wal_log_hints
A GUC 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 GUC 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 GUC configuration parameters recorded in pg_control.
Change history
References
- PostgreSQL documentation: wal_log_hints