Applications move log records to the log output buffer using two methods:
Moves the log record to the output buffer and returns control to the application. If there are no output buffers available, the application will wait and the statistics report UNAVAILABLE ACTIVE LOG BUFF will have a non-zero value. These results mean that DB2 had to wait to externalize log records because no output log buffers were available. Successful moves without a wait are recorded in the statistics report under NO WAIT requests.
Occurs at commit time and the application waits during this process, which is considered a synchronous write.
Log records are then written from the output buffers to the active log data sets on the disk either synchronously or asynchronously. The WRITE OUTPUT LOG BUFFERS in the statistics report contains information about the write operation.
To improve the performance of the log writes, you can increase the number of output buffers available for writing active log data sets that are performed by changing an installation parameter OUTBUFF.
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