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PostgreSQL documentation

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</title>

<para>

<application>pg_dump</application> is a utility for saving a

<productname>PostgreSQL</productname> 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. To restore these

scripts, use <xref linkend="app-psql">. They can be used to

reconstruct the database even on other machines and other

architectures, with some modifications even on other SQL database

products.

<application>pg_dump</application> is a utility for backing up a

<productname>PostgreSQL</productname> database. It makes consistent

backups even if the database is being used concurrently.

<application>pg_dump</application> does not block other users

accessing the database (readers or writers).

</para>

<para>

Furthermore, there are alternative archive file formats

that are meant to be used with <xref linkend="app-pgrestore"> to

rebuild the database, and they also allow

<application>pg_restore</application> 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

Dumps can be output in script or archive file formats. 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. To restore these scripts, use <xref linkend="app-psql">. They

can be used to reconstruct the database even on other machines and

other architectures, with some modifications even on other SQL

database products.

</para>

<para>

The alternative archive file formats that are meant to be used with

<xref linkend="app-pgrestore"> to rebuild the database, and they also

allow <application>pg_restore</application> 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.

</para>

<para>

When used with one of the archive file formats and combined with

<application>pg_restore</application>, <application>pg_dump</application> provides a

flexible archival and

<application>pg_restore</application>,

<application>pg_dump</application> provides aflexible archival and

transfer mechanism. <application>pg_dump</application> can be used to

backup an entire database, then <application>pg_restore</application> 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 isthe <quote>custom</quote>

format (<option>-Fc</option>). It allows for selectionand

reordering of all archived items, and is compressedby default. The

<application>tar</application> format(<option>-Ft</option>) is not

compressed and it is not possible toreorder data when loading, but

it is otherwise quite flexible;moreover, it can be manipulated with

other tools such as<command>tar</command>.

backup an entire database, then <application>pg_restore</application>

canbe 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 <quote>custom</quote> format (<option>-Fc</option>). It allows

for selection and reordering of all archived items,and is compressed

by default. The <application>tar</application> format

(<option>-Ft</option>) 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

<command>tar</command>.

</para>

<para>

light of the limitations listed below.

</para>

<para>

<application>pg_dump</application> makes consistent backups even if the

database is being used concurrently. <application>pg_dump</application>

does not block other users accessing the database (readers or

writers).

</para>

</refsect1>

<refsect1 id="pg-dump-options">