pg_checksums

Enables, disables, or checks data checksums in a Cloudberry Database cluster.

Synopsis

pg_checksums [<option> ...] [-D <datadir> | --pgdata=<datadir>]

pg_checksums -? | --help

pg_checksums -V | --version

Description

pg_checksums is a standard PostgreSQL utility that you can use to check, enable, or disable data checksums in a Cloudberry Database cluster. The server must be shut down cleanly before running pg_checksums. When verifying checksums, Cloudberry Database returns the exit status zero if there are no checksum errors, and returns nonzero if it detects at least one checksum failure. When enabling or disabling checksums, Cloudberry returns a nonzero exit status if the operation failed.

When verifying checksums, Cloudberry Database scans every file in the cluster. When enabling checksums, every file in the cluster is rewritten in-place. Disabling checksums only updates the pg_control file.

Options

The following command-line options are available:

-D datadir
--pgdata=datadir

Specifies the directory where the database cluster is stored.

-c
--check

Checks checksums. This is the default mode when no other options are specified.

-d
--disable

Deactivates checksums.

-e
--enable

Activates checksums.

-f fnode
--filenode=fnode

Only validate checksums in the relation with filenode fnode.

-N
--no-sync

By default, pg_checksums waits for all files to be written safely to disk. This option causes pg_checksums to return without waiting, which is faster, but a subsequent operating system crash could leave the updated data directory corrupt. This option has no effect when specified with --check.

Note While useful for testing, do not use the -N/--nosync option in a production installation.

-P
--progress

Enables progress reporting. Turning this on will deliver a progress report while checking or enabling checksums.

-v
--verbose

Specifies verbose mode, which lists all checked files.

-V
--version

Print the pg_checksums version, and exit.

-?
--help

Show help about pg_checksums command line arguments, and exit.

Environment

PGDATA

Specifies the directory where the database cluster is stored; you can specify the -D option to the pg_checksums command to override this setting.

PG_COLOR

Specifies whether to use color in diagnostic messages. Possible values are always, auto, and never.

Notes

Enabling checksums in a large cluster can potentially take a long time. To guard against data loss during this operation, you must not start the cluster, nor start other programs that write to the data directory.

If pg_checksums is aborted or killed while enabling or disabling checksums, the cluster's data checksum configuration remains unchanged; you can re-run pg_checksums to perform the same operation.