What you need to know about calling functions from SQL

Tom Kyte:

When calling functions from SQL, you had better not rely on how often the functions get called, in what order, or whatever. In short, assume nothing. And remember – SQL rewrites kick in and we rewrite your SQL all of the time. Don’t rely on side effects.

Related articles:

• User-Defined Aggregate Functions
• ANY Types, Pipelined Table Functions, Dynamic SQL and Pivot
• Keep first, Keep last

Filed in Oracle, Tips on 15 Mar 11 | Tags: sql

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