UDR cache

When any session requires the use of an SPL routine for the first time, the database server reads the system catalog tables to retrieve the code for the SPL routine. The database server converts the p-code to an executable form. The database server caches this executable form of the SPL routine in the virtual portion of shared memory.

The database server keeps the executable format of an SPL routine in the UDR cache on a most recently used basis.

You can monitor the UDR cache with the -g prc option of the onstat utility. For more information about onstat -g prc and adjusting the size of the UDR cache with the PC_POOLSIZE configuration parameter, refer to the Informix® Performance Guide.