Page writer activity (_ActPWs)

The _ActPWs VST displays information about asynchronous page writer (APW) activity, including the number of APW queue and database writes, checkpoint and scan writes, total database writes; the number of buffers scanned and checkpointed; the number of checkpoints, checkpoint flushes, and marks; the number of scan cycles, committed transactions, and database up time.

Field name Data type Description
_PW-ApwQWrites INT64 Number of buffers written to clear the APW queue
_PW-BuffsScaned INT64 Number of buffers scanned during each cycle
_PW-BufsCkp INT64 Number of buffers checkpointed
_PW-Checkpoints INT64 Number of checkpoints that have occurred
_PW-CkpQWrites INT64 Number of buffers written from the checkpoint queue
_PW-DBWrites INT64 Number of database write operations performed by the APW
_PW-Flushed INT64 Number of blocks that were not written during the checkpoint and had to be written all at once at the end of the checkpoint
_PW-Marked INT64 Number of buffers that were scheduled to be written before the end of the checkpoint
_PW-ScanCycles INT64 Number of scan cycles. During a scan cycle, the APW scans a portion of the buffer pool to look for modified buffers
_PW-ScanWrites INT64 Number of buffers written during the scan cycle
_PW-TotDBWrites INT64 Total number of database write operations performed by all processes
_PW-Trans INT64 Number of transactions committed
_PW-UpTime INTEGER Number of seconds the database was up