From d755688f2429b7db6031818b39a17a5ba813fe1d Mon Sep 17 00:00:00 2001 From: Bruce Momjian Date: Mon, 18 Apr 2005 01:29:00 +0000 Subject: [PATCH] Update PITR mention of which WAL files are needed. --- doc/src/sgml/backup.sgml | 43 ++++++++++++++++++++++++---------------- 1 file changed, 26 insertions(+), 17 deletions(-) diff --git a/doc/src/sgml/backup.sgml b/doc/src/sgml/backup.sgml index c02d2ef321..8cf1ee377c 100644 --- a/doc/src/sgml/backup.sgml +++ b/doc/src/sgml/backup.sgml @@ -1,5 +1,5 @@ Backup and Restore @@ -724,23 +724,32 @@ SELECT pg_stop_backup(); To make use of this backup, you will need to keep around all the WAL - segment files generated at or after the starting time of the backup. + segment files generated during and after the file system backup. To aid you in doing this, the pg_stop_backup function - creates a backup history file that is immediately stored - into the WAL archive area. This file is named after the first WAL - segment file that you need to have to make use of the backup. For - example, if the starting WAL file is 0000000100001234000055CD - the backup history file will be named something like - 0000000100001234000055CD.007C9330.backup. (The second part of - this file name stands for an exact position within the WAL file, and can - ordinarily be ignored.) Once you have safely archived this WAL - segment file, you can delete all archived WAL segments with names numerically - preceding this one. The backup history file is just a small text file. - It contains the label string you gave to pg_start_backup, as - well as the starting and ending times of the backup. If you used the - label to identify where the associated dump file is kept, then the - archived history file is enough to tell you which dump file to restore, - should you need to do so. + creates a backup history file that is immediately + stored into the WAL archive area. This file is named after the first + WAL segment file that you need to have to make use of the backup. + For example, if the starting WAL file is + 0000000100001234000055CD the backup history file will be + named something like + 0000000100001234000055CD.007C9330.backup. (The second + number in the file name stands for an exact position within the WAL + file, and can ordinarily be ignored.) Once you have safely archived + the WAL segment files used during the file system backup (as + specified in the backup history file), you can delete all archived + WAL segments with names numerically less. Keep in mind that only + completed WAL segment files are archived, so there will be delay + between running pg_stop_backup and the archiving of + all WAL segment files needed to make the file system backup + consistent. + + + The backup history file is just a small text file. It contains the + label string you gave to pg_start_backup, as well as + the starting and ending times of the backup. If you used the label + to identify where the associated dump file is kept, then the + archived history file is enough to tell you which dump file to + restore, should you need to do so.