Background documentation Catalog cache hitrate Locate the document in its SAP Library structure

Catalog cache hitrate <percentage>%, <number> of <number> accesses failed

Explanation

The hit rate when accessing the Structure linkcatalog cache in which the parsed SQL statements are administered is too low. In a running database application, the catalog cache hit rate should be about 90%. If new program parts or programs are started, the hit rate can sink to a very low level. However, the average over 15 minutes should not be below 85%.

User Response

The size of the catalog cache should be about 100 pages for each database session. You can check this with the Structure linkdatabase parameters MAXUSERTASKS and CAT_CACHE_SUPPLY.

The catalog cache is enlarged dynamically by the active database sessions, and released again with a RELEASE statement. You can determine the current cache sizes with the SQL statement SELECT * FROM CONNECTEDUSERS.

If sessions need significantly more than 100 pages, we recommend that you increase the catalog cache accordingly in the medium term, if the memory of the server is large enough.