diff options
Diffstat (limited to 'doc/src')
| -rw-r--r-- | doc/src/sgml/wal.sgml | 10 |
1 files changed, 6 insertions, 4 deletions
diff --git a/doc/src/sgml/wal.sgml b/doc/src/sgml/wal.sgml index b44a6257ecc..10ce786f152 100644 --- a/doc/src/sgml/wal.sgml +++ b/doc/src/sgml/wal.sgml @@ -167,10 +167,12 @@ <productname>PostgreSQL</> periodically writes full page images to permanent WAL storage <emphasis>before</> modifying the actual page on disk. By doing this, during crash recovery <productname>PostgreSQL</> can - restore partially-written pages from WAL. If you have a battery-backed disk - controller or file-system software that prevents partial page writes - (e.g., ZFS), you can safely turn off this page imaging by turning off the - <xref linkend="guc-full-page-writes"> parameter. + restore partially-written pages from WAL. If you have file-system software + that prevents partial page writes (e.g., ZFS), you can turn off + this page imaging by turning off the <xref + linkend="guc-full-page-writes"> parameter. Battery-Backed Unit + (BBU) disk controllers do not prevent partial page writes unless + they guarantee that data is written to the BBU as full (8kB) pages. </para> </sect1> |