SQL Performance Archives - Page 92 of 101 - SQL Authority with Pinal Dave

SQL SERVER – Explanation and Understanding NOT NULL Constraint

October 15, 2007

SQL, SQL Performance, SQL Server, SQL Tips and Tricks

SQL Constraint and Keys, SQL Joins, SQL NULL, SQL Scripts

NOT NULL is integrity CONSTRAINT. It does not allow creating of the row where column contains NULL value. Most discussed question about NULL is what is NULL? I will not go in depth analysis it. Simply put NULL is unknown or missing data. When NULL is present in database columns,…

SQL SERVER – Three Rules to Use UNION

October 14, 2007

Pinal Dave

SQL, SQL Performance, SQL Server, SQL Tips and Tricks

SQL Joins, SQL Scripts, SQL Union clause

I have previously written two articles on UNION and they are quite popular. I was reading SQL book Sams Teach Yourself Microsoft SQL Server T-SQL in 10 Minutes By Ben Forta and I came across three rules of UNION and I felt like mentioning them here. UNION RULES A UNION…

SQL SERVER – 2005 – Explanation of TRY…CATCH and ERROR Handling With RAISEERROR Function

October 3, 2007

Pinal Dave

SQL, SQL Performance, SQL Server, SQL Tips and Tricks

SQL Error Messages, SQL Scripts

One of the developer at my company thought that we can not use RAISEERROR function in new feature of SQL Server 2005 TRY…CATCH. When asked for explanation he suggested SQL SERVER – 2005 Explanation of TRY…CATCH and ERROR Handling article as excuse suggesting that I did not give example of…

SQL SERVER – 2005 – OUTPUT Clause Example and Explanation with INSERT, UPDATE, DELETE

October 1, 2007

Pinal Dave

SQL, SQL Performance, SQL Server, SQL Tips and Tricks

SQL Scripts

SQL Server 2005 has new OUTPUT clause, which is quite useful. OUTPUT clause has accesses to inserted and deleted tables (virtual tables) just like triggers. OUTPUT clause can be used to return values to client clause. OUTPUT clause can be used with INSERT, UPDATE, or DELETE to identify the actual…

SQL SERVER – Order of Result Set of SELECT Statement on Clustered Indexed Table When ORDER BY is Not Used

September 24, 2007

Pinal Dave

SQL Performance

SQL Index, SQL Order By, SQL Server

“What will be the order of the result set of a SELECT statement on clustered indexed table when the ORDER BY clause is not used?”

SQL SERVER – Actual Execution Plan vs. Estimated Execution Plan

August 28, 2007

Pinal Dave

SQL, SQL Performance, SQL Server, SQL Tips and Tricks

DBA, Execution Plan, SQL Scripts

I was recently invited to participate in big discussion on one of the online forum, the topic was Actual Execution Plan vs. Estimated Execution Plan. I refused to participate in that particular discussion as I have very simple but strong opinion about this topic. I always use Actual Execution Plan…

SQL SERVER – 2005 – Explanation and Script for Online Index Operations – Create, Rebuild, Drop

August 17, 2007

Pinal Dave

SQL, SQL Performance, SQL Server, SQL Tips and Tricks

SQL Index, SQL Scripts, SQL Server DBCC

SQL Server 2005 Enterprise Edition supports online index operations. Index operations are creating, rebuilding and dropping indexes. The question which I receive quite often – what is online operation? Is online operation is related to web, internet or local network? Online operation means when online operations are happening the database…