Snapshot Information Level Database Application |
API Structure(s) sqlm_dbase sqlm_appl |
Monitor Group Basic Basic |
Resettable |
Yes |
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Event Information Level Database Connection |
API Structure(s) sqlm_db_event sqlm_conn_event |
|
API Element Name Element Type |
cat_cache_overflows counter |
Description: The number of times that an insert into the catalog cache failed due the catalog cache being full.
Usage: The catalog cache space is filled with table descriptor information.
The cache entries for transactions that compile SQL statements, either by issuing dynamic SQL statements or by binding a package, will not be eligible to be removed from the cache until that transaction has either been committed or rolled back. Catalog cache space is reclaimed by evicting table descriptor information for tables, views, or aliases that are not currently in use by any transaction. Once a transaction has experienced a catalog cache overflow, all subsequent attempts by the same transaction to insert table descriptor information into the catalog cache will report an overflow.
If catalog cache overflows is large, the catalog cache may be too small for the workload. Enlarging the catalog cache may improve its performance. If the workload includes transactions which compile a large number of SQL statements referencing many tables, views, and aliases in a single unit of work, or if it includes binding of packages containing many SQL statements referencing many tables, views or aliases, compiling fewer SQL statements in a single transaction or splitting packages so that they include fewer SQL statement may improve the performance of the catalog cache.
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