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PG_DUMP !!!PG_DUMP NAME SYNOPSIS DESCRIPTION DIAGNOSTICS NOTES EXAMPLES HISTORY SEE ALSO ---- !!NAME pg_dump - extract a PostgreSQL database into a script file or other archive file !!SYNOPSIS __pg_dump__ [[ __-a__ | __-s__ ] [[ __-b__ ] [[ __-c__ ] [[ __-C__ ] [[ __-d__ | __-D__ ] [[ __-f__ ''file'' ] [[ __-F__ ''format'' ] [[ __-i__ ] [[ __-n__ | __-N__ ] [[ __-o__ ] [[ __-O__ ] [[ __-R__ ] [[ __-S__ ] [[ __-t__ ''table'' ] [[ __-v__ ] [[ __-x__ ] [[ __-X__ ''keyword'' ] [[ __-Z__ ''0...9'' ] [[ __-h__ ''host'' ] [[ __-p__ ''port'' ] [[ __-U__ ''username'' ] [[ __-W__ ] ''dbname'' !!DESCRIPTION __pg_dump__ is a utility for saving a PostgreSQL database into a script or an archive file. The script files are in plain-text format and contain the SQL commands required to reconstruct the database to the state it was in at the time it was saved. They can be used to reconstruct the database even on other machines and other architectures, with some modifications even on other RDBMS products. Furthermore, there are alternative archive file formats that are meant to be used with pg_restore(1) to rebuild the database, and they also allow __pg_restore__ to be selective about what is restored, or even to reorder the items prior to being restored. The archive files are also designed to be portable across architectures. __pg_dump__ will save the information necessary to re-generate all user-defined types, functions, tables, indexes, aggregates, and operators. In addition, all the data is copied out in text format so that it can be readily copied in again, as well as imported into tools for editing. __pg_dump__ is useful for dumping out the contents of a database to move from one PostgreSQL installation to another. When used with one of the archive file formats and combined with pg_restore(1), __pg_dump__ provides a flexible archival and transfer mechanism. __pg_dump__ can be used to backup an entire database, then __pg_restore__ can be used to examine the archive and/or select which parts of the database are to be restored. The most flexible output file format is the ``custom'' format (__-Fc__). It allows for selection and reordering of all archived items, and is compressed by default. The ''tar'' format (__-Ft__) is not compressed and it is not possible to reorder data when loading, but it is otherwise quite flexible; moreover, it can be manipulated with other tools such as ''tar''. While running __pg_dump__, one should examine the output for any warnings (printed on standard error), especially in light of the limitations listed below. __pg_dump__ makes consistent backups even if the database is being used concurrently. __pg_dump__ does not block other users accessing the database (readers or writers). __OPTIONS__ __pg_dump__ accepts the following command line arguments. (Long option forms are only available on some platforms.) ''dbname'' Specifies the name of the database to be dumped. __-a__ __--data-only__ Dump only the data, not the schema (data definitions). This option is only meaningful for the plain-text format. For the other formats, you may specify the option when you call __pg_restore__. __-b__ __--blobs__ Include large objects in dump. __-c__ __--clean__ Output commands to clean (drop) database objects prior to (the commands for) creating them. This option is only meaningful for the plain-text format. For the other formats, you may specify the option when you call __pg_restore__. __-C__ __--create__ Begin the output with a command to create the database itself and reconnect to the created database. (With a script of this form, it doesn't matter which database you connect to before running the script.) This option is only meaningful for the plain-text format. For the other formats, you may specify the option when you call __pg_restore__. __-d__ __--inserts__ Dump data as __INSERT__ commands (rather than __COPY__). This will make restoration very slow, but it makes the archives more portable to other RDBMS packages. __-D__ __--column-inserts__ __--attribute-inserts__ Dump data as __INSERT__ commands with explicit column names (INSERT INTO ''table'' (''column'', ...) VALUES ...). This will make restoration very slow, but it is necessary if you desire to rearrange column ordering. __-f__ ''file'' __--file=__''file'' Send output to the specified file. If this is omitted, the standard output is used. __-F__ ''format'' __--format=__''format'' Selects the format of the output. ''format'' can be one of the following: __p__ Output a plain-text SQL script file (default) __t__ Output a ''tar'' archive suitable for input into __pg_restore__. Using this archive format allows reordering and/or exclusion of schema elements at the time the database is restored. It is also possible to limit which data is reloaded at restore time. __c__ Output a custom archive suitable for input into __pg_restore__. This is the most flexible format in that it allows reordering of data load as well as schema elements. This format is also compressed by default. __-i__ __--ignore-version__ Ignore version mismatch between __pg_dump__ and the database server. Since __pg_dump__ knows a great deal about system catalogs, any given version of __pg_dump__ is only intended to work with the corresponding release of the database server. Use this option if you need to override the version check (and if __pg_dump__ then fails, don't say you weren't warned). __-n__ __--no-quotes__ Suppress double quotes around identifiers unless absolutely necessary. This may cause trouble loading this dumped data if there are reserved words used for identifiers. This was the default behavior for __pg_dump__ prior to version 6.4. __-N__ __--quotes__ Include double quotes around identifiers. This is the default. __-o__ __--oids__ Dump object identifiers (OIDs) for every table. Use this option if your application references the OID columns in some way (e.g., in a foreign key constraint). Otherwise, this option should not be used. __-O__ __--no-owner__ Do not output commands to set the object ownership to match the original database. Typically, __pg_dump__ issues (__psql__-specific) __connect__ statements to set ownership of schema elements. See also under __-R__ and __-X use-set-session-authorization__. Note that __-O__ does not prevent all reconnections to the database, only the ones that are exclusively used for ownership adjustments. This option is only meaningful for the plain-text format. For the other formats, you may specify the option when you call __pg_restore__. __-R__ __--no-reconnect__ Prohibit __pg_dump__ from outputting a script that would require reconnections to the database while being restored. An average restoration script usually has to reconnect several times as different users to set the original ownerships of the objects. This option is a rather blunt instrument because it makes __pg_dump__ lose this ownership information, __unless__ you use the __-X use-set-session-authorization__ option. One possible reason why reconnections during restore might not be desired is if the access to the database requires manual interaction (e.g., passwords). This option is only meaningful for the plain-text format. For the other formats, you may specify the option when you call __pg_restore__. __-s__ __--schema-only__ Dump only the schema (data definitions), no data. __-S__ ''username'' __--superuser=__''username'' The scripts or archives created by __pg_dump__ need to have superuser access in certain cases, such as when disabling triggers or setting ownership of schema elements. This option specifies the user name to use for those cases. __-t__ ''table'' __--table=__''table'' Dump data for ''table'' only. __-v__ __--verbose__ Specifies verbose mode. __-x__ __--no-privileges__ __--no-acl__ Prevent dumping of access privileges (grant/revoke commands). __-X use-set-session-authorization__ __--use-set-session-authorization__ Normally, if a (plain-text mode) script generated by __pg_dump__ must alter the current database user (e.g., to set correct object ownerships), it uses the psql(1) __connect__ command. This command actually opens a new connection, which might require manual interaction (e.g., passwords). If you use the __-X use-set-session-authorization__ option, then __pg_dump__ will instead output SET SESSION AUTHORIZATION [[__set_session_authorization__(l)] commands. This has the same effect, but it requires that the user restoring the database from the generated script be a database superuser. This option effectively overrides the __-R__ option. Since SET SESSION AUTHORIZATION [[__set_session_authorization__(l)] is a standard SQL command, whereas __connect__ only works in psql(1), this option also enhances the theoretical portability of the output script. This option is only meaningful for the plain-text format. For the other formats, you may specify the option when you call __pg_restore__. __-Z__ ''0..9'' __--compress=__''0..9'' Specify the compression level to use in archive formats that support compression (currently only the custom archive format supports compression). __pg_dump__ also accepts the following command line arguments for connection parameters: __-h__ ''host'' __--host=__''host'' Specifies the host name of the machine on which the server is running. If host begins with a slash, it is used as the directory for the Unix domain socket. __-p__ ''port'' __--port=__''port'' Specifies the Internet TCP/IP port or local Unix domain socket file extension on which the server is listening for connections. The port number defaults to 5432, or the value of the __PGPORT__ environment variable (if set). __-U__ ''username'' Connect as the given user. __-W__ Force a password prompt. This should happen automatically if the server requires password authentication. !!DIAGNOSTICS Connection to database 'template1' failed. connectDBStart() -- connect() failed: No such file or directory Is the postmaster running locally and accepting connections on Unix socket '/tmp/.s.PGSQL.5432'? __pg_dump__ could not attach to the __postmaster__ process on the specified host and port. If you see this message, ensure that the __postmaster__ is running on the proper host and that you have specified the proper port. __Note: pg_dump__ internally executes __SELECT__ statements. If you have problems running __pg_dump__, make sure you are able to select information from the database using, for example, psql(1). !!NOTES If your installation has any local additions to the template1 database, be careful to restore the output of __pg_dump__ into a truly empty database; otherwise you are likely to get errors due to duplicate definitions of the added objects. To make an empty database without any local additions, copy from template0 not template1, for example: CREATE DATABASE foo WITH TEMPLATE = template0; __pg_dump__ has a few limitations: When dumping a single table or as plain text, __pg_dump__ does not handle large objects. Large objects must be dumped in their entirety using one of the binary archive formats. When doing a data only dump, __pg_dump__ emits queries to disable triggers on user tables before inserting the data and queries to re-enable them after the data has been inserted. If the restore is stopped in the middle, the system catalogs may be left in the wrong state. !!EXAMPLES To dump a database: $ __pg_dump mydb __To reload this database: $ __psql -d database -f db.out __To dump a database called mydb that contains large objects to a ''tar'' file: $ __pg_dump -Ft -b mydb __To reload this database (with large objects) to an existing database called newdb: $ __pg_restore -d newdb db.tar __ !!HISTORY The __pg_dump__ utility first appeared in __Postgres95__ release 0.02. The non-plain-text output formats were introduced in __PostgreSQL__ release 7.1. !!SEE ALSO pg_dumpall(1), __pg_restore__(1), psql(1), ''PostgreSQL Administrator's Guide'' ----
4 pages link to
pg_dump(1)
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pg_dumpall(1)
pg_restore(1)
pg_wrapper(1)
Man1p
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