Documentazione di PostgreSQL 9.0 > Amministrazione del server > Recovery Configuration
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26. Recovery Configuration

This chapter describes the settings available in the recovery.conf file. They apply only for the duration of the recovery. They must be reset for any subsequent recovery you wish to perform. They cannot be changed once recovery has begun.

Settings in recovery.conf are specified in the format name = 'value'. One parameter is specified per line. Hash marks (#) designate the rest of the line as a comment. To embed a single quote in a parameter value, write two quotes ('').

A sample file, share/recovery.conf.sample, is provided in the installation's share/ directory.

26.1. Archive recovery settings

restore_command (string)

The shell command to execute to retrieve an archived segment of the WAL file series. This parameter is required for archive recovery, but optional for streaming replication. Any %f in the string is replaced by the name of the file to retrieve from the archive, and any %p is replaced by the copy destination path name on the server. (The path name is relative to the current working directory, i.e., the cluster's data directory.) Any %r is replaced by the name of the file containing the last valid restart point. That is the earliest file that must be kept to allow a restore to be restartable, so this information can be used to truncate the archive to just the minimum required to support restarting from the current restore. %r is typically only used by warm-standby configurations (see Sezione 25.2, «Log-Shipping Standby Servers»). Write %% to embed an actual % character.

It is important for the command to return a zero exit status only if it succeeds. The command will be asked for file names that are not present in the archive; it must return nonzero when so asked. Examples:

restore_command = 'cp /mnt/server/archivedir/%f "%p"'
restore_command = 'copy "C:\\server\\archivedir\\%f" "%p"'  # Windows

archive_cleanup_command (string)

This parameter specifies a shell command that will be executed at every restartpoint. This parameter is optional. The purpose of the archive_cleanup_command is to provide a mechanism for cleaning up old archived WAL files that are no longer needed by the standby server. Any %r is replaced by the name of the file containing the last valid restart point. That is the earliest file that must be kept to allow a restore to be restartable, so this information can be used to truncate the archive to just the minimum required to support restart from the current restore. %r would typically be used in a warm-standby configuration (see Sezione 25.2, «Log-Shipping Standby Servers»). Write %% to embed an actual % character in the command.

If the command returns a non-zero exit status then a WARNING log message will be written.

recovery_end_command (string)

This parameter specifies a shell command that will be executed once only at the end of recovery. This parameter is optional. The purpose of the recovery_end_command is to provide a mechanism for cleanup following replication or recovery. Any %r is replaced by the name of the file containing the last valid restart point, like in archive_cleanup_command.

If the command returns a non-zero exit status then a WARNING log message will be written and the database will proceed to start up anyway. An exception is that if the command was terminated by a signal, the database will not proceed with startup.

Documentazione di PostgreSQL 9.0 > Amministrazione del server > Recovery Configuration
PrecedenteHot StandbyRecovery target settingsSuccessivo