Release 10.1A: OpenEdge Data Management:
Database Administration

Page Writers

Displays information about asynchronous page writer (APW) activity. Figure 19–34 shows a sample Page Writers Activity display.

09/26/03             Activity: Page Writers 16:29                from 09/25/03 13:56 to 09/26/03 11:23 (21 hrs 27 min)                                     Total   Per Min   Per Sec    Per Tx Total DB writes                     3       0         0.00       0.00 APW DB writes                       0       0         0.00       0.00     scan writes                     8       25        0.42       0.00     APW queue writes                2       6         0.10       0.00     ckp queue writes                0       0         0.00       0.00     scan cycles                     0       0         0.00       0.00     buffers scanned                 0       0         0.00       0.00     bufs checkpointed               173     0         0.11       0.14 Checkpoints                         8211    0         5.22       6.79 Marked at checkpoint                0       0         0.00       0.00 Flushed at checkpoint               0       0         0.00       0.00 Number of APWs:                      1

Figure 19–34: PROMON Page Writers Activity display

The display lists the following types of APW operations:

Total DB writes — The total number of database write operations performed by all processes.
APW DB writes — The number of database write operations performed by the APW. This is a subset of the total number of DB writes:
Scan writes — The number of buffers written during the scan cycle.
APW queue writes — The number of buffers written to clear the APW queue.
Ckp queue writes — The number of buffers written from the checkpoint queue.
Scan cycles — The number of scan cycles. During a scan cycle, the APW scans a portion of the buffer pool to look for modified buffers.
Buffers scanned — The number of buffers scanned during each cycle.
Bufs checkpointed — The number of buffers checkpointed.
Checkpoints — The number of checkpoints that have occurred.
Marked at checkpoint — The number of buffers that were scheduled to be written before the end of the checkpoint.
Flushed at checkpoint — The number of blocks that were not written during the checkpoint and had to be written all at once at the end of the checkpoint.
Number of APWs — The number of APWs running.