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• Database Programming
• Defensive programming
• Transact SQL

• Defensive database programming: eliminating IF statements.

  The following pattern is quite common in database programming: IF EXISTS(some query) BEGIN DO SOMETHING; END When such code runs in high concurrency situations, it may not work as expected. I will provide a repro when such logic fails 40% of the time. Read More... Posted Thursday, November 27, 2008 6:27 PM by Alexander Kuznetsov | 13 Comments Filed under: SQL Server, SQL, Database Programming, Transact SQL, Defensive programming

• Performance of inserts and IGNORE_DUP_KEY

  If your data has a small percentage of duplicates, then IGNORE_DUP_KEY may speed up your inserts. For larger amounts of duplicates, IGNORE_DUP_KEY may slow them down significantly. I set up two tables, stripping down all the irrelevant details, as follows: Read More... Posted Wednesday, July 30, 2008 10:39 PM by Alexander Kuznetsov | 0 Comments Filed under: SQL Server, SQL, Database Programming