21.5.3 Tuning the buffer length for user privilege information

This section explains tuning of the buffer length for user privilege information (pd_auth_cache_size operand value).

Information to be referenced
See the following system activity statistical information provided by the statistics analysis utility:
  • User privilege information buffer hits count (#OF CON/DBA CACHE HIT)
  • Number of user privilege information acquisition requests (#OF CON/DBA DEF GET REQ)
Tuning procedure
If the user privilege information buffer hits rate is low for the table definition information buffer hits rate, performance may be affected adversely for the following reason:
  • The user privilege information buffer hits rate is low because there is too much CONNECT and DBA privilege information.
Obtain the user privilege information buffer hits rate with the following formula:
User privilege information buffer hits rate (%) =
(user privilege information buffer hits count[Figure] number of user privilege information acquisition requests)[Figure] 100
Actions to be taken
Increase the value of the pd_auth_cache_size operand.