Nonstop Database, HiRDB Version 9 System Definition

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2.2.21 Operands related to statistical information

109) pd_statistics = Y | N
Specifies whether collection of the statistics log is to be started at the time of HiRDB startup.
Y:
Begin collecting the statistics log at the time of HiRDB startup.
N:
Do not begin collecting the statistics log at the time of HiRDB startup.
When Y is specified, statistics log information on the system operation of the overall unit only is collected. If information on each server or information other than the statistics information on system operation is needed, the pdstend command must be entered to stop statistical information collection after HiRDB startup has been completed, then the pdstbegin command can be entered to begin collecting statistical information again.
When N is specified, it is still possible to collect a statistics log during HiRDB operation by entering the pdstbegin command.
Notes
The statistics log information cannot be acquired in the following cases:
  • The pdstbegin operand is specified.
  • The standby-less system switchover (1:1) facility is used and the system is switched to an alternate BES unit.
  • A unit to which the standby-less system switchover (effects distributed) facility is applied
  • No server has started in the unit.

110) pd_stj_file_size = maximum-statistics-log-file-size
~<unsigned integer>((64-1000000))<<1024>>(kilobytes)
Specifies in kilobytes the maximum size of a statistics log file.
Two statistics log files are provided. When the amount of stored statistics log information reaches the size specified here, the statistics log files are swapped.
Specification guidelines

111) pd_stj_buff_size = statistics-log-buffer-size
~<unsigned integer>((32-512)) <<32>> (kilobytes)
Specifies the statistics log buffer size.
Specification guidelines
The default value of 32 is appropriate when the following types of statistical information are not to be output:
  • SQL object execution information
  • Statistics about SQL object transmission
If these types of statistical information are to be output, specify the value obtained by adding 32 to the result obtained from the following formula (however, if the result exceeds 512, specify 512):
(a [Figure] 1,024) [Figure] (0.03 [Figure] b)
a: Statistics log output volume (bytes)
For details, see C.1 Formulas for determining size of statistics log file (pd_stj_file_size).
b: Statistical information output time (seconds)

112) pd_sqlobject_stat_timing = deallocate | tran
Specifies the timing for collecting statistics on an SQL object buffer. The following table lists and describes the timing for collecting the statistical information and the statistical information that is collected:
No. Timing for collecting statistical information Statistical information that is collected
deallocate tran
1 When the preprocessing results become invalid if the following SQL statements are executed:
  • DEALLOCATE PREPARE statement
  • PREPARE statement
  • EXECUTE IMMEDIATE statement
 Preprocessing results that are invalidated Preprocessing results that are invalidated
2 When committed Preprocessing results that are invalidated by commit All preprocessing results
3 When rolled back Not collected All preprocessing results
4 When the DISCONNECT statement, COMMIT statement with RELEASE specified, or a definition SQL statement is executed All preprocessing results All preprocessing results
5 When the ROLLBACK statement with RELEASE specified is executed Preprocessing results that are not invalidated by rollback when the ROLLBACK statement with RELEASE specified is executed All preprocessing results
Specification guidelines
Specify tran in the following cases:
  • The preprocessing results become valid beyond the scope of a transaction such as when TRUE is specified for STATEMENT_COMMIT_BEHAVIOR in a holdable cursor or the JDBC driver.
  • The statistics on an SQL object buffer is to be collected during rollback processing.
In any other case, specify deallocate.
Notes
  • When a transaction is decided due to the cancellation of a server process, the statistical information cannot be collected.
  • If TRUE is specified for STATEMENT_COMMIT_BEHAVIOR in a holdable cursor or the JDBC driver, the preprocessing results remain valid beyond the scope of the transaction. Therefore, if deallocate is specified in this operand, the statistics on these SQL object buffers cannot be collected even when the transaction is decided.
  • If TRUE is specified for STATEMENT_COMMIT_BEHAVIOR in a holdable cursor or the JDBC driver, the statistics on an SQL object buffer can be collected only while that cursor is closed.
For details about the holdable cursor and STATEMENT_COMMIT_BEHAVIOR, see the HiRDB Version 9 UAP Development Guide.

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