Sub query pass through

Posted by SQL and the like on SQL Blogcasts See other posts from SQL Blogcasts or by SQL and the like
Published on Fri, 22 Mar 2013 09:10:14 GMT Indexed on 2013/06/24 16:30 UTC
Read the original article Hit count: 317

Filed under:

tsql

|

SQLServer

|

Query Plan

|

optimizer

Occasionally in forums and on client sites I see conditional subqueries in statements. This is where the developer has decided that it is only necessary to process some data under a certain condition. By way of example, something like this : Create Procedure GetOrder @SalesOrderId integer, @CountDetails tinyint as Select SOH.salesorderid , case when @CountDetails = 1 then (Select count(*) from Sales.SalesOrderDetail SOD where SOH.SalesOrderID = SOD.SalesOrderID) end from sales.SalesOrderHeader...(read more)

© SQL Blogcasts or respective owner

Related posts about tsql

TSQL Challenge 30 - A Matrix Transposition challenge in TSQL

as seen on SQL Server Central - Search for 'SQL Server Central'
This is a matrix transposition challenge. Your job is to change the position of the numbres in a 5x5 matrix. SQL Server monitoring made easy "Keeping an eye on our many SQL Server instances is much easier with SQL Response." Mike Lile.Download a free trial of SQL Response… >>> More
Will TSQL become useless because of new ORMs? [closed]

as seen on Programmers - Search for 'Programmers'
By introducing LINQ to SQL, I found myself and my .NET developer colleagues gradually moving from TSQL to C# to create queries on the database. Entity Framework made that shift almost permanent. Now it's nearly 2 years that I use LINQ to SQL and LINQ to Entities and haven't used TSQL that much. Yesterday… >>> More
Issue Creating SQL Login for AppPoolIdentity on Windows Server 2008

as seen on Johnny Coder - Search for 'Johnny Coder'
IIS7 introduced the option to run your application pool as AppPoolIdentity. With the release of IIS7.5, AppPoolIdentity was promoted to the default option. You see this change if you’re running Windows 7 or Windows Server 2008 R2. On my Windows 7 machine, I’m able to define my Application… >>> More
The best, in the West

as seen on Simple Talk - Search for 'Simple Talk'
As many of you know, I run the SQL South West user group and we are currently in full flow preparing to stage the UK’s second SQL Saturday. The SQL Saturday spotlight is going to fall on Exeter in March 2013. We have full-day session on Friday 8th with some truly amazing speakers giving their… >>> More
Something for the weekend - Whats the most complex query?

as seen on SQL Blogcasts - Search for 'SQL Blogcasts'
Whenever I teach about SQL Server performance tuning I try can get across the message that there is no such thing as a table. Does that sound odd, well it isn't, trust me. Rather than tables you need to consider structures. You have 1. Heaps 2. Indexes (b-trees) Some people split indexes… >>> More

Related posts about SQLServer

High Sqlservr.exe Memory Usage

as seen on Server Fault - Search for 'Server Fault'
I have a problem with sqlservr.exe (version 2008). It use a more memory. I checked on windows taskbar manager, sqlservr.exe usage ( Mem usage - 8GB Ram). I dont know how can I fix it.Got the following metrics of the server using Perfmon: SQLServer:Buffer Manager Buffer cache hit ratio 13 SQLServer:Buffer… >>> More
SQL server 2008 R2 installation error

as seen on Super User - Search for 'Super User'
I have a windows 7,32 bit laptop. I am the administrator with all permissions. when I click on the SQL server 2008R2 set up file,it says : "SQL server set up has encountered the following error:Failed to retreive data for this request" click on OK. I have uninstalled all the components of SQL from… >>> More
SQL Monitor’s data repository: Alerts

as seen on Simple Talk - Search for 'Simple Talk'
In my previous post, I introduced the SQL Monitor data repository, and described how the monitored objects are stored in a hierarchy in the data schema, in a series of tables with a _Keys suffix. In this post I had planned to describe how the actual data for the monitored objects is stored in corresponding… >>> More
CreationName for SSIS 2008 and adding components programmatically

as seen on SQLIS - Search for 'SQLIS'
If you are building SSIS 2008 packages programmatically and adding data flow components, you will probably need to know the creation name of the component to add. I can never find a handy reference when I need one, hence this rather mundane post. See also CreationName for SSS 2005. We start with… >>> More
SQL SERVER – Introduction to Extended Events – Finding Long Running Queries

as seen on SQL Authority - Search for 'SQL Authority'
The job of an SQL Consultant is very interesting as always. The month before, I was busy doing query optimization and performance tuning projects for our clients, and this month, I am busy delivering my performance in Microsoft SQL Server 2005/2008 Query Optimization and & Performance Tuning Course… >>> More