1PG_DUMP(1) PostgreSQL 14.3 Documentation PG_DUMP(1)
2
6 pg_dump - extract a PostgreSQL database into a script file or other
7 archive file
8
10 pg_dump [connection-option...] [option...] [dbname]
11
13 pg_dump is a utility for backing up a PostgreSQL database. It makes
14 consistent backups even if the database is being used concurrently.
15 pg_dump does not block other users accessing the database (readers or
16 writers).
17 pg_dump only dumps a single database. To back up an entire cluster, or
19 to back up global objects that are common to all databases in a cluster
20 (such as roles and tablespaces), use pg_dumpall(1).
21 Dumps can be output in script or archive file formats. Script dumps are
23 plain-text files containing the SQL commands required to reconstruct
24 the database to the state it was in at the time it was saved. To
25 restore from such a script, feed it to psql(1). Script files can be
26 used to reconstruct the database even on other machines and other
27 architectures; with some modifications, even on other SQL database
28 products.
29 The alternative archive file formats must be used with pg_restore(1) to
31 rebuild the database. They allow pg_restore to be selective about what
32 is restored, or even to reorder the items prior to being restored. The
33 archive file formats are designed to be portable across architectures.
34 When used with one of the archive file formats and combined with
36 pg_restore, pg_dump provides a flexible archival and transfer
37 mechanism. pg_dump can be used to backup an entire database, then
38 pg_restore can be used to examine the archive and/or select which parts
39 of the database are to be restored. The most flexible output file
40 formats are the “custom” format (-Fc) and the “directory” format (-Fd).
41 They allow for selection and reordering of all archived items, support
42 parallel restoration, and are compressed by default. The “directory”
43 format is the only format that supports parallel dumps.
44 While running pg_dump, one should examine the output for any warnings
46 (printed on standard error), especially in light of the limitations
47 listed below.
48
50 The following command-line options control the content and format of
51 the output.
52 dbname
54 Specifies the name of the database to be dumped. If this is not
55 specified, the environment variable PGDATABASE is used. If that is
56 not set, the user name specified for the connection is used.
57 -a
59 --data-only
60 Dump only the data, not the schema (data definitions). Table data,
61 large objects, and sequence values are dumped.
62 This option is similar to, but for historical reasons not identical
64 to, specifying --section=data.
65 -b
67 --blobs
68 Include large objects in the dump. This is the default behavior
69 except when --schema, --table, or --schema-only is specified. The
70 -b switch is therefore only useful to add large objects to dumps
71 where a specific schema or table has been requested. Note that
72 blobs are considered data and therefore will be included when
73 --data-only is used, but not when --schema-only is.
74 -B
76 --no-blobs
77 Exclude large objects in the dump.
78 When both -b and -B are given, the behavior is to output large
80 objects, when data is being dumped, see the -b documentation.
81 -c
83 --clean
84 Output commands to clean (drop) database objects prior to
85 outputting the commands for creating them. (Unless --if-exists is
86 also specified, restore might generate some harmless error
87 messages, if any objects were not present in the destination
88 database.)
89 This option is ignored when emitting an archive (non-text) output
91 file. For the archive formats, you can specify the option when you
92 call pg_restore.
93 -C
95 --create
96 Begin the output with a command to create the database itself and
97 reconnect to the created database. (With a script of this form, it
98 doesn't matter which database in the destination installation you
99 connect to before running the script.) If --clean is also
100 specified, the script drops and recreates the target database
101 before reconnecting to it.
102 With --create, the output also includes the database's comment if
104 any, and any configuration variable settings that are specific to
105 this database, that is, any ALTER DATABASE ... SET ... and ALTER
106 ROLE ... IN DATABASE ... SET ... commands that mention this
107 database. Access privileges for the database itself are also
108 dumped, unless --no-acl is specified.
109 This option is ignored when emitting an archive (non-text) output
111 file. For the archive formats, you can specify the option when you
112 call pg_restore.
113 -e pattern
115 --extension=pattern
116 Dump only extensions matching pattern. When this option is not
117 specified, all non-system extensions in the target database will be
118 dumped. Multiple extensions can be selected by writing multiple -e
119 switches. The pattern parameter is interpreted as a pattern
120 according to the same rules used by psql's \d commands (see
121 Patterns), so multiple extensions can also be selected by writing
122 wildcard characters in the pattern. When using wildcards, be
123 careful to quote the pattern if needed to prevent the shell from
124 expanding the wildcards.
125 Any configuration relation registered by pg_extension_config_dump
127 is included in the dump if its extension is specified by
128 --extension.
129 Note
131 When -e is specified, pg_dump makes no attempt to dump any
132 other database objects that the selected extension(s) might
133 depend upon. Therefore, there is no guarantee that the results
134 of a specific-extension dump can be successfully restored by
135 themselves into a clean database.
136 -E encoding
138 --encoding=encoding
139 Create the dump in the specified character set encoding. By
140 default, the dump is created in the database encoding. (Another way
141 to get the same result is to set the PGCLIENTENCODING environment
142 variable to the desired dump encoding.) The supported encodings are
143 described in Section 24.3.1.
144 -f file
146 --file=file
147 Send output to the specified file. This parameter can be omitted
148 for file based output formats, in which case the standard output is
149 used. It must be given for the directory output format however,
150 where it specifies the target directory instead of a file. In this
151 case the directory is created by pg_dump and must not exist before.
152 -F format
154 --format=format
155 Selects the format of the output. format can be one of the
156 following:
157 p
159 plain
160 Output a plain-text SQL script file (the default).
161 c
163 custom
164 Output a custom-format archive suitable for input into
165 pg_restore. Together with the directory output format, this is
166 the most flexible output format in that it allows manual
167 selection and reordering of archived items during restore. This
168 format is also compressed by default.
169 d
171 directory
172 Output a directory-format archive suitable for input into
173 pg_restore. This will create a directory with one file for each
174 table and blob being dumped, plus a so-called Table of Contents
175 file describing the dumped objects in a machine-readable format
176 that pg_restore can read. A directory format archive can be
177 manipulated with standard Unix tools; for example, files in an
178 uncompressed archive can be compressed with the gzip tool. This
179 format is compressed by default and also supports parallel
180 dumps.
181 t
183 tar
184 Output a tar-format archive suitable for input into pg_restore.
185 The tar format is compatible with the directory format:
186 extracting a tar-format archive produces a valid
187 directory-format archive. However, the tar format does not
188 support compression. Also, when using tar format the relative
189 order of table data items cannot be changed during restore.
190 -j njobs
192 --jobs=njobs
193 Run the dump in parallel by dumping njobs tables simultaneously.
194 This option may reduce the time needed to perform the dump but it
195 also increases the load on the database server. You can only use
196 this option with the directory output format because this is the
197 only output format where multiple processes can write their data at
198 the same time.
199 pg_dump will open njobs + 1 connections to the database, so make
201 sure your max_connections setting is high enough to accommodate all
202 connections.
203 Requesting exclusive locks on database objects while running a
205 parallel dump could cause the dump to fail. The reason is that the
206 pg_dump leader process requests shared locks on the objects that
207 the worker processes are going to dump later in order to make sure
208 that nobody deletes them and makes them go away while the dump is
209 running. If another client then requests an exclusive lock on a
210 table, that lock will not be granted but will be queued waiting for
211 the shared lock of the leader process to be released. Consequently
212 any other access to the table will not be granted either and will
213 queue after the exclusive lock request. This includes the worker
214 process trying to dump the table. Without any precautions this
215 would be a classic deadlock situation. To detect this conflict, the
216 pg_dump worker process requests another shared lock using the
217 NOWAIT option. If the worker process is not granted this shared
218 lock, somebody else must have requested an exclusive lock in the
219 meantime and there is no way to continue with the dump, so pg_dump
220 has no choice but to abort the dump.
221 For a consistent backup, the database server needs to support
223 synchronized snapshots, a feature that was introduced in PostgreSQL
224 9.2 for primary servers and 10 for standbys. With this feature,
225 database clients can ensure they see the same data set even though
226 they use different connections. pg_dump -j uses multiple database
227 connections; it connects to the database once with the leader
228 process and once again for each worker job. Without the
229 synchronized snapshot feature, the different worker jobs wouldn't
230 be guaranteed to see the same data in each connection, which could
231 lead to an inconsistent backup.
232 If you want to run a parallel dump of a pre-9.2 server, you need to
234 make sure that the database content doesn't change from between the
235 time the leader connects to the database until the last worker job
236 has connected to the database. The easiest way to do this is to
237 halt any data modifying processes (DDL and DML) accessing the
238 database before starting the backup. You also need to specify the
239 --no-synchronized-snapshots parameter when running pg_dump -j
240 against a pre-9.2 PostgreSQL server.
241 -n pattern
243 --schema=pattern
244 Dump only schemas matching pattern; this selects both the schema
245 itself, and all its contained objects. When this option is not
246 specified, all non-system schemas in the target database will be
247 dumped. Multiple schemas can be selected by writing multiple -n
248 switches. The pattern parameter is interpreted as a pattern
249 according to the same rules used by psql's \d commands (see
250 Patterns below), so multiple schemas can also be selected by
251 writing wildcard characters in the pattern. When using wildcards,
252 be careful to quote the pattern if needed to prevent the shell from
253 expanding the wildcards; see Examples below.
254 Note
256 When -n is specified, pg_dump makes no attempt to dump any
257 other database objects that the selected schema(s) might depend
258 upon. Therefore, there is no guarantee that the results of a
259 specific-schema dump can be successfully restored by themselves
260 into a clean database.
261 Note
263 Non-schema objects such as blobs are not dumped when -n is
264 specified. You can add blobs back to the dump with the --blobs
265 switch.
266 -N pattern
268 --exclude-schema=pattern
269 Do not dump any schemas matching pattern. The pattern is
270 interpreted according to the same rules as for -n. -N can be given
271 more than once to exclude schemas matching any of several patterns.
272 When both -n and -N are given, the behavior is to dump just the
274 schemas that match at least one -n switch but no -N switches. If -N
275 appears without -n, then schemas matching -N are excluded from what
276 is otherwise a normal dump.
277 -O
279 --no-owner
280 Do not output commands to set ownership of objects to match the
281 original database. By default, pg_dump issues ALTER OWNER or SET
282 SESSION AUTHORIZATION statements to set ownership of created
283 database objects. These statements will fail when the script is run
284 unless it is started by a superuser (or the same user that owns all
285 of the objects in the script). To make a script that can be
286 restored by any user, but will give that user ownership of all the
287 objects, specify -O.
288 This option is ignored when emitting an archive (non-text) output
290 file. For the archive formats, you can specify the option when you
291 call pg_restore.
292 -R
294 --no-reconnect
295 This option is obsolete but still accepted for backwards
296 compatibility.
297 -s
299 --schema-only
300 Dump only the object definitions (schema), not data.
301 This option is the inverse of --data-only. It is similar to, but
303 for historical reasons not identical to, specifying
304 --section=pre-data --section=post-data.
305 (Do not confuse this with the --schema option, which uses the word
307 “schema” in a different meaning.)
308 To exclude table data for only a subset of tables in the database,
310 see --exclude-table-data.
311 -S username
313 --superuser=username
314 Specify the superuser user name to use when disabling triggers.
315 This is relevant only if --disable-triggers is used. (Usually, it's
316 better to leave this out, and instead start the resulting script as
317 superuser.)
318 -t pattern
320 --table=pattern
321 Dump only tables with names matching pattern. Multiple tables can
322 be selected by writing multiple -t switches. The pattern parameter
323 is interpreted as a pattern according to the same rules used by
324 psql's \d commands (see Patterns below), so multiple tables can
325 also be selected by writing wildcard characters in the pattern.
326 When using wildcards, be careful to quote the pattern if needed to
327 prevent the shell from expanding the wildcards; see Examples below.
328 As well as tables, this option can be used to dump the definition
330 of matching views, materialized views, foreign tables, and
331 sequences. It will not dump the contents of views or materialized
332 views, and the contents of foreign tables will only be dumped if
333 the corresponding foreign server is specified with
334 --include-foreign-data.
335 The -n and -N switches have no effect when -t is used, because
337 tables selected by -t will be dumped regardless of those switches,
338 and non-table objects will not be dumped.
339 Note
341 When -t is specified, pg_dump makes no attempt to dump any
342 other database objects that the selected table(s) might depend
343 upon. Therefore, there is no guarantee that the results of a
344 specific-table dump can be successfully restored by themselves
345 into a clean database.
346 -T pattern
348 --exclude-table=pattern
349 Do not dump any tables matching pattern. The pattern is interpreted
350 according to the same rules as for -t. -T can be given more than
351 once to exclude tables matching any of several patterns.
352 When both -t and -T are given, the behavior is to dump just the
354 tables that match at least one -t switch but no -T switches. If -T
355 appears without -t, then tables matching -T are excluded from what
356 is otherwise a normal dump.
357 -v
359 --verbose
360 Specifies verbose mode. This will cause pg_dump to output detailed
361 object comments and start/stop times to the dump file, and progress
362 messages to standard error. Repeating the option causes additional
363 debug-level messages to appear on standard error.
364 -V
366 --version
367 Print the pg_dump version and exit.
368 -x
370 --no-privileges
371 --no-acl
372 Prevent dumping of access privileges (grant/revoke commands).
373 -Z 0..9
375 --compress=0..9
376 Specify the compression level to use. Zero means no compression.
377 For the custom and directory archive formats, this specifies
378 compression of individual table-data segments, and the default is
379 to compress at a moderate level. For plain text output, setting a
380 nonzero compression level causes the entire output file to be
381 compressed, as though it had been fed through gzip; but the default
382 is not to compress. The tar archive format currently does not
383 support compression at all.
384 --binary-upgrade
386 This option is for use by in-place upgrade utilities. Its use for
387 other purposes is not recommended or supported. The behavior of the
388 option may change in future releases without notice.
389 --column-inserts
391 --attribute-inserts
392 Dump data as INSERT commands with explicit column names (INSERT
393 INTO table (column, ...) VALUES ...). This will make restoration
394 very slow; it is mainly useful for making dumps that can be loaded
395 into non-PostgreSQL databases. Any error during reloading will
396 cause only rows that are part of the problematic INSERT to be lost,
397 rather than the entire table contents.
398 --disable-dollar-quoting
400 This option disables the use of dollar quoting for function bodies,
401 and forces them to be quoted using SQL standard string syntax.
402 --disable-triggers
404 This option is relevant only when creating a data-only dump. It
405 instructs pg_dump to include commands to temporarily disable
406 triggers on the target tables while the data is reloaded. Use this
407 if you have referential integrity checks or other triggers on the
408 tables that you do not want to invoke during data reload.
409 Presently, the commands emitted for --disable-triggers must be done
411 as superuser. So, you should also specify a superuser name with -S,
412 or preferably be careful to start the resulting script as a
413 superuser.
414 This option is ignored when emitting an archive (non-text) output
416 file. For the archive formats, you can specify the option when you
417 call pg_restore.
418 --enable-row-security
420 This option is relevant only when dumping the contents of a table
421 which has row security. By default, pg_dump will set row_security
422 to off, to ensure that all data is dumped from the table. If the
423 user does not have sufficient privileges to bypass row security,
424 then an error is thrown. This parameter instructs pg_dump to set
425 row_security to on instead, allowing the user to dump the parts of
426 the contents of the table that they have access to.
427 Note that if you use this option currently, you probably also want
429 the dump be in INSERT format, as the COPY FROM during restore does
430 not support row security.
431 --exclude-table-data=pattern
433 Do not dump data for any tables matching pattern. The pattern is
434 interpreted according to the same rules as for -t.
435 --exclude-table-data can be given more than once to exclude tables
436 matching any of several patterns. This option is useful when you
437 need the definition of a particular table even though you do not
438 need the data in it.
439 To exclude data for all tables in the database, see --schema-only.
441 --extra-float-digits=ndigits
443 Use the specified value of extra_float_digits when dumping
444 floating-point data, instead of the maximum available precision.
445 Routine dumps made for backup purposes should not use this option.
446 --if-exists
448 Use conditional commands (i.e., add an IF EXISTS clause) when
449 cleaning database objects. This option is not valid unless --clean
450 is also specified.
451 --include-foreign-data=foreignserver
453 Dump the data for any foreign table with a foreign server matching
454 foreignserver pattern. Multiple foreign servers can be selected by
455 writing multiple --include-foreign-data switches. Also, the
456 foreignserver parameter is interpreted as a pattern according to
457 the same rules used by psql's \d commands (see Patterns below), so
458 multiple foreign servers can also be selected by writing wildcard
459 characters in the pattern. When using wildcards, be careful to
460 quote the pattern if needed to prevent the shell from expanding the
461 wildcards; see Examples below. The only exception is that an empty
462 pattern is disallowed.
463 Note
465 When --include-foreign-data is specified, pg_dump does not
466 check that the foreign table is writable. Therefore, there is
467 no guarantee that the results of a foreign table dump can be
468 successfully restored.
469 --inserts
471 Dump data as INSERT commands (rather than COPY). This will make
472 restoration very slow; it is mainly useful for making dumps that
473 can be loaded into non-PostgreSQL databases. Any error during
474 reloading will cause only rows that are part of the problematic
475 INSERT to be lost, rather than the entire table contents. Note that
476 the restore might fail altogether if you have rearranged column
477 order. The --column-inserts option is safe against column order
478 changes, though even slower.
479 --load-via-partition-root
481 When dumping data for a table partition, make the COPY or INSERT
482 statements target the root of the partitioning hierarchy that
483 contains it, rather than the partition itself. This causes the
484 appropriate partition to be re-determined for each row when the
485 data is loaded. This may be useful when reloading data on a server
486 where rows do not always fall into the same partitions as they did
487 on the original server. That could happen, for example, if the
488 partitioning column is of type text and the two systems have
489 different definitions of the collation used to sort the
490 partitioning column.
491 It is best not to use parallelism when restoring from an archive
493 made with this option, because pg_restore will not know exactly
494 which partition(s) a given archive data item will load data into.
495 This could result in inefficiency due to lock conflicts between
496 parallel jobs, or perhaps even reload failures due to foreign key
497 constraints being set up before all the relevant data is loaded.
498 --lock-wait-timeout=timeout
500 Do not wait forever to acquire shared table locks at the beginning
501 of the dump. Instead fail if unable to lock a table within the
502 specified timeout. The timeout may be specified in any of the
503 formats accepted by SET statement_timeout. (Allowed formats vary
504 depending on the server version you are dumping from, but an
505 integer number of milliseconds is accepted by all versions.)
506 --no-comments
508 Do not dump comments.
509 --no-publications
511 Do not dump publications.
512 --no-security-labels
514 Do not dump security labels.
515 --no-subscriptions
517 Do not dump subscriptions.
518 --no-sync
520 By default, pg_dump will wait for all files to be written safely to
521 disk. This option causes pg_dump to return without waiting, which
522 is faster, but means that a subsequent operating system crash can
523 leave the dump corrupt. Generally, this option is useful for
524 testing but should not be used when dumping data from production
525 installation.
526 --no-synchronized-snapshots
528 This option allows running pg_dump -j against a pre-9.2 server, see
529 the documentation of the -j parameter for more details.
530 --no-tablespaces
532 Do not output commands to select tablespaces. With this option, all
533 objects will be created in whichever tablespace is the default
534 during restore.
535 This option is ignored when emitting an archive (non-text) output
537 file. For the archive formats, you can specify the option when you
538 call pg_restore.
539 --no-toast-compression
541 Do not output commands to set TOAST compression methods. With this
542 option, all columns will be restored with the default compression
543 setting.
544 --no-unlogged-table-data
546 Do not dump the contents of unlogged tables. This option has no
547 effect on whether or not the table definitions (schema) are dumped;
548 it only suppresses dumping the table data. Data in unlogged tables
549 is always excluded when dumping from a standby server.
550 --on-conflict-do-nothing
552 Add ON CONFLICT DO NOTHING to INSERT commands. This option is not
553 valid unless --inserts, --column-inserts or --rows-per-insert is
554 also specified.
555 --quote-all-identifiers
557 Force quoting of all identifiers. This option is recommended when
558 dumping a database from a server whose PostgreSQL major version is
559 different from pg_dump's, or when the output is intended to be
560 loaded into a server of a different major version. By default,
561 pg_dump quotes only identifiers that are reserved words in its own
562 major version. This sometimes results in compatibility issues when
563 dealing with servers of other versions that may have slightly
564 different sets of reserved words. Using --quote-all-identifiers
565 prevents such issues, at the price of a harder-to-read dump script.
566 --rows-per-insert=nrows
568 Dump data as INSERT commands (rather than COPY). Controls the
569 maximum number of rows per INSERT command. The value specified must
570 be a number greater than zero. Any error during reloading will
571 cause only rows that are part of the problematic INSERT to be lost,
572 rather than the entire table contents.
573 --section=sectionname
575 Only dump the named section. The section name can be pre-data,
576 data, or post-data. This option can be specified more than once to
577 select multiple sections. The default is to dump all sections.
578 The data section contains actual table data, large-object contents,
580 and sequence values. Post-data items include definitions of
581 indexes, triggers, rules, and constraints other than validated
582 check constraints. Pre-data items include all other data definition
583 items.
584 --serializable-deferrable
586 Use a serializable transaction for the dump, to ensure that the
587 snapshot used is consistent with later database states; but do this
588 by waiting for a point in the transaction stream at which no
589 anomalies can be present, so that there isn't a risk of the dump
590 failing or causing other transactions to roll back with a
591 serialization_failure. See Chapter 13 for more information about
592 transaction isolation and concurrency control.
593 This option is not beneficial for a dump which is intended only for
595 disaster recovery. It could be useful for a dump used to load a
596 copy of the database for reporting or other read-only load sharing
597 while the original database continues to be updated. Without it the
598 dump may reflect a state which is not consistent with any serial
599 execution of the transactions eventually committed. For example, if
600 batch processing techniques are used, a batch may show as closed in
601 the dump without all of the items which are in the batch appearing.
602 This option will make no difference if there are no read-write
604 transactions active when pg_dump is started. If read-write
605 transactions are active, the start of the dump may be delayed for
606 an indeterminate length of time. Once running, performance with or
607 without the switch is the same.
608 --snapshot=snapshotname
610 Use the specified synchronized snapshot when making a dump of the
611 database (see Table 9.90 for more details).
612 This option is useful when needing to synchronize the dump with a
614 logical replication slot (see Chapter 49) or with a concurrent
615 session.
616 In the case of a parallel dump, the snapshot name defined by this
618 option is used rather than taking a new snapshot.
619 --strict-names
621 Require that each extension (-e/--extension), schema (-n/--schema)
622 and table (-t/--table) qualifier match at least one
623 extension/schema/table in the database to be dumped. Note that if
624 none of the extension/schema/table qualifiers find matches, pg_dump
625 will generate an error even without --strict-names.
626 This option has no effect on -N/--exclude-schema,
628 -T/--exclude-table, or --exclude-table-data. An exclude pattern
629 failing to match any objects is not considered an error.
630 --use-set-session-authorization
632 Output SQL-standard SET SESSION AUTHORIZATION commands instead of
633 ALTER OWNER commands to determine object ownership. This makes the
634 dump more standards-compatible, but depending on the history of the
635 objects in the dump, might not restore properly. Also, a dump using
636 SET SESSION AUTHORIZATION will certainly require superuser
637 privileges to restore correctly, whereas ALTER OWNER requires
638 lesser privileges.
639 -?
641 --help
642 Show help about pg_dump command line arguments, and exit.
643 The following command-line options control the database connection
645 parameters.
646 -d dbname
648 --dbname=dbname
649 Specifies the name of the database to connect to. This is
650 equivalent to specifying dbname as the first non-option argument on
651 the command line. The dbname can be a connection string. If so,
652 connection string parameters will override any conflicting command
653 line options.
654 -h host
656 --host=host
657 Specifies the host name of the machine on which the server is
658 running. If the value begins with a slash, it is used as the
659 directory for the Unix domain socket. The default is taken from the
660 PGHOST environment variable, if set, else a Unix domain socket
661 connection is attempted.
662 -p port
664 --port=port
665 Specifies the TCP port or local Unix domain socket file extension
666 on which the server is listening for connections. Defaults to the
667 PGPORT environment variable, if set, or a compiled-in default.
668 -U username
670 --username=username
671 User name to connect as.
672 -w
674 --no-password
675 Never issue a password prompt. If the server requires password
676 authentication and a password is not available by other means such
677 as a .pgpass file, the connection attempt will fail. This option
678 can be useful in batch jobs and scripts where no user is present to
679 enter a password.
680 -W
682 --password
683 Force pg_dump to prompt for a password before connecting to a
684 database.
685 This option is never essential, since pg_dump will automatically
687 prompt for a password if the server demands password
688 authentication. However, pg_dump will waste a connection attempt
689 finding out that the server wants a password. In some cases it is
690 worth typing -W to avoid the extra connection attempt.
691 --role=rolename
693 Specifies a role name to be used to create the dump. This option
694 causes pg_dump to issue a SET ROLE rolename command after
695 connecting to the database. It is useful when the authenticated
696 user (specified by -U) lacks privileges needed by pg_dump, but can
697 switch to a role with the required rights. Some installations have
698 a policy against logging in directly as a superuser, and use of
699 this option allows dumps to be made without violating the policy.
700
702 PGDATABASE
703 PGHOST
704 PGOPTIONS
705 PGPORT
706 PGUSER
707 Default connection parameters.
708 PG_COLOR
710 Specifies whether to use color in diagnostic messages. Possible
711 values are always, auto and never.
712 This utility, like most other PostgreSQL utilities, also uses the
714 environment variables supported by libpq (see Section 34.15).
715
717 pg_dump internally executes SELECT statements. If you have problems
718 running pg_dump, make sure you are able to select information from the
719 database using, for example, psql(1). Also, any default connection
720 settings and environment variables used by the libpq front-end library
721 will apply.
722 The database activity of pg_dump is normally collected by the
724 statistics collector. If this is undesirable, you can set parameter
725 track_counts to false via PGOPTIONS or the ALTER USER command.
726
728 If your database cluster has any local additions to the template1
729 database, be careful to restore the output of pg_dump into a truly
730 empty database; otherwise you are likely to get errors due to duplicate
731 definitions of the added objects. To make an empty database without any
732 local additions, copy from template0 not template1, for example:
733 CREATE DATABASE foo WITH TEMPLATE template0;
735 When a data-only dump is chosen and the option --disable-triggers is
737 used, pg_dump emits commands to disable triggers on user tables before
738 inserting the data, and then commands to re-enable them after the data
739 has been inserted. If the restore is stopped in the middle, the system
740 catalogs might be left in the wrong state.
741 The dump file produced by pg_dump does not contain the statistics used
743 by the optimizer to make query planning decisions. Therefore, it is
744 wise to run ANALYZE after restoring from a dump file to ensure optimal
745 performance; see Section 25.1.3 and Section 25.1.6 for more
746 information.
747 Because pg_dump is used to transfer data to newer versions of
749 PostgreSQL, the output of pg_dump can be expected to load into
750 PostgreSQL server versions newer than pg_dump's version. pg_dump can
751 also dump from PostgreSQL servers older than its own version.
752 (Currently, servers back to version 8.0 are supported.) However,
753 pg_dump cannot dump from PostgreSQL servers newer than its own major
754 version; it will refuse to even try, rather than risk making an invalid
755 dump. Also, it is not guaranteed that pg_dump's output can be loaded
756 into a server of an older major version — not even if the dump was
757 taken from a server of that version. Loading a dump file into an older
758 server may require manual editing of the dump file to remove syntax not
759 understood by the older server. Use of the --quote-all-identifiers
760 option is recommended in cross-version cases, as it can prevent
761 problems arising from varying reserved-word lists in different
762 PostgreSQL versions.
763 When dumping logical replication subscriptions, pg_dump will generate
765 CREATE SUBSCRIPTION commands that use the connect = false option, so
766 that restoring the subscription does not make remote connections for
767 creating a replication slot or for initial table copy. That way, the
768 dump can be restored without requiring network access to the remote
769 servers. It is then up to the user to reactivate the subscriptions in a
770 suitable way. If the involved hosts have changed, the connection
771 information might have to be changed. It might also be appropriate to
772 truncate the target tables before initiating a new full table copy.
773
775 To dump a database called mydb into an SQL-script file:
776 $ pg_dump mydb > db.sql
778 To reload such a script into a (freshly created) database named newdb:
780 $ psql -d newdb -f db.sql
782 To dump a database into a custom-format archive file:
784 $ pg_dump -Fc mydb > db.dump
786 To dump a database into a directory-format archive:
788 $ pg_dump -Fd mydb -f dumpdir
790 To dump a database into a directory-format archive in parallel with 5
792 worker jobs:
793 $ pg_dump -Fd mydb -j 5 -f dumpdir
795 To reload an archive file into a (freshly created) database named
797 newdb:
798 $ pg_restore -d newdb db.dump
800 To reload an archive file into the same database it was dumped from,
802 discarding the current contents of that database:
803 $ pg_restore -d postgres --clean --create db.dump
805 To dump a single table named mytab:
807 $ pg_dump -t mytab mydb > db.sql
809 To dump all tables whose names start with emp in the detroit schema,
811 except for the table named employee_log:
812 $ pg_dump -t 'detroit.emp*' -T detroit.employee_log mydb > db.sql
814 To dump all schemas whose names start with east or west and end in gsm,
816 excluding any schemas whose names contain the word test:
817 $ pg_dump -n 'east*gsm' -n 'west*gsm' -N '*test*' mydb > db.sql
819 The same, using regular expression notation to consolidate the
821 switches:
822 $ pg_dump -n '(east|west)*gsm' -N '*test*' mydb > db.sql
824 To dump all database objects except for tables whose names begin with
826 ts_:
827 $ pg_dump -T 'ts_*' mydb > db.sql
829 To specify an upper-case or mixed-case name in -t and related switches,
831 you need to double-quote the name; else it will be folded to lower case
832 (see Patterns below). But double quotes are special to the shell, so in
833 turn they must be quoted. Thus, to dump a single table with a
834 mixed-case name, you need something like
835 $ pg_dump -t "\"MixedCaseName\"" mydb > mytab.sql
837
839 pg_dumpall(1), pg_restore(1), psql(1)
840PostgreSQL 14.3 2022 PG_DUMP(1)