2012-11-30
2,392 reads
Referential Integrity
Using SET NULL and SET DEFAULT with Foreign Key Constraints
Cascading Updates and Deletes, introduced with SQL Server 2000, were such an important, crucial feature that it is hard to imagine providing referential integrity without them. One of the new features in SQL Server 2005 that hasn't gotten a lot of press from what I've read is the new options for the ON DELETE and ON UPDATE clauses: SET NULL and SET DEFAULT. Let's take a look!
2008-08-28
2,984 reads
Avoid Untrusted Constraints in SQL Server
Some time ago, I loaded a large set of data into one my tables. To speed up the load, I disabled the FOREIGN KEY and CHECK constraints on the table and then re-enabled them after the load was complete. I am now finding that some of the loaded data was referentially invalid. What happened?
2008-07-18
3,000 reads
Change column type on constrained columns
Use this proc if you need to alter a column that is part of a primery key
2008-02-04 (first published: 2007-12-10)
1,114 reads
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Query Plan Regressions --
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Question of the Day
Query Plan Regressions --
For the Question of the day, I am going to go deep, but try to be more clear, as I feel like I didn't give enough info last time, leading folks to guess the wrong answer... :) For today's question: You’re troubleshooting a performance issue on a critical stored procedure. You notice that a previously efficient query now performs a full table scan instead of an index seek. Upon investigating, you find that an NVARCHAR parameter is being compared to a VARCHAR column in the WHERE clause. What is the most likely cause of the query plan regression?
See possible answers