wal_log_hints
A configuration parameter determining whether the entire content of each disk page is written to WAL during the first modification of that page after a checkpoint
wal_log_hints
is a configuration parameter determining whether the entire content of each disk page is written to WAL during the first modification of that page after a checkpoint.
wal_log_hints
was added in PostgreSQL 9.4.
Default value
The default value for wal_log_hints
is: off
.
Usage
wal_log_hints
has the same performance impact as enabling data page checksums
. As the latter can only be enabled when a cluster is set up with initdb
, it provides a way of testing for performance impacts without setting up a new cluster.
If pg_rewind
is intended to be used, and data page checksums
are not enabled, wal_log_hints
must be set to on
.
The current value of wal_log_hints
is one of the configuration parameters recorded in pg_control
.
Change history
References
- PostgreSQL documentation: wal_log_hints