A configuration parameter determining how much WAL to prefetch in advance

wal_decode_buffer_size is a configuration parameter which, if WAL prefetching is enabled, determines how far ahead a standby can look in the WAL to find blocks to prefetch.

wal_decode_buffer_size was added in PostgreSQL 15.

Default value

The default value for wal_decode_buffer_size is: 512kB.

Change history

Note that  was originally added in PostgreSQL 14 (commit 1d257577) but subsequently withdrawn (commit c2dc1934).


GUC configuration item, Replication, WAL

See also

recovery_prefetch, recovery_prefetch_fpw, pg_stat_recovery_prefetch