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<chapter id="backup">

<title>Backup and Restore</title>

<literal>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 file system backup and the WAL segment files used during the

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 <function>pg_stop_backup</> and the archiving of

all WAL segment files needed to make the file system backup

consistent.

the file system backup and the WAL segment files used during the

backup (as specified in the backup history file), all archived WAL

segments with names numerically less are no longer needed to recover

the file system backup and may be deleted. However, you should

consider keeping several backup sets to be absolutely certain that

you are can recover your data. Keep in mind that only completed WAL

segment files are archived, so there will be delay between running

<function>pg_stop_backup</> and the archiving of all WAL segment

files needed to make the file system backup consistent.

</para>

<para>

The backup history file is just a small text file. It contains the