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• Missing Indexes DMV Report, 3 billion Impact!

  - by Tara Kizer

  We’ve been having some major performance issues with one of the applications that I support.  The database is on SQL Server 2005 and is about 150GB in size.  We’ve identified a couple of issues already on the database side.  The first issue is that some query (or maybe several queries) is getting a bad execution plan at some point in time during the day.  When it occurs, database performance comes to a grinding halt.  We know it’s a bad execution plan as running DBCC FREEPROCCACHE immediately resolves the problem system-wide.  As we have not yet identified the problematic query, we’ve put a temporary solution in place that frees the procedure cache on an hourly basis via a SQL Agent job.  This is not ideal, but it is getting us through the day without a major problem.  We are actively working on identifying the problematic query and hope to disable the SQL Agent job soon. Earlier this week, we had a major slowdown for one of the processes of this application.  I was unable to find any database performance issues, but I continued to investigate it.  One of things that I typically do when investigating database performance issues is run the “Missing Indexes DMV Report” (that’s what I call it at least).  When analyzing the output of that report, I immediately dismiss anything under 1 million “Impact” as I want to target the “low-hanging fruit” initially.  When I ran the report earlier this week, I was shocked to find a suggested index with an impact of over 3 billion! Do I win a prize for the highest impact?  Has anyone seen a value higher than mine?  My exact value was 3154284120.67765. The performance issue from earlier this week ended up being an application problem, but it also brought to light a much needed index.  I had previously seen this index come up in that report but always with a much lower impact.  I had never considered it as the index’s selectivity is very low.  It’s a composite index with three columns.  The first column is not selective, the first two columns are not selective, and the three columns together are not selective.  In fact, no matter how I order it, the index will not be selective at all.  I briefly discussed this with Kimberly Tripp, and she said that this was okay for covering indexes.  Selectivity is irrelevant for a covering index.  She indicated that she’s even created indexes with gender as the first column in the index.  I’ve got lots to learn still!

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• Multiple Object Instantiation

  - by Ricky Baby

  I am trying to get my head around object oriented programming as it pertains to web development (more specifically PHP). I understand inheritance and abstraction etc, and know all the "buzz-words" like encapsulation and single purpose and why I should be doing all this. But my knowledge is falling short with actually creating objects that relate to the data I have in my database, creating a single object that a representative of a single entity makes sense, but what are the best practises when creating 100, 1,000 or 10,000 objects of the same type. for instance, when trying to display a list of the items, ideally I would like to be consistent with the objects I use, but where exactly should I run the query/get the data to populate the object(s) as running 10,000 queries seems wasteful. As an example, say I have a database of cats, and I want a list of all black cats, do I need to set up a FactoryObject which grabs the data needed for each cat from my database, then passes that data into each individual CatObject and returns the results in a array/object - or should I pass each CatObject it's identifier and let it populate itself in a separate query.

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• Coherence 3.7.1 Released

  - by JuergenKress

  Oracle Coherence 3.7.1 introduces REST API, exalogic infiniband integration, improved data access performance due to more efficient in-memory and disk-based storage, and query explain plan support and much more, download now! View the webcast: Unbeatable Performance for your Cloud Application Foundation. To download Coherence 3.7.1 please visit OTN. Coherence Screencasts: Coherence 3.7.1 – Extend Only Keys Coherence 3.7.1 – REST Support Coherence 3.7.1 – POF Object Identities and References Coherence 3.7.1 – POF Annotation Support Coherence 3.7.1 – Query Explain Plan For more information please visit the Oracle Coherence Knowledge Base For regular Coherence information become a member in the WebLogic Partner Community please first login at http://partner.oracle.com and then visit: http://www.oracle.com/partners/goto/wls-emea Blog Twitter LinkedIn Mix Forum Wiki Technorati Tags: Coherence,Coherence 3.7.1,Oracle,WebLogic,J2EE caching,OPN,Jürgen Kress

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• Should all foreign table references use foreign key constraints

  - by TecBrat

  Closely related to: Foreign key restrictions -> yes or no? I asked a question on SO and it led me to ask this here. If I'm faced with a choice of having a circular reference or just not enforcing the restraint, which is the better choice? In my particular case I have customers and addresses. I want an address to have a reference to a customer and I want each customer to have a default billing address id and a default shipping address id. I might query for all addresses that have a certain customer ID or I might query for the address with the ID that matches the default shipping or billing address ids. I'm not sure yet how the constraints (or lack of) will effect the system as my application and it's data age.

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• HSSFS Part 3: SQL Saturday is Awesome! And DEFAULT_DOMAIN(), and how I found it

  - by Most Valuable Yak (Rob Volk)

  Just a quick post I should've done yesterday but I was recovering from SQL Saturday #48 in Columbia, SC, where I went to some really excellent sessions by some very smart experts.  If you have not yet attended a SQL Saturday, or its been more than 1 month since you last did, SIGN UP NOW! While searching the OBJECT_DEFINITION() of SQL Server system procedures I stumbled across the DEFAULT_DOMAIN() function in xp_grantlogin and xp_revokelogin.  I couldn't find any information on it in Books Online, and it's a very simple, self-explanatory function, but it could be useful if you work in a multi-domain environment.  It's also the kind of neat thing you can find by using this query: SELECT OBJECT_SCHEMA_NAME([object_id]) object_schema, name FROM sys.all_objects WHERE OBJECT_DEFINITION([object_id]) LIKE '%()%'  ORDER BY 1,2 I'll post some elaborations and enhancements to this query in a later post, but it will get you started exploring the functional SQL Server sea. UPDATE: I goofed earlier and said SQL Saturday #46 was in Columbia. It's actually SQL Saturday #48, and SQL Saturday #46 was in Raleigh, NC.

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• Don't Miss - Oracle ADF Virtual Developer Day 2013

  - by Shay Shmeltzer

  With budget cuts all over the world less and less developers get to travel to conferences. So how do you keep up with the latest technical aspects of your development environment? Oracle to the rescue with our Virtual Developer Day.  We are happy to announce the 2013 Oracle ADF Virtual Developer Days Online sessions that include a live Q&A with product managers that will cover everything you need to know about Oracle ADF - all from the comfort of your office chair. With sessions that cover best practices, tuning, mobile, Eclipse support and even some getting started information there is something in this day for every level of experience with Oracle ADF - you are sure to learn some new things too! Sessions are delivered by Oracle product managers with a special track delivered by expert customers covering some advanced topics. Check out the schedule and register for the event in your time zone.

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• Oracle University Nouveaux cours (Week 10)

  - by swalker

  Parmi les nouveautés d’Oracle Université de ce mois-ci, vous trouverez : Database RAC & Grid Infrastructure for Oracle Solaris System Administration (1 day) Oracle Database 11g: Performance Tuning (Training On Demand) Development Tools Oracle Database: Program with PL/SQL (Training On Demand) MySQL MySQL for Database Administrators (Training On Demand) Fusion Middleware Oracle SOA Suite 11g : Concepts de base (3 days) Oracle WebCenter Portal 11g: Build Portals With Spaces (3 days) Oracle WebCenter Content 11g: Site Studio Essentials (5 days) Oracle BPM 11g Modeling (3 days) Business Intelligence & Datawarehousing Oracle BI 11g : Mise à niveau et nouvelles fonctionnalités (2 days) Oracle BI Applications 7.9.6: Implementation for Oracle EBS (4 days) Oracle BI Applications 7.9.6: Implementation for Siebel CRM (4 days) Oracle BI 11g R1: Build Repositories (Training on Demand) Fusion Applications Fusion Applications: Extend Applications with ADF (5 days) E-Business Suite R12.x Extend Oracle Applications: Building OA Framework Applications (Training On Demand) PeopleSoft PeopleSoft Integration Tools Rel 8.50 (Training On Demand) Contacter l’équipe locale d’Oracle University pour toute information et dates de cours.

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• SCCM 2007 Collections per OU

  - by VirtualizeIT

  Recently I wanted to create our SCCM collections setup as our Active Directory structure. I finally figured out how to create collections per OU of the domain. I decided to create a simple tutorial that may help other IT professionals the steps to complete this task.   1. Open the ConfigMgr and navigation to the collections. To navigate to the collections go to Site Database>Computer Management>Collections. 2. In the ‘Collections’ right-click and select New Collections. Then it will pop up a Wizards so you can enter the name of the collection and any notes that you may want to add that is associated with the collection.                       3. Next, select the database icon. In the ‘Name’ textbox enter the name of the query. I named mine ‘Query’ just for simplicity sake. After you enter the name select ‘Edit Query Statement…’ 4. Select the ‘Criteria’ tab 5. Select the icon that looks like a sun. 6. At this point you should see a dialog box like this…                     7. Next, click the ‘select’ button. 8. Under the ‘Attribute class’ scroll through until you see ’System Resource’ and for the ‘Attribute"’ scroll through you see ‘System OU Name’. It should look something like this…                 9. After that select OK. 10. In the ‘Value’ textbox enter the string that is associated with the OU in your domain. NOTE: If you don’t know your string name for your OU you can simply go to “Active Directory Users and Computers” and right-click on the OU and select properties. In the ‘object’ tab you should see the string under the ‘Canonical name of object”. That is the string that you put in the ‘Value’ text box. 11. After you enter the OU string name press OK>OK>OK>NEXT>NEXT>FINISH.   That’s it!   I hope this tutorial has help you understand how to create a collection through your OU structure.

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• ApiChange Corporate Edition

  - by Alois Kraus

  In my inital announcement I could only cover a small subset what ApiChange can do for you. Lets look at how ApiChange can help you to fix bugs due to wrong usage of an Api within a fraction of time than it would take normally. It happens that software is tested and some bugs show up. One bug could be …. : We get way too man log messages during our test run. Now you have the task to find the most frequent messages and eliminate the Log calls from the source code. But what about the myriads other log calls? How can we check that the distribution of log calls is nearly equal across all developers? And if not how can we contact the developer to check his code? ApiChange can help you too connect these loose ends. It combines several information silos into one cohesive view. The picture below shows how it is able to fill the gaps. The public version does currently “only” parse the binaries and pdbs to give you for a –whousesmethod query the following colums: If it happens that you have Rational ClearCase (a source control system) in your development shop and an Active Directory in place then ApiChange will try to determine from the source file which was determined from the pdb the last check in user which should be present in your Active Directory. From there it is only a small hop to an LDAP query to your AD domain or the GC (Global Catalog) to get from the user name his Full name Email Phone number Department …. ApiChange will append this additional data all of your query results which contain source files if you add the –fileinfo option. As I said this is currently not enabled by default since the AD domain needs to be configured which are currently only some hard coded values in the SiteConstants.cs source file of ApiChange.Api.dll. Once you got this data you can generate metrics based on source file, developer, assembly, … and add additional data by drag and drop directly into the pivot tables inside Excel. This allows you to e.g. to generate a report which lists the source files with most log calls in descending order along with the developer name and email in the pivot table. Armed with this knowledge you can take meaningful measures e.g. to ask the developer if the huge number of log calls in this source file can be optimized. I am aware that this is a very specific scenario but it is a huge time saver when you are able to fill the missing gaps of information. ApiChange does this in an extensible way. namespace ApiChange.ExternalData {     public interface IFileInformationProvider     {         UserInfo GetInformationFromFile(string fileName);     } } It defines an interface where you can implement your custom information provider to close the gap between source control system and the real person I have to send an email to ask if his code needs a closer inspection.

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• BizTalk 2009 - Service Instances: Last 100

  - by StuartBrierley

  Having previously talked about the lack of the traditional HAT in BizTalk 2009, the question then becomes how do you replicate some of the functionality that was previsouly relied on? I have already covered the Last 100 Messages Received, the Last 100 Messages Sent, and the Last 50 Suspended Messages queries so what about service instances? The BizTalk 2009 Group Hub allows you to search for suspended service instances and also running service instances, but not the two together. In BizTalk 2004 we had a query in HAT to return the last 100 service instances.  Lets create a direct replacement in the BizTalk 2009 Hatless environment. Basically we are creating a query to search for the last one hundred tracked service instances:

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• How to join two collections with LINQ

  - by JustinGreenwood

  Here is a simple and complete example of how to perform joins on two collections with LINQ. I wrote it for a friend to show him, in one simple file, the power of LINQ queries and anonymous objects. In the file below, there are two simple data classes defined: Person and Item. In the beginning of the main method, two collections are created. Note that the Item's OwnerId field reference the PersonId of a Person object. The effect of the LINQ query below is equivalent to a SQL statement looking like this: select Person.PersonName as OwnerName, Item.ItemName as OwnedItem from Person inner join Item on Item.OwnerId = Person.PersonId order by Item.ItemName desc; using System; using System.Collections.Generic; using System.Linq; namespace LinqJoinAnonymousObjects { class Program { class Person { public int PersonId { get; set; } public string PersonName { get; set; } } class Item { public string ItemName { get; set; } public int OwnerId { get; set; } } static void Main(string[] args) { // Create two collections: one of people, and another with their possessions. var people = new List<Person> { new Person { PersonId=1, PersonName="Justin" }, new Person { PersonId=2, PersonName="Arthur" }, new Person { PersonId=3, PersonName="Bob" } }; var items = new List<Item> { new Item { OwnerId=1, ItemName="Armor" }, new Item { OwnerId=1, ItemName="Book" }, new Item { OwnerId=2, ItemName="Chain Mail" }, new Item { OwnerId=2, ItemName="Excalibur" }, new Item { OwnerId=3, ItemName="Bubbles" }, new Item { OwnerId=3, ItemName="Gold" } }; // Create a new, anonymous composite result for person id=2. var compositeResult = from p in people join i in items on p.PersonId equals i.OwnerId where p.PersonId == 2 orderby i.ItemName descending select new { OwnerName = p.PersonName, OwnedItem = i.ItemName }; // The query doesn't evaluate until you iterate through the query or convert it to a list Console.WriteLine("[" + compositeResult.GetType().Name + "]"); // Convert to a list and loop through it. var compositeList = compositeResult.ToList(); Console.WriteLine("[" + compositeList.GetType().Name + "]"); foreach (var o in compositeList) { Console.WriteLine("\t[" + o.GetType().Name + "] " + o.OwnerName + " - " + o.OwnedItem); } Console.ReadKey(); } } } The output of the program is below: [WhereSelectEnumerableIterator`2] [List`1] [<>f__AnonymousType1`2] Arthur - Excalibur [<>f__AnonymousType1`2] Arthur - Chain Mail

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• BigQuery - Best Practices for Running Queries on Massive Datasets

  BigQuery - Best Practices for Running Queries on Massive Datasets Join Michael Manoochehri and Ryan Boyd from the big data Developer Relations team on Friday, September 21th, at 10am PDT, as they discuss best practices for answering questions about massive datasets with Google BigQuery. They'll explore interesting Big Data use cases with some of our public datasets, using BigQuery's SQL-like language to return query results in seconds. They will also cover some of BigQuery's unique query functions as well. For a general overview of BigQuery, watch our overview video: youtu.be Please use the moderator below (goo.gl to ask your questions, which will be answered live! More info here: developers.google.com From: GoogleDevelopers Views: 0 0 ratings Time: 00:00 More in Science & Technology

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• Agile Entity Framework 4 Repository: Part 6: Mocks & Unit Tests

  I did finish this series, honest I did. But not in the blog. Ive shown this in a number of conferences and even in my book, but I never came back and wrote it all down. In fact, I had the whole solutino written before I began the series, but it has gone through a lot of changes. Where did I leave off? Agile Entity Framework 4 Repository: Part 1- Model and POCO Classes Agile Entity Framework 4 Repository: Part 2- The Repository Agile EF4 Repository: Part 3 -Fine Tuning the Repository Agile...Did you know that DotNetSlackers also publishes .net articles written by top known .net Authors? We already have over 80 articles in several categories including Silverlight. Take a look: here.

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• I need recommendations on free, open source, PHP-based business intelligence widget frameworks [on hold]

  - by Volomike

  I'm a PHP developer on Linux, and my manager wants a business intelligence dashboard. He wants to see in real-time our profit/loss stuff in fancy charts, based on our software sales. I could code it all from scratch and use Google Charts API or some other charts API to help me. However, I wanted to know if there was a free, open source, PHP-based business intelligence package out there, or some sort of widget framework that I could start with. That way, I can build the BI widgets inside that framework and not have to do everything from scratch. I apologize ahead of time if this is the wrong stackexchange where to place this query. I don't know where to place this query, and do want to follow the rules.

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• Windows in StreamInsight: Hopping vs. Snapshot

  - by Roman Schindlauer

  Three weeks ago, we explained the basic concept of windows in StreamInsight: defining sets of events that serve as arguments for set-based operations, like aggregations. Today, we want to discuss the so-called Hopping Windows and compare them with Snapshot Windows. We will compare these two, because they can serve similar purposes with different behaviors; we will discuss the remaining window type, Count Windows, another time. Hopping (and its syntactic-sugar-sister Tumbling) windows are probably the most straightforward windowing concept in StreamInsight. A hopping window is defined by its length, and the offset from one window to the next. They are aligned with some absolute point on the timeline (which can also be given as a parameter to the window) and create sets of events. The diagram below shows an example of a hopping window with length of 1h and hop size (the offset) of 15 minutes, hence creating overlapping windows:   Two aspects in this diagram are important: Since this window is overlapping, an event can fall into more than one windows. If an (interval) event spans a window boundary, its lifetime will be clipped to the window, before it is passed to the set-based operation. That’s the default and currently only available window input policy. (This should only concern you if you are using a time-sensitive user-defined aggregate or operator.) The set-based operation will be applied to each of these sets, yielding a result. This result is: A single scalar value in case of built-in or user-defined aggregates. A subset of the input payloads, in case of the TopK operator. Arbitrary events, when using a user-defined operator. The timestamps of the result are almost always the ones of the windows. Only the user-defined  operator can create new events with timestamps. (However, even these event lifetimes are subject to the window’s output policy, which is currently always to clip to the window end.) Let’s assume we were calculating the sum over some payload field: var result = from window in source.HoppingWindow( TimeSpan.FromHours(1), TimeSpan.FromMinutes(15), HoppingWindowOutputPolicy.ClipToWindowEnd) select new { avg = window.Avg(e => e.Value) }; Now each window is reflected by one result event:   As you can see, the window definition defines the output frequency. No matter how many or few events we got from the input, this hopping window will produce one result every 15 minutes – except for those windows that do not contain any events at all, because StreamInsight window operations are empty-preserving (more about that another time). The “forced” output for every window can become a performance issue if you have a real-time query with many events in a wide group & apply – let me explain: imagine you have a lot of events that you group by and then aggregate within each group – classical streaming pattern. The hopping window produces a result in each group at exactly the same point in time for all groups, since the window boundaries are aligned with the timeline, not with the event timestamps. This means that the query output will become very bursty, delivering the results of all the groups at the same point in time. This becomes especially obvious if the events are long-lasting, spanning multiple windows each, so that the produced result events do not change their value very often. In such a case, a snapshot window can remedy. Snapshot windows are more difficult to explain than hopping windows: they represent those periods in time, when no event changes occur. In other words, if you mark all event start and and times on your timeline, then you are looking at all snapshot window boundaries:   If your events are never overlapping, the snapshot window will not make much sense. It is commonly used together with timestamp modification, which make it a very powerful tool. Or as Allan Mitchell expressed in in a recent tweet: “I used to look at SnapshotWindow() with disdain. Now she is my mistress, the one I turn to in times of trouble and need”. Let’s look at a simple example: I want to compute the average of some value in my events over the last minute. I don’t want this output be produced at fixed intervals, but at soon as it changes (that’s the true event-driven spirit!). The snapshot window will include all currently active event at each point in time, hence we need to extend our original events’ lifetimes into the future: Applying the Snapshot window on these events, it will appear to be “looking back into the past”: If you look at the result produced in this diagram, you can easily prove that, at each point in time, the current event value represents the average of all original input event within the last minute. Here is the LINQ representation of that query, applying the lifetime extension before the snapshot window: var result = from window in source .AlterEventDuration(e => TimeSpan.FromMinutes(1)) .SnapshotWindow(SnapshotWindowOutputPolicy.Clip) select new { avg = window.Avg(e => e.Value) }; With more complex modifications of the event lifetimes you can achieve many more query patterns. For instance “running totals” by keeping the event start times, but snapping their end times to some fixed time, like the end of the day. Each snapshot then “sees” all events that have happened in the respective time period so far. Regards, The StreamInsight Team

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• I want a trivial example of where MongoDB can scale but a relational database will have trouble

  - by Ryan Weir

  I'm just learning to use MongoDB, and when discussing with other programmers would like a quick example of why NoSQL can be a good choice compared to a traditional RDBMS - however the scenarios I come up with and can find online seem pretty contrived. E.g. a blog with lots of traffic could be represented relationally, but will require some performance tuning and joins across tables (assuming full denormalization is being used). Whereas MongoDB would allow direct retrieval from one collection to the same effect. But the response I'm getting from other programmers is "why not just keep it relational and then add some trivial caching later?" Does anybody have a less contrived example where MongoDB will really shine and a relational db will fall over much quicker? The smaller the project/system the better, because it leaves less room for disagreement. Something along the lines of the complexity of the blog example would be really useful. Thanks.

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• Is it time to drop Courier from your monospace font stacks?

  - by Jeff

  I've been fine-tuning my font stacks lately and was wondering if it's safe to drop Courier from my monospace font stack yet? Would you feel comfortable dropping it? Of course, monospace is my final fallback. Note 1: OS Testbed: WinXP, WinVista, Win7, iPhone, iPad Based on my research, these browsers now substitute Courier New for Courier by default: IE9+ Chrome 2+ Firefox 10+ Safari 3.1+ iDevices Note 2: The default "font-family: monospace;" renders as Courier New in every browser I've tested, from IE6 through the latest iPhone/iPad devices. EDIT: One exception is Opera 12, which renders Consolas on Win. Opera 10 renders Courier New. Note 3: I've noticed that Courier refuses to render with any font smoothing (anti-aliasing) in any browser I've tested, regardless of system and/or browser display settings. Probably because it's an old bitmap font. This could be because of my system setup, however.

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• Oracle SOA Suite 11g Administrator's Handbook

  - by Antony Reynolds

  SOA Administration Book I have just received a copy of the “Oracle SOA Suite 11g Administrator's Handbook” so as soon as I have read it I will let you know what I think.  In the meantime the first thing that struck me was the author credentials, although I have never met either of them as I remember, I have read Admeds blog postings and they are a great community resource, so immediately I am well disposed towards the book.  Similarly Arun is an employee of my friend and co-author Matt Wright, and I have heard good things about him from Rubicon Red people. A first glance at the table of contents looks encouraging, I particularly like their approach to performance tuning where they give a clear concise explanation of the knobs they are using. More when I have read more.

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• Slow gvfs Samba Performance

  - by Wolfgang

  if I use/acces a Samba Share using Nautilus or manually using "gvfs-mount smb://SERVER-IP/Share" I get a poor Performance, only about 7 mb/s on my 100 Mbit Network. If I access the same Share on Windows I get Fullspeed 100 Mbit (About 11 mb/s), also if I mount using sudo mount -t cifs //SERVER-IP/Share /mountpount which uses cifs instead of gvfs I get fullspeed too, so can anyone tell me if there is a Performance Problem/Bug in gvfs or how gvfs is using SMB Shares differerently ? I tested read Perfomance (From my Network Samba Share) with multiples files and always, the cifs-Version is fullspeed and the GVFS-Version has some mb/s less. After some research I found some tips to optimize the Samba Settings of my Ubuntu Installation and some network tuning tips, but as the CIFS mounted share gets the full Network Speed I don't believe its that kind of problem.

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• MERGE gives better OUTPUT options

  - by Rob Farley

  MERGE is very cool. There are a ton of useful things about it – mostly around the fact that you can implement a ton of change against a table all at once. This is great for data warehousing, handling changes made to relational databases by applications, all kinds of things. One of the more subtle things about MERGE is the power of the OUTPUT clause. Useful for logging.   If you’re not familiar with the OUTPUT clause, you really should be – it basically makes your DML (INSERT/DELETE/UPDATE/MERGE) statement return data back to you. This is a great way of returning identity values from INSERT commands (so much better than SCOPE_IDENTITY() or the older (and worse) @@IDENTITY, because you can get lots of rows back). You can even use it to grab default values that are set using non-deterministic functions like NEWID() – things you couldn’t normally get back without running another query (or with a trigger, I guess, but that’s not pretty). That inserted table I referenced – that’s part of the ‘behind-the-scenes’ work that goes on with all DML changes. When you insert data, this internal table called inserted gets populated with rows, and then used to inflict the appropriate inserts on the various structures that store data (HoBTs – the Heaps or B-Trees used to store data as tables and indexes). When deleting, the deleted table gets populated. Updates get a matching row in both tables (although this doesn’t mean that an update is a delete followed by an inserted, it’s just the way it’s handled with these tables). These tables can be referenced by the OUTPUT clause, which can show you the before and after for any DML statement. Useful stuff. MERGE is slightly different though. With MERGE, you get a mix of entries. Your MERGE statement might be doing some INSERTs, some UPDATEs and some DELETEs. One of the most common examples of MERGE is to perform an UPSERT command, where data is updated if it already exists, or inserted if it’s new. And in a single operation too. Here, you can see the usefulness of the deleted and inserted tables, which clearly reflect the type of operation (but then again, MERGE lets you use an extra column called $action to show this). (Don’t worry about the fact that I turned on IDENTITY_INSERT, that’s just so that I could insert the values) One of the things I love about MERGE is that it feels almost cursor-like – the UPDATE bit feels like “WHERE CURRENT OF …”, and the INSERT bit feels like a single-row insert. And it is – but into the inserted and deleted tables. The operations to maintain the HoBTs are still done using the whole set of changes, which is very cool. And $action – very convenient. But as cool as $action is, that’s not the point of my post. If it were, I hope you’d all be disappointed, as you can’t really go near the MERGE statement without learning about it. The subtle thing that I love about MERGE with OUTPUT is that you can hook into more than just inserted and deleted. Did you notice in my earlier query that my source table had a ‘src’ field, that wasn’t used in the insert? Normally, this would be somewhat pointless to include in my source query. But with MERGE, I can put that in the OUTPUT clause. This is useful stuff, particularly when you’re needing to audit the changes. Suppose your query involved consolidating data from a number of sources, but you didn’t need to insert that into the actual table, just into a table for audit. This is now very doable, either using the INTO clause of OUTPUT, or surrounding the whole MERGE statement in brackets (parentheses if you’re American) and using a regular INSERT statement. This is also doable if you’re using MERGE to just do INSERTs. In case you hadn’t realised, you can use MERGE in place of an INSERT statement. It’s just like the UPSERT-style statement we’ve just seen, except that we want nothing to match. That’s easy to do, we just use ON 1=2. This is obviously more convoluted than a straight INSERT. And it’s slightly more effort for the database engine too. But, if you want the extra audit capabilities, the ability to hook into the other source columns is definitely useful. Oh, and before people ask if you can also hook into the target table’s columns... Yes, of course. That’s what deleted and inserted give you.

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• 5 Things SQL Server should get rid of

  - by Jonathan Kehayias

  Paul Randal ( blog | twitter ) started a new meme last night with his blog post " What 5 things should SQL Server get rid of? " A few bloggers have posted their top 5 lists, so here is mine. Creating Foreign Keys without mentioning Indexes This is probably a performance tuning consultants favorite.  I know that Greg Low has blogged about this in the past (see Indexing Foreign Keys - should SQL Server do that automatically? ) and back then, and now I still do think this should be an...(read more)

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• Remote connection problem.

  - by Woody

  Hello I have ubuntu 10.04 installed with mysql on it and I have a problem with remote connection. When I connect through putty it works but sometimes it looks like it hangs for example when I execute the command ln --help. Also with MySQL connection When I execute a simple query like show processlist; it works, but for example select * from table not always, if the table doesn't have many rows it works but if it has let's say more than 20 the query looks like it keeps working and never ends. It's connected but I can't do many things remotely. Added: I connect using putty from other windows pc, server is not overloaded. when i work at the same time directly on ubuntu i can do everything. Remotely not.

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• Querying Literals in Entity SQL

  Entity SQL might surprise you if you are building query expressions with some non-string types. Ive blogged about this before with the DateTime literal after trying to use a string to represent the date in my query as Im used to with TSQL. Here is a snip from that post: SELECT VALUE BAModel.Contact(c.ContactID,c.FirstName,c.LastName,c.Title,c.AddDate,c.ModifiedDate) FROM dbo.Contact as c WHERE c.AddDate>="1/1/2007" I was trying to emulate T-SQL here but I need...Did you know that DotNetSlackers also publishes .net articles written by top known .net Authors? We already have over 80 articles in several categories including Silverlight. Take a look: here.

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• WebCenter Customer Spotlight: Guizhou Power Grid Company

  - by me

  Author: Peter Reiser - Social Business Evangelist, Oracle WebCenter  Solution SummaryGuizhou Power Grid Company is responsible for power grid planning, construction, management, and power distribution in Guizhou Province, serving 39 million people. Giuzhou has 49,823 employees and an annual revenue of over $5 Billion. The business objectives were to consolidate information contained in disparate systems into a single knowledge repository and provide a safe and efficient way for staff and managers to access, query, share, manage, and store business information. Guizhou Power Grid Company saved more than US$693,000 in storage costs, reduced  average search times from 180 seconds to 5 seconds and solved 80% to 90% of technology and maintenance issues by searching the Oracle WebCenter Content management system. Company OverviewA wholly owned subsidiary of China Southern Power Grid Company Limited, Guizhou Power Grid Company is responsible for power grid planning, construction, management, and power distribution in Guizhou Province, serving 39 million people. Giuzhou has 49,823 employees and an annual revenue of over $5 Billion. Business ChallengesThe business objectives were to consolidate information contained in disparate systems, such as the customer relationship management and power grid management systems, into a single knowledge repository and provide a safe and efficient way for staff and managers to access, query, share, manage, and store business information. Solution DeployedGuizhou Power Grid Company  implemented Oracle WebCenter Content to build a content management system that enabled the secure, integrated management and storage of information, such as documents, records, images, Web content, and digital assets. The content management solution was integrated with the power grid, customer service, maintenance, and other business systems, as well as the corporate Web site. Business Results Saved more than US$693,000 in storage costs and shortened the material distribution time by integrating the knowledge management solution with the power grid, customer service, maintenance, and other business systems, as well as the corporate Web site Enabled staff to search 31,650 documents using catalogs, multidimensional attributes, and knowledge maps, reducing average search times from 180 seconds to 5 seconds and saving approximately 1,539 hours in annual search time Gained comprehensive document management, format transformation, security, and auditing capabilities Enabled users to upload new documents and supervisors to check the accuracy of these documents online, resulting in improved information quality control Solved 80% to 90% of technology and maintenance issues by searching the Oracle content management system for information, ensuring IT staff can respond quickly to users’ technical problems Improved security by using role-based access controls to restrict access to confidential documents and information Supported the efficient classification of corporate knowledge by using Oracle’s metadata functions to collect, tag, and archive documents, images, Web content, and digital assets “We chose Oracle WebCenter Content, as it is an outstanding integrated content management platform. It has allowed us to establish a system to access, query, share, manage, and store our corporate assets. This has laid a solid foundation for Guizhou Power Grid Company to improve management practices.” Luo Sixi, Senior Information Consultant, Guizhou Power Grid Company Additional Information Guizhou Power Grid Company Customer Snapshot Oracle WebCenter Content

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• how does server communication work in a flash game with a php backend

  - by Tim Rogers

  I am trying to create a browser game using actionscript/flash. Currently, I'm trying to understand how I would go about creating a back-end which interfaced with my MySQL database. As far as I understand, If I create a php file on a webserver called test.php and then navigate to a webpage hosted on the server eg. www.example.com/test, the php script will run and display the result in my browser. This would use http. Is this how communication between client and server usually works in a flash game? for example, if the game needed to query the db. Would actionscript have to essentially invoke the url of the php script that would execute the query? it could then parse the data and use it. If this is the case, then is JSON considered a good way to transfer data over http?

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