Notes on pg_dump
================
1. pg_dump, by default, still outputs text files.
2. pg_dumpall forces all pg_dump output to be text, since it also outputs text into the same output stream.
3. The plain text output format can not be used as input into pg_restore.
4. pg_dump now dumps the items in a modified OID order to try to improve relaibility of default restores.
To dump a database into the next custom format, type:
pg_dump <db-name> -Fc > <backup-file>
or, in TAR format
pg_dump <db-name> -Ft > <backup-file>
To restore, try
To list contents:
pg_restore -l <backup-file> | less
or to list tables:
pg_restore <backup-file> --table | less
or to list in a differnet orderL
pg_restore <backup-file> -l --oid --rearrange | less
Once you are happy with the list, just remove the '-l', and an SQL script will be output.
You can also dump a listing:
pg_restore -l <backup-file> > toc.lis
or
pg_restore -l <backup-file> -f toc.lis
edit it, and rearrange the lines (or delete some):
vi toc.lis
then use it to restore selected items:
pg_restore <backup-file> --use=toc.lis -l | less
When you like the list, type
pg_restore backup.bck --use=toc.lis > script.sql
or, simply:
createdb newdbname
pg_restore backup.bck --use=toc.lis | psql newdbname
BLOBs
=====
To dump blobs you must use the custom archive format (-Fc) or TAR format (-Ft), and specify the
--blobs qualifier to the pg_dump command.
To restore blobs you must use a direct database connection (--db=db-to-restore-to).
eg.
pg_dump --blob -Fc db-to-backup -f backup.bck
pg_restore backup.bck --db=db-to-restore-into
TAR
===
The TAR archive that pg_dump creates currently has a blank username & group for the files,
but should be otherwise valid. It also includes a 'restore.sql' script which is there for
the benefit of humans. It is never used by pg_restore.
Note: the TAR format archive can only be used as input into pg_restore if it is in TAR form.
(ie. you should not extract the files then expect pg_restore to work).
You can extract, edit, and tar the files again, and it should work, but the 'toc'
file should go at the start, the data files be in the order they are used, and
the BLOB files at the end.
Philip Warner, 16-Jul-2000
pjw@rhyme.com.au
424f0edcb8