </amc:panelGroupLayout>      <amc:commandLink text="#{MyBean.property1}" id="commandLink1"                       actionListener="#{MyBean.doFoo}"                       foregroundColor="#0000ff" action="patientlist"/>    </amc:panelGroupLayout>  </amc:form>  <amc:menu type="main" id="menu0">    <amc:menuGroup id="menuGroup1">      <amc:commandMenuItem id="commandMenuItem1" action="exit" label="Exit"                           index="1" weight="0"/>    </amc:menuGroup>  </amc:menu></amc:view> 

  Read the article

• Web workflow solution - how should I approach the design?

  - by Tom Pickles

  We've been tasked with creating a web based workflow tool to track change management. It has a single workflow with multiple synchronous tasks for the most part, but branch out at a point to tasks running in parallel which meet up later on. There will be all sorts of people using the application, and all of them will need to see their outstanding tasks for each change, but only theirs, not others. There will also be a high level group of people who oversee all changes, so need to see everything. They will need to see tasks which have not been done in the specified time, who's responsible etc. The data will be persisted to a SQL database. It'll all be put together using .Net. I've been trying to learn and implement OOP into my designs of late, but I'm wondering if this is moot in this instance as it may be better to have the business logic for this in stored procedures in the DB. I could use POCO's, a front end layer and a data access layer for the web application and just use it as a mechanism for CRUD actions on the DB, then use SP's fired in the DB to apply the business rules. On the other hand, I could use an object oriented design within the web app, but as the data in the app is state-less, is this a bad idea? I could try and model out the whole application into a class structure, implementing interfaces, base classes and all that good stuff. So I would create a change class, which contained a list of task classes/types, which defined each task, and implement an ITask interface etc. Put end-user types into the tasks to identify who should be doing what task. Then apply all the business logic in the respective class methods etc. What approach do you guys think I should be using for this solution?

  Read the article

• Change Data Capture

  - by Ricardo Peres

  There's an hidden gem in SQL Server 2008: Change Data Capture (CDC). Using CDC we get full audit capabilities with absolutely no implementation code: we can see all changes made to a specific table, including the old and new values! You can only use CDC in SQL Server 2008 Standard or Enterprise, Express edition is not supported. Here are the steps you need to take, just remember SQL Agent must be running: use SomeDatabase; -- first create a table CREATE TABLE Author ( ID INT NOT NULL PRIMARY KEY IDENTITY(1, 1), Name NVARCHAR(20) NOT NULL, EMail NVARCHAR(50) NOT NULL, Birthday DATE NOT NULL ) -- enable CDC at the DB level EXEC sys.sp_cdc_enable_db -- check CDC is enabled for the current DB SELECT name, is_cdc_enabled FROM sys.databases WHERE name = 'SomeDatabase' -- enable CDC for table Author, all columns exec sys.sp_cdc_enable_table @source_schema = 'dbo', @source_name = 'Author', @role_name = null -- insert values into table Author insert into Author (Name, EMail, Birthday, Username) values ('Bla', 'bla@bla', 1990-10-10, 'bla') -- check CDC data for table Author -- __$operation: 1 = DELETE, 2 = INSERT, 3 = BEFORE UPDATE 4 = AFTER UPDATE -- __$start_lsn: operation timestamp select * from cdc.dbo_author_CT -- update table Author update Author set EMail = '[email protected]' where Name = 'Bla' -- check CDC data for table Author select * from cdc.dbo_author_CT -- delete from table Author delete from Author -- check CDC data for table Author select * from cdc.dbo_author_CT -- disable CDC for table Author -- this removes all CDC data, so be carefull exec sys.sp_cdc_disable_table @source_schema = 'dbo', @source_name = 'Author', @capture_instance = 'dbo_Author' -- disable CDC for the entire DB -- this removes all CDC data, so be carefull exec sys.sp_cdc_disable_db SyntaxHighlighter.config.clipboardSwf = 'http://alexgorbatchev.com/pub/sh/2.0.320/scripts/clipboard.swf'; SyntaxHighlighter.all();

  Read the article

• links for 2010-12-08

  - by Bob Rhubart

  What's a data architect? A comic dialog by one who knows: Oracle ACE Director Lewis Cunningham. Webcast: Oracle Business Intelligence Forum - December 15, 2010 at 9:00 am PT "The Oracle Business Intelligence Online Forum is a half-day virtual event that offers you a unique opportunity to see, in one place, the full portfolio of Oracle’s Business Intelligence (BI) offerings, and to learn what sets Oracle apart from the rest. Hear Oracle executives and industry analyst, Howard Dresner, present the current state of Business Intelligence, along with a series of customers who will share their case studies of putting analytics in action." Oracle Rolls Out Private Cloud Architecture And World-Record Transaction Performance | Forrester Blogs "Exadata has been dealt with extensively in other venues, both inside Forrester and externally, and appears to deliver the goods for I&O groups who require efficient consolidation and maximum performance from an Oracle database environment." -- Richard Fichera, Forrester Seven ways to get things started: Java EE Startup Classes with GlassFish and WebLogic "This is a blog about a topic that I realy don't like. But it comes across my ways over and over again and it's no doubt that you need it from time to time. Enough reasons for me to collect some information about it and publish it for your reference. I am talking about Startup-/Shutdown classes with Java EE applications or servers." -- Oracle ACE Director Markus "@myfear" Eisele." Monitoring Undelivered Messages in BPEL in SOA 10g (Antony Reynolds' Blog) "I am currently working with a client that wants to know how many undelivered messages they have, and if it reaches a certain threshold then they wants to alert the operator. To do this they plan on using the Enterprise Manager alert functions, but first they needs to know how many undelivered instances are out there." SOA author Antony Reynolds VirtualBox Appliances for Developers "Developers can simply download a few files, assemble them with a script , and then import and run the resulting pre-built VM in VirtualBox. This makes starting with these technologies even easier. Each appliance contains some Hands-On-Labs to start learning." -- Peter Paul van de Beek Oracle UCM 11g Remote Intradoc Client (RIDC) Integration with Oracle ADF 11g "It's great we have out of the box WebCenter ADF task flows for document management in UCM. However, for complete business scenario implementations, usually it's not enough and we need to manage Content Repository programmatically. This can be achieved through Remote Intradoc Client (RIDC) API. It's quite hard to find any practical information about this API, but I managed to get code for UCM folder creation/removal and folder information." -- Oracle ACE Director Andrejus Baranovskis Interview with Java Champion Matjaz B. Juric on Cloud Computing, SOA, and Java EE 6 "Matjaz Juric of Slovenia, head of the Cloud Computing and SOA Competence Centre at the University of Maribor, and professor at the University of Ljubljana, shares insights about cloud computing, SOA and Java EE 6." White Paper: Oracle Complex Event Processing High Availability "This whitepaper describes the high availability (HA) solutions available in Oracle CEP 11g Release 1 Patch Set 2 and  presents the results of a benchmark study demonstrating the performance of the Oracle CEP HA solutions."

  Read the article

• Is this kind of design - a class for Operations On Object - correct?

  - by Mithir

  In our system we have many complex operations which involve many validations and DB activities. One of the main Business functionality could have been designed better. In short, there were no separation of layers, and the code would only work from the scenario in which it was first designed at, and now there were more scenarios (like requests from an API or from other devices) So I had to redesign. I found myself moving all the DB code to objects which acts like Business to DB objects, and I've put all the business logic in an Operator kind of a class, which I've implemented like this: First, I created an object which will hold all the information needed for the operation let's call it InformationObject. Then I created an OperatorObject which will take the InformationObject as a parameter and act on it. The OperatorObject should activate different objects and validate or check for existence or any scenario in which the business logic is compromised and then make the operation according to the information on the InformationObject. So my question is - Is this kind of implementation correct? PS, this Operator only works on a single Business-wise Operation.

  Read the article

• What is up with the Joy of Clojure 2nd edition?

  - by kurofune

  Manning just released the second edition of the beloved Joy of Clojure book, and while I share that love I get the feeling that many of the examples are already outdated. In particular, in the chapter on optimization the recommended type-hinting seems not to be allowed by the compiler. I don't know if this was allowable for older versions of Clojure. For example: (defn factorial-f [^long original-x] (loop [x original-x, acc 1] (if (>= 1 x) acc (recur (dec x) (*' x acc))))) returns: clojure.lang.Compiler$CompilerException: java.lang.UnsupportedOperationException: Can't type hint a primitive local, compiling:(null:3:1) Likewise, the chapter on core.logic seems be using an old API and I have to find workarounds for each example to accommodate the recent changes. For example, I had to turn this: (logic/defrel orbits orbital body) (logic/fact orbits :mercury :sun) (logic/fact orbits :venus :sun) (logic/fact orbits :earth :sun) (logic/fact orbits :mars :sun) (logic/fact orbits :jupiter :sun) (logic/fact orbits :saturn :sun) (logic/fact orbits :uranus :sun) (logic/fact orbits :neptune :sun) (logic/run* [q] (logic/fresh [orbital body] (orbits orbital body) (logic/== q orbital))) into this, leveraging the pldb lib: (pldb/db-rel orbits orbital body) (def facts (pldb/db [orbits :mercury :sun] [orbits :venus :sun] [orbits :earth :sun] [orbits :mars :sun] [orbits :jupiter :sun] [orbits :saturn :sun] [orbits :uranus :sun] [orbits :neptune :sun])) (pldb/with-db facts (logic/run* [q] (logic/fresh [orbital body] (orbits orbital body) (logic/== q orbital)))) I am still pulling teeth to get the later examples to work. I am relatively new programming, myself, so I wonder if I am naively looking over something here, or are if these points I'm making legitimate concerns? I really want to get good at this stuff like type-hinting and core.logic, but wanna make sure I am studying up to date materials. Any illuminating facts to help clear up my confusion would be most welcome.

  Read the article

• ArchBeat Facebook Friday: Top 10 Shared Links - May 30- June 5, 2014

  - by OTN ArchBeat

  The list below is comprised of the Top 10 most popular articles, blog posts, videos, and other content shared over the last seven days with the more than 5,100 people fans of the OTN ArchBeat Facebook Page. What is REST? | Maarten Smeets "Most Middleware developers will encounter RESTful services," says Oracle SOA / BPM / Java integration specialist Maarten Smeets. "It is good to understand what they are, what they should be and how they work." His extensive post will help you achieve that understanding. Integrating with Fusion Applications using SOAP web services and REST APIs | Arvind Srinivasamoorth This article, part one of Arvind Srinivasamoorth's two-part series on Integrating with Fusion Applications using SOAP web services and REST APIs, shows you how to identify the Fusion Applications SOAP web service to be invoked. Oracle Technology Network | Architect Community Have you visited the OTN Solution Architect homepage lately? I've just updated it with information about the big OTN Virtual Tech Summit on July 9, plus the latest OTN tech articles, and a fresh list of community videos and podcasts. Check it out! Starting and Stopping a Java EE Environment when using Oracle WebLogic | Rene van Wijk Oracle ACE Director and Oracle Fusion Middleware specialist Rene van Wijk explores ways to simplify the life-cycle management of a Java EE environment through the use of scripts developed with WebLogic Scripting Tool and Linux Bash. Application Composer Series: Where and When to use Groovy | Richard Bingham Richard Bingham describes his post as "more of a reference than an article." The post is comprised of a table that highlights where you can add your own custom logic via Groovy code and when you might use the various features. Kscope 2014: HFM Metadata Diagnostics | Eric Erikson Oracle Certified Hyperion Financial Management Specialist Eric Erikson will present three sessions at ODTUG Kscope 2014, June 22-26 in Seattle. Why should you care? Watch the video. Tuning Asynchronous Web Services in Fusion Applications | Jian Liang This article, the fourth in solution architect Jian Liang's five-part series on Fusion Applications and asynchronous Web Services, shows you how to conduct performance tuning of the asynchronous web services in relation to Fusion Applications. IDM FA Integration Flows | Thiago Leoncio Fusion Applications uses the Oracle Identity Management for its identity store and policy store by default. This article by solution architect Thiago Leoncio explains how user and role flows work from different points of view, using key IDM products for each flow in detail. GoldenGate and Oracle Data Integrator - A Perfect Match in 12c... Part 1: Getting Started | Michael Rainey Michael Rainey has already written extensively about about integration between Oracle Data Integrator and GoldenGate -- but he's not done. "With the release of the 12c versions of ODI and GoldenGate last October, and a soon-to-be-updated reference architecture, it’s time to write a few posts on the subject again, " he says. Here's the first of those posts. Video: Kscope 2014 Preview: Tim Tow on Essbase Java API and ODTUG Community Oracle ACE Director and ODTUG board member Tim Tow talks about his Kscope 2014 sessions focused on the Essbase Java API in this short video interview.

  Read the article

• SQL analytical mash-ups deliver real-time WOW! for big data

  - by KLaker

  One of the overlooked capabilities of SQL as an analysis engine, because we all just take it for granted, is that you can mix and match analytical features to create some amazing mash-ups. As we move into the exciting world of big data these mash-ups can really deliver those "wow, I never knew that" moments. While Java is an incredibly flexible and powerful framework for managing big data there are some significant challenges in using Java and MapReduce to drive your analysis to create these "wow" discoveries. One of these "wow" moments was demonstrated at this year's OpenWorld during Andy Mendelsohn's general keynote session.  Here is the scenario - we are looking for fraudulent activities in our big data stream and in this case we identifying potentially fraudulent activities by looking for specific patterns. We using geospatial tagging of each transaction so we can create a real-time fraud-map for our business users. Where we start to move towards a "wow" moment is to extend this basic use of spatial and pattern matching, as shown in the above dashboard screen, to incorporate spatial analytics within the SQL pattern matching clause. This will allow us to compute the distance between transactions. Apologies for the quality of this screenshot….hopefully below you see where we have extended our SQL pattern matching clause to use location of each transaction and to calculate the distance between each transaction: This allows us to compare the time of the last transaction with the time of the current transaction and see if the distance between the two points is possible given the time frame. Obviously if I buy something in Florida from my favourite bike store (may be a new carbon saddle for my Trek) and then 5 minutes later the system sees my credit card details being used in Arizona there is high probability that this transaction in Arizona is actually fraudulent (I am fast on my Trek but not that fast!) and we can flag this up in real-time on our dashboard: In this post I have used the term "real-time" a couple of times and this is an important point and one of the key reasons why SQL really is the only language to use if you want to analyse  big data. One of the most important questions that comes up in every big data project is: how do we do analysis? Many enlightened customers are now realising that using Java-MapReduce to deliver analysis does not result in "wow" moments. These "wow" moments only come with SQL because it is offers a much richer environment, it is simpler to use and it is faster - which makes it possible to deliver real-time "Wow!". Below is a slide from Andy's session showing the results of a comparison of Java-MapReduce vs. SQL pattern matching to deliver our "wow" moment during our live demo.  You can watch our analytical mash-up "Wow" demo that compares the power of 12c SQL pattern matching + spatial analytics vs. Java-MapReduce  here: You can get more information about SQL Pattern Matching on our SQL Analytics home page on OTN, see here http://www.oracle.com/technetwork/database/bi-datawarehousing/sql-analytics-index-1984365.html.  You can get more information about our spatial analytics here: http://www.oracle.com/technetwork/database-options/spatialandgraph/overview/index.html If you would like to watch the full Database 12c OOW presentation see here: http://medianetwork.oracle.com/video/player/2686974264001

  Read the article

• Mind Reading with the Raspberry Pi

  - by speakjava

  Mind Reading With The Raspberry Pi At JavaOne in San Francisco I did a session entitled "Do You Like Coffee with Your Dessert? Java and the Raspberry Pi".  As part of this I showed some demonstrations of things I'd done using Java on the Raspberry Pi.  This is the first part of a series of blog entries that will cover all the different aspects of these demonstrations. A while ago I had bought a MindWave headset from Neurosky.  I was particularly interested to see how this worked as I had had the opportunity to visit Neurosky several years ago when they were still developing this technology.  At that time the 'headset' consisted of a headband (very much in the Bjorn Borg style) with a sensor attached and some wiring that clearly wasn't quite production ready.  The commercial version is very simple and easy to use: there are two sensors, one which rests on the skin of your forehead, the other is a small clip that attaches to your earlobe. Typical EEG sensors used in hospitals require lots of sensors and they all need copious amounts of conductive gel to ensure the electrical signals are picked up.  Part of Neurosky's innovation is the development of this simple dry-sensor technology.  Having put on the sensor and turned it on (it powers off a single AAA size battery) it collects data and transmits it to a USB dongle plugged into a PC, or in my case a Raspberry Pi. From a hacking perspective the USB dongle is ideal because it does not require any special drivers for any complex, low level USB communication.  Instead it appears as a simple serial device, which on the Raspberry Pi is accessed as /dev/ttyUSB0.  Neurosky have published details of the command protocol.  In addition, the MindSet protocol document, including sample code for parsing the data from the headset, can be found here. To get everything working on the Raspberry Pi using Java the first thing was to get serial communications going.  Back in the dim distant past there was the Java Comm API.  Sadly this has grown a bit dusty over the years, but there is a more modern open source project that provides compatible and enhanced functionality, RXTXComm.  This can be installed easily on the Pi using sudo apt-get install librxtx-java.  Next I wrote a library that would send commands to the MindWave headset via the serial port dongle and read back data being sent from the headset.  The design is pretty simple, I used an event based system so that code using the library could register listeners for different types of events from the headset.  You can download a complete NetBeans project for this here.  This includes javadoc API documentation that should make it obvious how to use it (incidentally, this will work on platforms other than Linux.  I've tested it on Windows without any issues, just by changing the device name to something like COM4). To test this I wrote a simple application that would connect to the headset and then print the attention and meditation values as they were received from the headset.  Again, you can download the NetBeans project for that here. Oracle recently released a developer preview of JavaFX on ARM which will run on the Raspberry Pi.  I thought it would be cool to write a graphical front end for the MindWave data that could take advantage of the built in charts of JavaFX.  Yet another NetBeans project is available here.  Screen shots of the app, which uses a very nice dial from the JFxtras project, are shown below. I probably should add labels for the EEG data so the user knows which is the low alpha, mid gamma waves and so on.  Given that I'm not a neurologist I suspect that it won't increase my understanding of what the (rather random looking) traces mean. In the next blog I'll explain how I connected a LEGO motor to the GPIO pins on the Raspberry Pi and then used my mind to control the motor!

  Read the article

• JPedal Action for Converting PDF to JavaFX

  - by Geertjan

  The question of the day comes from Mark Stephens, from JPedal (JPedal is the leading 100% Java PDF library, providing a Java PDF viewer, PDF to image conversion, PDF printing or adding PDF search and PDF extraction features), in the form of a screenshot: The question is clear. By looking at the annotations above, you can see that Mark has an ActionListener that has been bound to the right-click popup menu on PDF files. Now he needs to get hold of the file to which the Action has been bound. How, oh  how, can one get hold of that file? Well, it's simple. Leave everything you see above exactly as it is but change the Java code section to this: public final class PDF2JavaFXContext implements ActionListener {     private final DataObject context;     public PDF2JavaFXContext(DataObject context) {         this.context = context;     }     public void actionPerformed(ActionEvent ev) {         FileObject fo = context.getPrimaryFile();         File theFile = FileUtil.toFile(fo);         //do something with your file...     } } The point is that the annotations at the top of the class bind the Action to either Actions.alwaysEnabled, which is a factory method for creating always-enabled Actions, or Actions.context, which is a factory method for creating context-sensitive Actions. How does the Action get bound to the factory method? The annotations are converted, when the module is compiled, into XML registration entries in the "generated-layer.xml", which you can find in your "build" folder, in the Files window, after building the module. In Mark's case, since the Action should be context-sensitive to PDF files, he needs to bind his PDF2JavaFXContext ActionListener (which should probably be named "PDF2JavaFXActionListener", since the class is an ActionListener) to Actions.context. All he needs to do that is pass in the object he wants to work with into the constructor of the ActionListener. Now, when the module is built, the annotation processor is going to take the annotations and convert them to XML registration entries, but the constructor will also be checked to see whether it is empty or not. In this case, the constructor isn't empty, hence the Action should be context-sensitive and so the ActionListener is bound to Actions.context. The Actions.context will do all the enablement work for Mark, so that he will not need to provide any code for enabling/disabling the Action. The Action will be enabled whenever a DataObject is selected. Since his Action is bound to Nodes in the Projects window that represent PDF files, the Action will always be enabled whenever Mark right-clicks on a PDF Node, since the Node exposes its own DataObject. Once Mark has access to the DataObject, he can get the underlying FileObject via getPrimaryFile and he can then convert the FileObject to a java.io.File via FileUtil.getConfigFile. Once he's got the java.io.File, he can do with it whatever he needs. Further reading: http://bits.netbeans.org/dev/javadoc/

  Read the article

• 45 minutes to talk about C# [closed]

  - by Philip

  I have the opportunity to give a 45 minute talk on C# in the theory of programming languages class I'm taking. The college teaches Java almost exclusively, so that's what all the students are most familiar with. (There's a little C, assembly, Prolog and LISP as well.) I decide what to talk about. It seems to me the best approach is to focus on a few of the big, obvious differences between C# and Java. I don't intend it to be a recommendation to use C# -- there are reasons to use each, mostly because of their ecosystems. So I want to focus on C# as a language. I don't want to go too fast and end up listing a whole bunch of features without showing their usefulness. My current plan is this: Functions as first class objects. This is, in my opinion, one of the biggest differences between C# and Java. The professor briefly mentioned this notion and showed a LISP example, but many of the students have probably never used it. I can show real world examples where it's made my code more readable. Lambda expressions as concise syntax for anonymous functions. Obviously with examples to show how this is useful. The real hit-home examples will be at the end when it's combined with the rest. I don't see an advantage to first showing the old delegate syntax and then replacing it with lambdas -- most of us won't have ever seen delegates anyway so it would just be confusing. The yield keyword and how it's different from returning an array. I have the impression that a lot of C# developers aren't familiar with how to use this. It will likely be very foreign to Java developers. I have some examples from my own work where it was really useful, such as iterating over a tree traversal, or iterating over neighbors in a graph where the neighbors aren't stored in memory. In both cases, doing it in Java would likely mean returning a complete list -- with yield I can stop iterating if I find what I want early on, without using memory for superfluous lists or arrays. Extension methods as a way to write implementation on interfaces. We'll all be familiar with how interfaces don't allow method implementation, and how this leads to code duplication. I'll show a specific example of this and how the extension method can solve the problem. Demonstrate how the above can be combined by implementing some simple Linq methods and using them. Where, Select, First, maybe more depending on how much time is left. Ideas on which ones might 'hit home' the best? There are other things I could talk about such as generics, value types, properties and more. I haven't yet though of good ways to incorporate these. In the case of generics and value types, the advantages might not be obvious or as relevant. Properties are obviously useful, particularly since we're taught strict JavaBeans here, but I don't know if I could integrate it with the "path to Linq" discussion above without it feeling tacked on. So I'm looking for thoughts on how to talk about C#, and what to talk about. Even minor details. I'm sure there are more experienced C# developers than me here who have good insight about what's really important in the language, and what would miss the point.

  Read the article

• Visual Basic link to SQL output to Word

  - by CLO_471

  I am in need of some advice/references. I am currently trying to develop a legal document interface. There are certain fields in which I need to query out of my sql db and have those fields output into a document that can be printed. I am trying to develop a user interface where people can enter fields that will output to a document template but at the same time I need the template to be able to pull data from the SQL database. This is the reason why I think that VB might be my best choice and because it is one of the only OOP languages I am familiar with presently. Does anyone know that best way to be able to handle this type of job?? I know that you can use VBA within MS Word and have the form output variables to a word template. But, is there a way to have the word document also pull information from the SQL db? Is the best option to use VB linked to SQL and run queries to get the information from the database and then have it output to a for within VB? Is it possible for VB to be linked to a SQL db and output variables and SQL fields to a Word Template? I have looked into Mail Merge and I see that it allows users to pull data from an Access query but I dont think it would be easy to automate and it seems that users would need to have an advanced knowledge of MS Word and Access to handle this. I am not finding much useful information online so I came here. Any advice or references would be greatly appreciated. If there is a better way please let me know.

  Read the article

• Cannot ping router with a static IP assigned?

  - by Uriah

  Alright. I am running Ubuntu LTS 12.04 and am trying to configure a local caching/master DNS server so I am using Bind9. First, here are some things via default DHCP: /etc/network/interfaces cat /etc/network/interfaces # This file describes the network interfaces available on your system # and how to activate them. For more information, see interfaces(5). # The loopback network interface auto lo iface lo inet loopback # The primary network interface auto eth0 iface eth0 inet dhcp # The primary network interface - STATIC #auto eth0 #iface eth0 inet static # address 192.168.2.113 # netmask 255.255.255.0 # network 192.168.2.0 # broadcast 192.168.2.255 # gateway 192.168.2.1 # dns-search uclemmer.net # dns-nameservers 192.168.2.113 8.8.8.8 /etc/resolv.conf cat /etc/resolv.conf # Dynamic resolv.conf(5) file for glibc resolver(3) generated by resolvconf(8) # DO NOT EDIT THIS FILE BY HAND -- YOUR CHANGES WILL BE OVERWRITTEN nameserver 192.168.2.1 search uclemmer.net ifconfig ifconfig eth0 Link encap:Ethernet HWaddr 00:14:2a:82:d4:9e inet addr:192.168.2.103 Bcast:192.168.2.255 Mask:255.255.255.0 inet6 addr: fe80::214:2aff:fe82:d49e/64 Scope:Link UP BROADCAST RUNNING MULTICAST MTU:1500 Metric:1 RX packets:1067 errors:0 dropped:0 overruns:0 frame:0 TX packets:2504 errors:0 dropped:0 overruns:0 carrier:0 collisions:0 txqueuelen:1000 RX bytes:153833 (153.8 KB) TX bytes:214129 (214.1 KB) Interrupt:23 Base address:0x8800 lo Link encap:Local Loopback inet addr:127.0.0.1 Mask:255.0.0.0 inet6 addr: ::1/128 Scope:Host UP LOOPBACK RUNNING MTU:16436 Metric:1 RX packets:915 errors:0 dropped:0 overruns:0 frame:0 TX packets:915 errors:0 dropped:0 overruns:0 carrier:0 collisions:0 txqueuelen:0 RX bytes:71643 (71.6 KB) TX bytes:71643 (71.6 KB) ping ping -c 4 192.168.2.1 PING 192.168.2.1 (192.168.2.1) 56(84) bytes of data. 64 bytes from 192.168.2.1: icmp_req=1 ttl=64 time=0.368 ms 64 bytes from 192.168.2.1: icmp_req=2 ttl=64 time=0.224 ms 64 bytes from 192.168.2.1: icmp_req=3 ttl=64 time=0.216 ms 64 bytes from 192.168.2.1: icmp_req=4 ttl=64 time=0.237 ms --- 192.168.2.1 ping statistics --- 4 packets transmitted, 4 received, 0% packet loss, time 2997ms rtt min/avg/max/mdev = 0.216/0.261/0.368/0.063 ms ping -c 4 google.com PING google.com (74.125.134.102) 56(84) bytes of data. 64 bytes from www.google-analytics.com (74.125.134.102): icmp_req=1 ttl=48 time=15.1 ms 64 bytes from www.google-analytics.com (74.125.134.102): icmp_req=2 ttl=48 time=11.4 ms 64 bytes from www.google-analytics.com (74.125.134.102): icmp_req=3 ttl=48 time=11.6 ms 64 bytes from www.google-analytics.com (74.125.134.102): icmp_req=4 ttl=48 time=11.5 ms --- google.com ping statistics --- 4 packets transmitted, 4 received, 0% packet loss, time 3003ms rtt min/avg/max/mdev = 11.488/12.465/15.118/1.537 ms ip route ip route default via 192.168.2.1 dev eth0 metric 100 192.168.2.0/24 dev eth0 proto kernel scope link src 192.168.2.103 As you can see, with DHCP everything seems to work fine. Now, here are things with static IP: /etc/network/interfaces cat /etc/network/interfaces # This file describes the network interfaces available on your system # and how to activate them. For more information, see interfaces(5). # The loopback network interface auto lo iface lo inet loopback # The primary network interface #auto eth0 #iface eth0 inet dhcp # The primary network interface - STATIC auto eth0 iface eth0 inet static address 192.168.2.113 netmask 255.255.255.0 network 192.168.2.0 broadcast 192.168.2.255 gateway 192.168.2.1 dns-search uclemmer.net dns-nameservers 192.168.2.1 8.8.8.8 I have tried dns-nameservers in various combos of *.2.1, *.2.113, and other reliable, public nameservers. /etc/resolv.conf cat /etc/resolv.conf # Dynamic resolv.conf(5) file for glibc resolver(3) generated by resolvconf(8) # DO NOT EDIT THIS FILE BY HAND -- YOUR CHANGES WILL BE OVERWRITTEN nameserver 192.168.2.1 nameserver 8.8.8.8 search uclemmer.net Obviously, when I change the nameservers in the /etc/network/interfaces file, the nameservers change here too. ifconfig ifconfig eth0 Link encap:Ethernet HWaddr 00:14:2a:82:d4:9e inet addr:192.168.2.113 Bcast:192.168.2.255 Mask:255.255.255.0 inet6 addr: fe80::214:2aff:fe82:d49e/64 Scope:Link UP BROADCAST RUNNING MULTICAST MTU:1500 Metric:1 RX packets:1707 errors:0 dropped:0 overruns:0 frame:0 TX packets:2906 errors:0 dropped:0 overruns:0 carrier:0 collisions:0 txqueuelen:1000 RX bytes:226230 (226.2 KB) TX bytes:263497 (263.4 KB) Interrupt:23 Base address:0x8800 lo Link encap:Local Loopback inet addr:127.0.0.1 Mask:255.0.0.0 inet6 addr: ::1/128 Scope:Host UP LOOPBACK RUNNING MTU:16436 Metric:1 RX packets:985 errors:0 dropped:0 overruns:0 frame:0 TX packets:985 errors:0 dropped:0 overruns:0 carrier:0 collisions:0 txqueuelen:0 RX bytes:78625 (78.6 KB) TX bytes:78625 (78.6 KB) ping ping -c 4 192.168.2.1 PING 192.168.2.1 (192.168.2.1) 56(84) bytes of data. --- 192.168.2.1 ping statistics --- 4 packets transmitted, 0 received, 100% packet loss, time 3023ms ping -c 4 google.com ping: unknown host google.com Lastly, here are my bind zone files: /etc/bind/named.conf.options cat /etc/bind/named.conf.options options { directory "/etc/bind"; // // // query-source address * port 53; notify-source * port 53; transfer-source * port 53; // If there is a firewall between you and nameservers you want // to talk to, you may need to fix the firewall to allow multiple // ports to talk. See http://www.kb.cert.org/vuls/id/800113 // If your ISP provided one or more IP addresses for stable // nameservers, you probably want to use them as forwarders. // Uncomment the following block, and insert the addresses replacing // the all-0's placeholder. // forwarders { // 0.0.0.0; // }; forwarders { // My local 192.168.2.113; // Comcast 75.75.75.75; 75.75.76.76; // Google 8.8.8.8; 8.8.4.4; // DNSAdvantage 156.154.70.1; 156.154.71.1; // OpenDNS 208.67.222.222; 208.67.220.220; // Norton 198.153.192.1; 198.153.194.1; // Verizon 4.2.2.1; 4.2.2.2; 4.2.2.3; 4.2.2.4; 4.2.2.5; 4.2.2.6; // Scrubit 67.138.54.100; 207.255.209.66; }; // // // //allow-query { localhost; 192.168.2.0/24; }; //allow-transfer { localhost; 192.168.2.113; }; //also-notify { 192.168.2.113; }; //allow-recursion { localhost; 192.168.2.0/24; }; //======================================================================== // If BIND logs error messages about the root key being expired, // you will need to update your keys. See https://www.isc.org/bind-keys //======================================================================== dnssec-validation auto; auth-nxdomain no; # conform to RFC1035 listen-on-v6 { any; }; }; /etc/bind/named.conf.local cat /etc/bind/named.conf.local // // Do any local configuration here // // Consider adding the 1918 zones here, if they are not used in your // organization //include "/etc/bind/zones.rfc1918"; zone "example.com" { type master; file "/etc/bind/zones/db.example.com"; }; zone "2.168.192.in-addr.arpa" { type master; file "/etc/bind/zones/db.2.168.192.in-addr.arpa"; /etc/bind/zones/db.example.com cat /etc/bind/zones/db.example.com ; ; BIND data file for example.com interface ; $TTL 604800 @ IN SOA yossarian.example.com. root.example.com. ( 1343171970 ; Serial 604800 ; Refresh 86400 ; Retry 2419200 ; Expire 604800 ) ; Negative Cache TTL ; @ IN NS yossarian.example.com. @ IN A 192.168.2.113 @ IN AAAA ::1 @ IN MX 10 yossarian.example.com. ; yossarian IN A 192.168.2.113 router IN A 192.168.2.1 printer IN A 192.168.2.200 ; ns01 IN CNAME yossarian.example.com. www IN CNAME yossarian.example.com. ftp IN CNAME yossarian.example.com. ldap IN CNAME yossarian.example.com. mail IN CNAME yossarian.example.com. /etc/bind/zones/db.2.168.192.in-addr.arpa cat /etc/bind/zones/db.2.168.192.in-addr.arpa ; ; BIND reverse data file for 2.168.192.in-addr interface ; $TTL 604800 @ IN SOA yossarian.example.com. root.example.com. ( 1343171970 ; Serial 604800 ; Refresh 86400 ; Retry 2419200 ; Expire 604800 ) ; Negative Cache TTL ; @ IN NS yossarian.example.com. @ IN A 255.255.255.0 ; 113 IN PTR yossarian.example.com. 1 IN PTR router.example.com. 200 IN PTR printer.example.com. ip route ip route default via 192.168.2.1 dev eth0 metric 100 192.168.2.0/24 dev eth0 proto kernel scope link src 192.168.2.113 I can SSH in to the machine locally at *.2.113 or at whatever address is dynamically assigned when in DHCP "mode". *2.113 is in my router's range and I have ports open and forwarding to the server. Pinging is enabled on the router too. I briefly had a static configuration working but it died after the first reboot. Please let me know what other info you might need. I am beyond frustrated/baffled.

  Read the article

• How to mange big amount users at server side?

  - by Rami

  I built a social android application in which users can see other users around them by gps location. at the beginning thing went well as i had low number of users, But now that I have increasing number of users (about 1500 +100 every day) I revealed a major problem in my design. In my Google App Engine servlet I have static HashMap that holding all the users profiles objects, currenty 1500 and this number will increase as more users register. Why I'm doing it Every user that requesting for the users around him compares his gps with other users and check if they are in his 10km radius, this happens every 5 min on average. That is why I can't get the users from db every time because GAE read/write operation quota will tare me apart. The problem with this desgin is As the number of users increased the Hashmap turns to null every 4-6 hours, I thing that this time is getting shorten but I'm not sure. I'm fixing this by reloading the users from the db every time I detect that it became null, But this causes DOS to my users for 30 sec, So I'm looking for better solution. I'm guessing that it happens because the size of the hashmap, Am I right? I have been advised to use spatial database, but that mean that I can't work with GAE any more and that mean that I need to build my big server all over again and lose my existing DB. Is there something I can do with the existing tools? Thanks.

  Read the article

• Fun with Python

  - by dotneteer

  I am taking a class on Coursera recently. My formal education is in physics. Although I have been working as a developer for over 18 years and have learnt a lot of programming on the job, I still would like to gain some systematic knowledge in computer science. Coursera courses taught by Standard professors provided me a wonderful chance. The three languages recommended for assignments are Java, C and Python. I am fluent in Java and have done some projects using C++/MFC/ATL in the past, but I would like to try something different this time. I first started with pure C. Soon I discover that I have to write a lot of code outside the question that I try to solve because the very limited C standard library. For example, to read a list of values from a file, I have to read characters by characters until I hit a delimiter. If I need a list that can grow, I have to create a data structure myself, something that I have taking for granted in .Net or Java. Out of frustration, I switched to Python. I was pleasantly surprised to find that Python is very easy to learn. The tutorial on the official Python site has the exactly the right pace for me, someone with experience in another programming. After a couple of hours on the tutorial and a few more minutes of toying with IDEL, I was in business. I like the “battery supplied” philosophy that gives everything that I need out of box. For someone from C# or Java background, curly braces are replaced by colon(:) and tab spaces. Although I tend to miss colon from time to time, I found that the idea of tab space is actually very nice once I get use to them. I also like to feature of multiple assignment and multiple return parameters. When I need to return a by-product, I just add it to the list of returns. When would use Python? I would use Python if I need to computer anything quick. The language is very easy to use. Python has a good collection of libraries (packages). The REPL of the interpreter allows me test ideas quickly before committing them into script. Lots of computer science work have been ported from Lisp to Python. Some universities are even teaching SICP in Python. When wouldn’t I use Python? I mostly would not use it in a managed environment, such as Ironpython or Jython. Both .Net and Java already have a rich library so one has to make a choice which library to use. If we use the managed runtime library, the code will tie to the particular runtime and thus not portable. If we use the Python library, then we will face the relatively long start-up time. For this reason, I would not recommend to use Ironpython for WP7 development. The only situation that I see merit with managed Python is in a server application where I can preload Python so that the start-up time is not a concern. Using Python as a managed glue language is an over-kill most of the time. A managed Scheme could be a better glue language as it is small enough to start-up very fast.

  Read the article

< Previous Page | 1080 1081 1082 1083 1084 1085 1086 1087 1088 1089 1090 1091  | Next Page >