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SQL Server Fast Forward Cursors

- 1 answer

It is generally accepted that the use of cursors in stored procedures should be avoided where possible (replaced with set based logic etc). If you take the cases where you need to iterate over some data, and can do in a read only manner, are fast forward (read only forward) cursor more or less inefficient than say while loops? From my investigations it looks as though the cursor option is generally faster and uses less reads and cpu time. I haven't done any extensive testing, but is this what others find? Do cursors of this type (fast forward) carry additional overhead or resource that could be expensive that I don't know about.

Is all the talk about not using cursors really about avoiding the use of cursors when set-based approaches are available, and the use of updatable cursors etc.

Thanks

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Answer

The 'Best Practice' of avoiding cursors in SQL Server dates back to SQL Server 2000 and earlier versions. The rewrite of the engine in SQL 2005 addressed most of the issues related to the problems of cursors, particularly with the introduction of the fast forward option. Cursors are not neccessarily worse than set-based and are used extensively and successfully in Oracle PL/SQL (LOOP).

The 'generally accepted' that you refer to was valid, but is now outdated and incorrect - go on the assumption that fast forward cursors behave as advertised and perform. Do some tests and research, basing your findings on SQL2005 and later

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source: stackoverflow.com
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