DB2 10.5 for Linux, UNIX, and Windows

audit_buf_sz - Audit buffer size configuration parameter

This parameter specifies the size of the buffers used when you audit the DB2® instance.

Configuration type
Database manager
Applies to
  • Database server with local and remote clients
  • Database server with local clients
  • Partitioned database server with local and remote clients
Parameter type
Configurable
Default [range]
0 [0 - 65 000]
Unit of measure
Pages (4 KB)
When allocated
Two buffers are allocated from the DBMS memory set when the DB2 instance is started. Two buffers are allocated from the database heap for each database that is activated.
When freed
Instance-level audit buffers are freed when DB2 is stopped. Database-level audit buffers are freed when the database is deactivated.

If you set the value of audit_buf_sz configuration parameter to zero (0), audit buffers are not used. If you set the value greater than zero (0), space is allocated for the audit buffers where the audit records are placed when they are generated by the audit facility. The amount of space allocated for each audit buffer is the value of audit_buf_sz times the page size of 4KB. At regular time intervals, or when an audit buffer is full, the db2auditd audit daemon process flushes the audit buffer to disk.

Audit buffers cannot be allocated dynamically. You must restart the DB2 instance before the new value for this parameter takes effect.

If you change audit_buf_sz configuration parameter to a value larger than zero (0), the audit facility writes records to disk asynchronously compared to the execution of the statements generating the audit records, which improves the performance of the DB2 instance. The value of zero (0) means the audit facility writes records to disk synchronously with the execution of the statements generating the audit records. The synchronous operation during auditing decreases the performance of applications running in DB2.