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.

The default is on, the same behaviour as in previous PostgreSQL versions, ensuring file space is allocated before WAL records are written. 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.

wal_init_zero was added in PostgreSQL 12 (commit 475861b2).

Categories

GUC configuration item, Performance, WAL

See also

wal_recycle