From 2176da70f84d89208eabe9094d20e9a8edd1b8a6 Mon Sep 17 00:00:00 2001 From: Fujii Masao Date: Fri, 11 Sep 2015 13:02:15 +0900 Subject: [PATCH] Correct description of PageHeaderData layout in documentation Back-patch to 9.3 where PageHeaderData layout was changed. Michael Paquier --- doc/src/sgml/storage.sgml | 26 +++++++++++++------------- 1 file changed, 13 insertions(+), 13 deletions(-) diff --git a/doc/src/sgml/storage.sgml b/doc/src/sgml/storage.sgml index 8d9610e7040..fd31b73b626 100644 --- a/doc/src/sgml/storage.sgml +++ b/doc/src/sgml/storage.sgml @@ -625,18 +625,18 @@ data. Empty in ordinary tables. The first 24 bytes of each page consists of a page header - (PageHeaderData). Its format is detailed in . The first two fields track the most - recent WAL entry related to this page. Next is a 2-byte field - containing flag bits. This is followed by three 2-byte integer fields - (pd_lower, pd_upper, - and pd_special). These contain byte offsets - from the page start to the start - of unallocated space, to the end of unallocated space, and to the start of - the special space. - The next 2 bytes of the page header, - pd_pagesize_version, store both the page size - and a version indicator. Beginning with + (PageHeaderData). Its format is detailed in . The first field tracks the most + recent WAL entry related to this page. The second field contains + the page checksum if are + enabled. Next is a 2-byte field containing flag bits. This is followed + by three 2-byte integer fields (pd_lower, + pd_upper, and + pd_special). These contain byte offsets + from the page start to the start of unallocated space, to the end of + unallocated space, and to the start of the special space. The next 2 + bytes of the page header, pd_pagesize_version, + store both the page size and a version indicator. Beginning with PostgreSQL 8.3 the version number is 4; PostgreSQL 8.1 and 8.2 used version number 3; PostgreSQL 8.0 used version number 2; @@ -666,7 +666,7 @@ data. Empty in ordinary tables. pd_lsn - XLogRecPtr + PageXLogRecPtr 8 bytes LSN: next byte after last byte of xlog record for last change to this page