Catalog cache hitrate <percentage>%, <number> of <number> accesses failed
The hit rate when
accessing the catalog 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 components or programs are started,
the hit rate can drop temporarily to a very low level. However, the average over a 15-minute period should
not drop below 85%.
The size of the
catalog cache should be about 100 pages for each database session.
You can check this using the general database
parameter MAXUSERTASKS and the
special database
parameter 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 using the SQL statement SELECT * FROM CONNECTEDUSERS.
If sessions need significantly more than 100 pages, we recommend that in the medium term you increase the catalog cache accordingly, memory permitted.