This section explains tuning the buffer length for table definition information (pd_table_def_cache_size operand value).

Information to be referenced

See the following system activity statistical information provided by the statistics analysis utility:

• Table definition information buffer hits count (#OF TBL-CACHE HIT)
• Number of table definition information acquisition requests (#OF TBL-DEF GET REQ)

Tuning procedure

Obtain the table definition information buffer hit rate with the following formula, and make changes to the definitions so that the hit rate becomes greater than 80%:

Table definition information buffer hit rate (%) =

(table definition information buffer hits count^# number of table definition information acquisition requests^#) 100

#: If a sequence generator is used it is also included.

Actions to be taken

Increase the value of the pd_table_def_cache_size operand.