Description
Write-Ahead Logging (WAL) puts a checkpoint in the transaction log
every so often. (To adjust the automatic checkpoint interval, see
the run-time configuration options checkpoint_segments
and checkpoint_timeout.) The
CHECKPOINT command forces an immediate
checkpoint when the command is issued, without waiting for a
scheduled checkpoint.
A checkpoint is a point in the transaction log sequence at which
all data files have been updated to reflect the information in the
log. All data files will be flushed to disk. Refer to
Chapter 29 for more information about the WAL system.
If executed during recovery, the CHECKPOINT command
will force a restartpoint rather than writing a new checkpoint.
Only superusers can call CHECKPOINT. The command is
not intended for use during normal operation.