21.5.1 Tuning the buffer length for table definition information

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 hits rate with the following formula, and make changes to the definitions so that the hits rate becomes greater than 80%:
Table definition information buffer hits rate (%) =
(table definition information buffer hits count[Figure] number of table definition information acquisition requests)[Figure] 100
Actions to be taken
Increase the value of the pd_table_def_cache_size operand.