1PG_DUMP(1) PostgreSQL 12.6 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 encoding
115 --encoding=encoding
116 Create the dump in the specified character set encoding. By
117 default, the dump is created in the database encoding. (Another way
118 to get the same result is to set the PGCLIENTENCODING environment
119 variable to the desired dump encoding.)
120 -f file
122 --file=file
123 Send output to the specified file. This parameter can be omitted
124 for file based output formats, in which case the standard output is
125 used. It must be given for the directory output format however,
126 where it specifies the target directory instead of a file. In this
127 case the directory is created by pg_dump and must not exist before.
128 -F format
130 --format=format
131 Selects the format of the output. format can be one of the
132 following:
133 p
135 plain
136 Output a plain-text SQL script file (the default).
137 c
139 custom
140 Output a custom-format archive suitable for input into
141 pg_restore. Together with the directory output format, this is
142 the most flexible output format in that it allows manual
143 selection and reordering of archived items during restore. This
144 format is also compressed by default.
145 d
147 directory
148 Output a directory-format archive suitable for input into
149 pg_restore. This will create a directory with one file for each
150 table and blob being dumped, plus a so-called Table of Contents
151 file describing the dumped objects in a machine-readable format
152 that pg_restore can read. A directory format archive can be
153 manipulated with standard Unix tools; for example, files in an
154 uncompressed archive can be compressed with the gzip tool. This
155 format is compressed by default and also supports parallel
156 dumps.
157 t
159 tar
160 Output a tar-format archive suitable for input into pg_restore.
161 The tar format is compatible with the directory format:
162 extracting a tar-format archive produces a valid
163 directory-format archive. However, the tar format does not
164 support compression. Also, when using tar format the relative
165 order of table data items cannot be changed during restore.
166 -j njobs
168 --jobs=njobs
169 Run the dump in parallel by dumping njobs tables simultaneously.
170 This option reduces the time of the dump but it also increases the
171 load on the database server. You can only use this option with the
172 directory output format because this is the only output format
173 where multiple processes can write their data at the same time.
174 pg_dump will open njobs + 1 connections to the database, so make
176 sure your max_connections setting is high enough to accommodate all
177 connections.
178 Requesting exclusive locks on database objects while running a
180 parallel dump could cause the dump to fail. The reason is that the
181 pg_dump master process requests shared locks on the objects that
182 the worker processes are going to dump later in order to make sure
183 that nobody deletes them and makes them go away while the dump is
184 running. If another client then requests an exclusive lock on a
185 table, that lock will not be granted but will be queued waiting for
186 the shared lock of the master process to be released. Consequently
187 any other access to the table will not be granted either and will
188 queue after the exclusive lock request. This includes the worker
189 process trying to dump the table. Without any precautions this
190 would be a classic deadlock situation. To detect this conflict, the
191 pg_dump worker process requests another shared lock using the
192 NOWAIT option. If the worker process is not granted this shared
193 lock, somebody else must have requested an exclusive lock in the
194 meantime and there is no way to continue with the dump, so pg_dump
195 has no choice but to abort the dump.
196 For a consistent backup, the database server needs to support
198 synchronized snapshots, a feature that was introduced in PostgreSQL
199 9.2 for primary servers and 10 for standbys. With this feature,
200 database clients can ensure they see the same data set even though
201 they use different connections. pg_dump -j uses multiple database
202 connections; it connects to the database once with the master
203 process and once again for each worker job. Without the
204 synchronized snapshot feature, the different worker jobs wouldn't
205 be guaranteed to see the same data in each connection, which could
206 lead to an inconsistent backup.
207 If you want to run a parallel dump of a pre-9.2 server, you need to
209 make sure that the database content doesn't change from between the
210 time the master connects to the database until the last worker job
211 has connected to the database. The easiest way to do this is to
212 halt any data modifying processes (DDL and DML) accessing the
213 database before starting the backup. You also need to specify the
214 --no-synchronized-snapshots parameter when running pg_dump -j
215 against a pre-9.2 PostgreSQL server.
216 -n pattern
218 --schema=pattern
219 Dump only schemas matching pattern; this selects both the schema
220 itself, and all its contained objects. When this option is not
221 specified, all non-system schemas in the target database will be
222 dumped. Multiple schemas can be selected by writing multiple -n
223 switches. The pattern parameter is interpreted as a pattern
224 according to the same rules used by psql's \d commands (see
225 Patterns), so multiple schemas can also be selected by writing
226 wildcard characters in the pattern. When using wildcards, be
227 careful to quote the pattern if needed to prevent the shell from
228 expanding the wildcards; see EXAMPLES.
229 Note
231 When -n is specified, pg_dump makes no attempt to dump any
232 other database objects that the selected schema(s) might depend
233 upon. Therefore, there is no guarantee that the results of a
234 specific-schema dump can be successfully restored by themselves
235 into a clean database.
236 Note
238 Non-schema objects such as blobs are not dumped when -n is
239 specified. You can add blobs back to the dump with the --blobs
240 switch.
241 -N pattern
243 --exclude-schema=pattern
244 Do not dump any schemas matching pattern. The pattern is
245 interpreted according to the same rules as for -n. -N can be given
246 more than once to exclude schemas matching any of several patterns.
247 When both -n and -N are given, the behavior is to dump just the
249 schemas that match at least one -n switch but no -N switches. If -N
250 appears without -n, then schemas matching -N are excluded from what
251 is otherwise a normal dump.
252 -O
254 --no-owner
255 Do not output commands to set ownership of objects to match the
256 original database. By default, pg_dump issues ALTER OWNER or SET
257 SESSION AUTHORIZATION statements to set ownership of created
258 database objects. These statements will fail when the script is run
259 unless it is started by a superuser (or the same user that owns all
260 of the objects in the script). To make a script that can be
261 restored by any user, but will give that user ownership of all the
262 objects, specify -O.
263 This option is ignored when emitting an archive (non-text) output
265 file. For the archive formats, you can specify the option when you
266 call pg_restore.
267 -R
269 --no-reconnect
270 This option is obsolete but still accepted for backwards
271 compatibility.
272 -s
274 --schema-only
275 Dump only the object definitions (schema), not data.
276 This option is the inverse of --data-only. It is similar to, but
278 for historical reasons not identical to, specifying
279 --section=pre-data --section=post-data.
280 (Do not confuse this with the --schema option, which uses the word
282 “schema” in a different meaning.)
283 To exclude table data for only a subset of tables in the database,
285 see --exclude-table-data.
286 -S username
288 --superuser=username
289 Specify the superuser user name to use when disabling triggers.
290 This is relevant only if --disable-triggers is used. (Usually, it's
291 better to leave this out, and instead start the resulting script as
292 superuser.)
293 -t pattern
295 --table=pattern
296 Dump only tables with names matching pattern. For this purpose,
297 “table” includes views, materialized views, sequences, and foreign
298 tables. Multiple tables can be selected by writing multiple -t
299 switches. The pattern parameter is interpreted as a pattern
300 according to the same rules used by psql's \d commands (see
301 Patterns), so multiple tables can also be selected by writing
302 wildcard characters in the pattern. When using wildcards, be
303 careful to quote the pattern if needed to prevent the shell from
304 expanding the wildcards; see EXAMPLES.
305 The -n and -N switches have no effect when -t is used, because
307 tables selected by -t will be dumped regardless of those switches,
308 and non-table objects will not be dumped.
309 Note
311 When -t is specified, pg_dump makes no attempt to dump any
312 other database objects that the selected table(s) might depend
313 upon. Therefore, there is no guarantee that the results of a
314 specific-table dump can be successfully restored by themselves
315 into a clean database.
316 Note
318 The behavior of the -t switch is not entirely upward compatible
319 with pre-8.2 PostgreSQL versions. Formerly, writing -t tab
320 would dump all tables named tab, but now it just dumps
321 whichever one is visible in your default search path. To get
322 the old behavior you can write -t '*.tab'. Also, you must write
323 something like -t sch.tab to select a table in a particular
324 schema, rather than the old locution of -n sch -t tab.
325 -T pattern
327 --exclude-table=pattern
328 Do not dump any tables matching pattern. The pattern is interpreted
329 according to the same rules as for -t. -T can be given more than
330 once to exclude tables matching any of several patterns.
331 When both -t and -T are given, the behavior is to dump just the
333 tables that match at least one -t switch but no -T switches. If -T
334 appears without -t, then tables matching -T are excluded from what
335 is otherwise a normal dump.
336 -v
338 --verbose
339 Specifies verbose mode. This will cause pg_dump to output detailed
340 object comments and start/stop times to the dump file, and progress
341 messages to standard error.
342 -V
344 --version
345 Print the pg_dump version and exit.
346 -x
348 --no-privileges
349 --no-acl
350 Prevent dumping of access privileges (grant/revoke commands).
351 -Z 0..9
353 --compress=0..9
354 Specify the compression level to use. Zero means no compression.
355 For the custom and directory archive formats, this specifies
356 compression of individual table-data segments, and the default is
357 to compress at a moderate level. For plain text output, setting a
358 nonzero compression level causes the entire output file to be
359 compressed, as though it had been fed through gzip; but the default
360 is not to compress. The tar archive format currently does not
361 support compression at all.
362 --binary-upgrade
364 This option is for use by in-place upgrade utilities. Its use for
365 other purposes is not recommended or supported. The behavior of the
366 option may change in future releases without notice.
367 --column-inserts
369 --attribute-inserts
370 Dump data as INSERT commands with explicit column names (INSERT
371 INTO table (column, ...) VALUES ...). This will make restoration
372 very slow; it is mainly useful for making dumps that can be loaded
373 into non-PostgreSQL databases. Any error during reloading will
374 cause only rows that are part of the problematic INSERT to be lost,
375 rather than the entire table contents.
376 --disable-dollar-quoting
378 This option disables the use of dollar quoting for function bodies,
379 and forces them to be quoted using SQL standard string syntax.
380 --disable-triggers
382 This option is relevant only when creating a data-only dump. It
383 instructs pg_dump to include commands to temporarily disable
384 triggers on the target tables while the data is reloaded. Use this
385 if you have referential integrity checks or other triggers on the
386 tables that you do not want to invoke during data reload.
387 Presently, the commands emitted for --disable-triggers must be done
389 as superuser. So, you should also specify a superuser name with -S,
390 or preferably be careful to start the resulting script as a
391 superuser.
392 This option is ignored when emitting an archive (non-text) output
394 file. For the archive formats, you can specify the option when you
395 call pg_restore.
396 --enable-row-security
398 This option is relevant only when dumping the contents of a table
399 which has row security. By default, pg_dump will set row_security
400 to off, to ensure that all data is dumped from the table. If the
401 user does not have sufficient privileges to bypass row security,
402 then an error is thrown. This parameter instructs pg_dump to set
403 row_security to on instead, allowing the user to dump the parts of
404 the contents of the table that they have access to.
405 Note that if you use this option currently, you probably also want
407 the dump be in INSERT format, as the COPY FROM during restore does
408 not support row security.
409 --exclude-table-data=pattern
411 Do not dump data for any tables matching pattern. The pattern is
412 interpreted according to the same rules as for -t.
413 --exclude-table-data can be given more than once to exclude tables
414 matching any of several patterns. This option is useful when you
415 need the definition of a particular table even though you do not
416 need the data in it.
417 To exclude data for all tables in the database, see --schema-only.
419 --extra-float-digits=ndigits
421 Use the specified value of extra_float_digits when dumping
422 floating-point data, instead of the maximum available precision.
423 Routine dumps made for backup purposes should not use this option.
424 --if-exists
426 Use conditional commands (i.e., add an IF EXISTS clause) when
427 cleaning database objects. This option is not valid unless --clean
428 is also specified.
429 --inserts
431 Dump data as INSERT commands (rather than COPY). This will make
432 restoration very slow; it is mainly useful for making dumps that
433 can be loaded into non-PostgreSQL databases. Any error during
434 reloading will cause only rows that are part of the problematic
435 INSERT to be lost, rather than the entire table contents. Note that
436 the restore might fail altogether if you have rearranged column
437 order. The --column-inserts option is safe against column order
438 changes, though even slower.
439 --load-via-partition-root
441 When dumping data for a table partition, make the COPY or INSERT
442 statements target the root of the partitioning hierarchy that
443 contains it, rather than the partition itself. This causes the
444 appropriate partition to be re-determined for each row when the
445 data is loaded. This may be useful when reloading data on a server
446 where rows do not always fall into the same partitions as they did
447 on the original server. That could happen, for example, if the
448 partitioning column is of type text and the two systems have
449 different definitions of the collation used to sort the
450 partitioning column.
451 It is best not to use parallelism when restoring from an archive
453 made with this option, because pg_restore will not know exactly
454 which partition(s) a given archive data item will load data into.
455 This could result in inefficiency due to lock conflicts between
456 parallel jobs, or perhaps even reload failures due to foreign key
457 constraints being set up before all the relevant data is loaded.
458 --lock-wait-timeout=timeout
460 Do not wait forever to acquire shared table locks at the beginning
461 of the dump. Instead fail if unable to lock a table within the
462 specified timeout. The timeout may be specified in any of the
463 formats accepted by SET statement_timeout. (Allowed formats vary
464 depending on the server version you are dumping from, but an
465 integer number of milliseconds is accepted by all versions.)
466 --no-comments
468 Do not dump comments.
469 --no-publications
471 Do not dump publications.
472 --no-security-labels
474 Do not dump security labels.
475 --no-subscriptions
477 Do not dump subscriptions.
478 --no-sync
480 By default, pg_dump will wait for all files to be written safely to
481 disk. This option causes pg_dump to return without waiting, which
482 is faster, but means that a subsequent operating system crash can
483 leave the dump corrupt. Generally, this option is useful for
484 testing but should not be used when dumping data from production
485 installation.
486 --no-synchronized-snapshots
488 This option allows running pg_dump -j against a pre-9.2 server, see
489 the documentation of the -j parameter for more details.
490 --no-tablespaces
492 Do not output commands to select tablespaces. With this option, all
493 objects will be created in whichever tablespace is the default
494 during restore.
495 This option is ignored when emitting an archive (non-text) output
497 file. For the archive formats, you can specify the option when you
498 call pg_restore.
499 --no-unlogged-table-data
501 Do not dump the contents of unlogged tables. This option has no
502 effect on whether or not the table definitions (schema) are dumped;
503 it only suppresses dumping the table data. Data in unlogged tables
504 is always excluded when dumping from a standby server.
505 --on-conflict-do-nothing
507 Add ON CONFLICT DO NOTHING to INSERT commands. This option is not
508 valid unless --inserts, --column-inserts or --rows-per-insert is
509 also specified.
510 --quote-all-identifiers
512 Force quoting of all identifiers. This option is recommended when
513 dumping a database from a server whose PostgreSQL major version is
514 different from pg_dump's, or when the output is intended to be
515 loaded into a server of a different major version. By default,
516 pg_dump quotes only identifiers that are reserved words in its own
517 major version. This sometimes results in compatibility issues when
518 dealing with servers of other versions that may have slightly
519 different sets of reserved words. Using --quote-all-identifiers
520 prevents such issues, at the price of a harder-to-read dump script.
521 --rows-per-insert=nrows
523 Dump data as INSERT commands (rather than COPY). Controls the
524 maximum number of rows per INSERT command. The value specified must
525 be a number greater than zero. Any error during reloading will
526 cause only rows that are part of the problematic INSERT to be lost,
527 rather than the entire table contents.
528 --section=sectionname
530 Only dump the named section. The section name can be pre-data,
531 data, or post-data. This option can be specified more than once to
532 select multiple sections. The default is to dump all sections.
533 The data section contains actual table data, large-object contents,
535 and sequence values. Post-data items include definitions of
536 indexes, triggers, rules, and constraints other than validated
537 check constraints. Pre-data items include all other data definition
538 items.
539 --serializable-deferrable
541 Use a serializable transaction for the dump, to ensure that the
542 snapshot used is consistent with later database states; but do this
543 by waiting for a point in the transaction stream at which no
544 anomalies can be present, so that there isn't a risk of the dump
545 failing or causing other transactions to roll back with a
546 serialization_failure. See Chapter 13 for more information about
547 transaction isolation and concurrency control.
548 This option is not beneficial for a dump which is intended only for
550 disaster recovery. It could be useful for a dump used to load a
551 copy of the database for reporting or other read-only load sharing
552 while the original database continues to be updated. Without it the
553 dump may reflect a state which is not consistent with any serial
554 execution of the transactions eventually committed. For example, if
555 batch processing techniques are used, a batch may show as closed in
556 the dump without all of the items which are in the batch appearing.
557 This option will make no difference if there are no read-write
559 transactions active when pg_dump is started. If read-write
560 transactions are active, the start of the dump may be delayed for
561 an indeterminate length of time. Once running, performance with or
562 without the switch is the same.
563 --snapshot=snapshotname
565 Use the specified synchronized snapshot when making a dump of the
566 database (see Table 9.87 for more details).
567 This option is useful when needing to synchronize the dump with a
569 logical replication slot (see Chapter 48) or with a concurrent
570 session.
571 In the case of a parallel dump, the snapshot name defined by this
573 option is used rather than taking a new snapshot.
574 --strict-names
576 Require that each schema (-n/--schema) and table (-t/--table)
577 qualifier match at least one schema/table in the database to be
578 dumped. Note that if none of the schema/table qualifiers find
579 matches, pg_dump will generate an error even without
580 --strict-names.
581 This option has no effect on -N/--exclude-schema,
583 -T/--exclude-table, or --exclude-table-data. An exclude pattern
584 failing to match any objects is not considered an error.
585 --use-set-session-authorization
587 Output SQL-standard SET SESSION AUTHORIZATION commands instead of
588 ALTER OWNER commands to determine object ownership. This makes the
589 dump more standards-compatible, but depending on the history of the
590 objects in the dump, might not restore properly. Also, a dump using
591 SET SESSION AUTHORIZATION will certainly require superuser
592 privileges to restore correctly, whereas ALTER OWNER requires
593 lesser privileges.
594 -?
596 --help
597 Show help about pg_dump command line arguments, and exit.
598 The following command-line options control the database connection
600 parameters.
601 -d dbname
603 --dbname=dbname
604 Specifies the name of the database to connect to. This is
605 equivalent to specifying dbname as the first non-option argument on
606 the command line. The dbname can be a connection string. If so,
607 connection string parameters will override any conflicting command
608 line options.
609 -h host
611 --host=host
612 Specifies the host name of the machine on which the server is
613 running. If the value begins with a slash, it is used as the
614 directory for the Unix domain socket. The default is taken from the
615 PGHOST environment variable, if set, else a Unix domain socket
616 connection is attempted.
617 -p port
619 --port=port
620 Specifies the TCP port or local Unix domain socket file extension
621 on which the server is listening for connections. Defaults to the
622 PGPORT environment variable, if set, or a compiled-in default.
623 -U username
625 --username=username
626 User name to connect as.
627 -w
629 --no-password
630 Never issue a password prompt. If the server requires password
631 authentication and a password is not available by other means such
632 as a .pgpass file, the connection attempt will fail. This option
633 can be useful in batch jobs and scripts where no user is present to
634 enter a password.
635 -W
637 --password
638 Force pg_dump to prompt for a password before connecting to a
639 database.
640 This option is never essential, since pg_dump will automatically
642 prompt for a password if the server demands password
643 authentication. However, pg_dump will waste a connection attempt
644 finding out that the server wants a password. In some cases it is
645 worth typing -W to avoid the extra connection attempt.
646 --role=rolename
648 Specifies a role name to be used to create the dump. This option
649 causes pg_dump to issue a SET ROLE rolename command after
650 connecting to the database. It is useful when the authenticated
651 user (specified by -U) lacks privileges needed by pg_dump, but can
652 switch to a role with the required rights. Some installations have
653 a policy against logging in directly as a superuser, and use of
654 this option allows dumps to be made without violating the policy.
655
657 PGDATABASE
658 PGHOST
659 PGOPTIONS
660 PGPORT
661 PGUSER
662 Default connection parameters.
663 PG_COLOR
665 Specifies whether to use color in diagnostic messages. Possible
666 values are always, auto and never.
667 This utility, like most other PostgreSQL utilities, also uses the
669 environment variables supported by libpq (see Section 33.14).
670
672 pg_dump internally executes SELECT statements. If you have problems
673 running pg_dump, make sure you are able to select information from the
674 database using, for example, psql(1). Also, any default connection
675 settings and environment variables used by the libpq front-end library
676 will apply.
677 The database activity of pg_dump is normally collected by the
679 statistics collector. If this is undesirable, you can set parameter
680 track_counts to false via PGOPTIONS or the ALTER USER command.
681
683 If your database cluster has any local additions to the template1
684 database, be careful to restore the output of pg_dump into a truly
685 empty database; otherwise you are likely to get errors due to duplicate
686 definitions of the added objects. To make an empty database without any
687 local additions, copy from template0 not template1, for example:
688 CREATE DATABASE foo WITH TEMPLATE template0;
690 When a data-only dump is chosen and the option --disable-triggers is
692 used, pg_dump emits commands to disable triggers on user tables before
693 inserting the data, and then commands to re-enable them after the data
694 has been inserted. If the restore is stopped in the middle, the system
695 catalogs might be left in the wrong state.
696 The dump file produced by pg_dump does not contain the statistics used
698 by the optimizer to make query planning decisions. Therefore, it is
699 wise to run ANALYZE after restoring from a dump file to ensure optimal
700 performance; see Section 24.1.3 and Section 24.1.6 for more
701 information.
702 Because pg_dump is used to transfer data to newer versions of
704 PostgreSQL, the output of pg_dump can be expected to load into
705 PostgreSQL server versions newer than pg_dump's version. pg_dump can
706 also dump from PostgreSQL servers older than its own version.
707 (Currently, servers back to version 8.0 are supported.) However,
708 pg_dump cannot dump from PostgreSQL servers newer than its own major
709 version; it will refuse to even try, rather than risk making an invalid
710 dump. Also, it is not guaranteed that pg_dump's output can be loaded
711 into a server of an older major version — not even if the dump was
712 taken from a server of that version. Loading a dump file into an older
713 server may require manual editing of the dump file to remove syntax not
714 understood by the older server. Use of the --quote-all-identifiers
715 option is recommended in cross-version cases, as it can prevent
716 problems arising from varying reserved-word lists in different
717 PostgreSQL versions.
718 When dumping logical replication subscriptions, pg_dump will generate
720 CREATE SUBSCRIPTION commands that use the connect = false option, so
721 that restoring the subscription does not make remote connections for
722 creating a replication slot or for initial table copy. That way, the
723 dump can be restored without requiring network access to the remote
724 servers. It is then up to the user to reactivate the subscriptions in a
725 suitable way. If the involved hosts have changed, the connection
726 information might have to be changed. It might also be appropriate to
727 truncate the target tables before initiating a new full table copy.
728
730 To dump a database called mydb into a SQL-script file:
731 $ pg_dump mydb > db.sql
733 To reload such a script into a (freshly created) database named newdb:
735 $ psql -d newdb -f db.sql
737 To dump a database into a custom-format archive file:
739 $ pg_dump -Fc mydb > db.dump
741 To dump a database into a directory-format archive:
743 $ pg_dump -Fd mydb -f dumpdir
745 To dump a database into a directory-format archive in parallel with 5
747 worker jobs:
748 $ pg_dump -Fd mydb -j 5 -f dumpdir
750 To reload an archive file into a (freshly created) database named
752 newdb:
753 $ pg_restore -d newdb db.dump
755 To reload an archive file into the same database it was dumped from,
757 discarding the current contents of that database:
758 $ pg_restore -d postgres --clean --create db.dump
760 To dump a single table named mytab:
762 $ pg_dump -t mytab mydb > db.sql
764 To dump all tables whose names start with emp in the detroit schema,
766 except for the table named employee_log:
767 $ pg_dump -t 'detroit.emp*' -T detroit.employee_log mydb > db.sql
769 To dump all schemas whose names start with east or west and end in gsm,
771 excluding any schemas whose names contain the word test:
772 $ pg_dump -n 'east*gsm' -n 'west*gsm' -N '*test*' mydb > db.sql
774 The same, using regular expression notation to consolidate the
776 switches:
777 $ pg_dump -n '(east|west)*gsm' -N '*test*' mydb > db.sql
779 To dump all database objects except for tables whose names begin with
781 ts_:
782 $ pg_dump -T 'ts_*' mydb > db.sql
784 To specify an upper-case or mixed-case name in -t and related switches,
786 you need to double-quote the name; else it will be folded to lower case
787 (see Patterns). But double quotes are special to the shell, so in turn
788 they must be quoted. Thus, to dump a single table with a mixed-case
789 name, you need something like
790 $ pg_dump -t "\"MixedCaseName\"" mydb > mytab.sql
792
794 pg_dumpall(1), pg_restore(1), psql(1)
795PostgreSQL 12.6 2021 PG_DUMP(1)