The CA-IDMS SQL Option, when executing queries, may need to temporarily store the result of an SQL query for various processing before passing the response to the calling program. Where is this information stored?
CA IDMS - all supported releases.
If the SQL Option needs to perform large scale operations on the data which constitutes the result of an SQL query, it will first store this data in the scratch area (SYSTEM.DDLDCSCR). Note that SQL does not always need to do this. Mostly it will use the scratch area for performing large sorts, but if there is an index on the data which supports the ORDER BY clause on the query, this may not be necessary.
If you are starting to use SQL, it would be a good idea to monitor and eventually increase the SYSTEM.DDLSCSCR area (or the SCRATCH IN XA specification in the SYSTEM statement of System Generation if that is being used).
The SQL Option will also use the scratch area for storing TEMPORARY TABLES.