BUG: SQL Server Books Online Incorrectly States That the Age Field of a Query Plan Is Incremented by Compilation Cost Factor (825728)
The information in this article applies to:
- Microsoft SQL Server 2000 (all editions)
SYMPTOMS The "Aging Execution Plans" section in the "Execution Plan Caching and Reuse" topic of SQL Server Books Online incorrectly states that each time a query plan that resides in the procedure
cache is referenced by a connection, the age field of the query plan object is
incremented by the compilation cost factor. STATUS
Microsoft has confirmed that this is a bug in the Microsoft products that are
listed at the beginning of this article.
MORE INFORMATIONThe "Aging Execution Plans" section states that Microsoft SQL Server 2000 ages old,
unused execution plans out of the procedure cache when space is required. Each
query plan and execution context has an associated cost factor that indicates
how expensive the structure is to compile. These data structures also have an
age field. The "Aging Execution Plans" section then incorrectly states that each time the object is
referenced by a connection the age field is incremented by the compilation
cost factor.
However, when the object is referenced by a connection,
SQL Server 2000 resets the age factor of a query plan to the cost factor. For
example, if a query plan has a cost factor of 8, the age factor of the query
plan is reset to 8 every time the query plan referenced for reuse. Therefore, even
though the query is referenced two times, the age factor is set to
8.
| Modification Type: | Major | Last Reviewed: | 11/26/2003 |
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| Keywords: | kbBug kbCaching kbQuery kbStoredProc kbhelpfile KB825728 kbAudDeveloper |
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