wal_init_zero
A configuration parameter determining whether new WAL files should be filled with zeroes
wal_init_zero is configuration parameter determining whether new WAL files should be filled with zeroes.
wal_init_zero was added in PostgreSQL 12 (commit 475861b2).
Default value
The default value for wal_init_zero is: on.
Usage
If set to on (the default), new WAL files will be fillzed with zeroes, ensuring file space is allocated before WAL records are written. This is the same behaviour as in previous PostgreSQL versions,
If set to off, only the final byte is written when the file is created, which saves unnecessary work on "Copy-On-Write" (CoW) filesystems.
References
- PostgreSQL documentation: wal_init_zero