1PG_DUMP(1) PostgreSQL 11.3 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 only meaningful for the plain-text format. For the
91 archive formats, you can specify the option when you call
92 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 only meaningful for the plain-text format. For the
111 archive formats, you can specify the option when you call
112 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 schema
218 --schema=schema
219 Dump only schemas matching schema; 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. Also, the schema 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 schema
243 --exclude-schema=schema
244 Do not dump any schemas matching the schema 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 --oids
255 Dump object identifiers (OIDs) as part of the data for every table.
256 Use this option if your application references the OID columns in
257 some way (e.g., in a foreign key constraint). Otherwise, this
258 option should not be used.
259 -O
261 --no-owner
262 Do not output commands to set ownership of objects to match the
263 original database. By default, pg_dump issues ALTER OWNER or SET
264 SESSION AUTHORIZATION statements to set ownership of created
265 database objects. These statements will fail when the script is run
266 unless it is started by a superuser (or the same user that owns all
267 of the objects in the script). To make a script that can be
268 restored by any user, but will give that user ownership of all the
269 objects, specify -O.
270 This option is only meaningful for the plain-text format. For the
272 archive formats, you can specify the option when you call
273 pg_restore.
274 -R
276 --no-reconnect
277 This option is obsolete but still accepted for backwards
278 compatibility.
279 -s
281 --schema-only
282 Dump only the object definitions (schema), not data.
283 This option is the inverse of --data-only. It is similar to, but
285 for historical reasons not identical to, specifying
286 --section=pre-data --section=post-data.
287 (Do not confuse this with the --schema option, which uses the word
289 “schema” in a different meaning.)
290 To exclude table data for only a subset of tables in the database,
292 see --exclude-table-data.
293 -S username
295 --superuser=username
296 Specify the superuser user name to use when disabling triggers.
297 This is relevant only if --disable-triggers is used. (Usually, it's
298 better to leave this out, and instead start the resulting script as
299 superuser.)
300 -t table
302 --table=table
303 Dump only tables with names matching table. For this purpose,
304 “table” includes views, materialized views, sequences, and foreign
305 tables. Multiple tables can be selected by writing multiple -t
306 switches. Also, the table parameter is interpreted as a pattern
307 according to the same rules used by psql's \d commands (see
308 Patterns), so multiple tables can also be selected by writing
309 wildcard characters in the pattern. When using wildcards, be
310 careful to quote the pattern if needed to prevent the shell from
311 expanding the wildcards; see EXAMPLES.
312 The -n and -N switches have no effect when -t is used, because
314 tables selected by -t will be dumped regardless of those switches,
315 and non-table objects will not be dumped.
316 Note
318 When -t is specified, pg_dump makes no attempt to dump any
319 other database objects that the selected table(s) might depend
320 upon. Therefore, there is no guarantee that the results of a
321 specific-table dump can be successfully restored by themselves
322 into a clean database.
323 Note
325 The behavior of the -t switch is not entirely upward compatible
326 with pre-8.2 PostgreSQL versions. Formerly, writing -t tab
327 would dump all tables named tab, but now it just dumps
328 whichever one is visible in your default search path. To get
329 the old behavior you can write -t '*.tab'. Also, you must write
330 something like -t sch.tab to select a table in a particular
331 schema, rather than the old locution of -n sch -t tab.
332 -T table
334 --exclude-table=table
335 Do not dump any tables matching the table pattern. The pattern is
336 interpreted according to the same rules as for -t. -T can be given
337 more than once to exclude tables matching any of several patterns.
338 When both -t and -T are given, the behavior is to dump just the
340 tables that match at least one -t switch but no -T switches. If -T
341 appears without -t, then tables matching -T are excluded from what
342 is otherwise a normal dump.
343 -v
345 --verbose
346 Specifies verbose mode. This will cause pg_dump to output detailed
347 object comments and start/stop times to the dump file, and progress
348 messages to standard error.
349 -V
351 --version
352 Print the pg_dump version and exit.
353 -x
355 --no-privileges
356 --no-acl
357 Prevent dumping of access privileges (grant/revoke commands).
358 -Z 0..9
360 --compress=0..9
361 Specify the compression level to use. Zero means no compression.
362 For the custom archive format, this specifies compression of
363 individual table-data segments, and the default is to compress at a
364 moderate level. For plain text output, setting a nonzero
365 compression level causes the entire output file to be compressed,
366 as though it had been fed through gzip; but the default is not to
367 compress. The tar archive format currently does not support
368 compression at all.
369 --binary-upgrade
371 This option is for use by in-place upgrade utilities. Its use for
372 other purposes is not recommended or supported. The behavior of the
373 option may change in future releases without notice.
374 --column-inserts
376 --attribute-inserts
377 Dump data as INSERT commands with explicit column names (INSERT
378 INTO table (column, ...) VALUES ...). This will make restoration
379 very slow; it is mainly useful for making dumps that can be loaded
380 into non-PostgreSQL databases. However, since this option generates
381 a separate command for each row, an error in reloading a row causes
382 only that row to be lost rather than the entire table contents.
383 --disable-dollar-quoting
385 This option disables the use of dollar quoting for function bodies,
386 and forces them to be quoted using SQL standard string syntax.
387 --disable-triggers
389 This option is relevant only when creating a data-only dump. It
390 instructs pg_dump to include commands to temporarily disable
391 triggers on the target tables while the data is reloaded. Use this
392 if you have referential integrity checks or other triggers on the
393 tables that you do not want to invoke during data reload.
394 Presently, the commands emitted for --disable-triggers must be done
396 as superuser. So, you should also specify a superuser name with -S,
397 or preferably be careful to start the resulting script as a
398 superuser.
399 This option is only meaningful for the plain-text format. For the
401 archive formats, you can specify the option when you call
402 pg_restore.
403 --enable-row-security
405 This option is relevant only when dumping the contents of a table
406 which has row security. By default, pg_dump will set row_security
407 to off, to ensure that all data is dumped from the table. If the
408 user does not have sufficient privileges to bypass row security,
409 then an error is thrown. This parameter instructs pg_dump to set
410 row_security to on instead, allowing the user to dump the parts of
411 the contents of the table that they have access to.
412 Note that if you use this option currently, you probably also want
414 the dump be in INSERT format, as the COPY FROM during restore does
415 not support row security.
416 --exclude-table-data=table
418 Do not dump data for any tables matching the table pattern. The
419 pattern is interpreted according to the same rules as for -t.
420 --exclude-table-data can be given more than once to exclude tables
421 matching any of several patterns. This option is useful when you
422 need the definition of a particular table even though you do not
423 need the data in it.
424 To exclude data for all tables in the database, see --schema-only.
426 --if-exists
428 Use conditional commands (i.e. add an IF EXISTS clause) when
429 cleaning database objects. This option is not valid unless --clean
430 is also specified.
431 --inserts
433 Dump data as INSERT commands (rather than COPY). This will make
434 restoration very slow; it is mainly useful for making dumps that
435 can be loaded into non-PostgreSQL databases. However, since this
436 option generates a separate command for each row, an error in
437 reloading a row causes only that row to be lost rather than the
438 entire table contents. Note that the restore might fail altogether
439 if you have rearranged column order. The --column-inserts option is
440 safe against column order changes, though even slower.
441 --load-via-partition-root
443 When dumping data for a table partition, make the COPY or INSERT
444 statements target the root of the partitioning hierarchy that
445 contains it, rather than the partition itself. This causes the
446 appropriate partition to be re-determined for each row when the
447 data is loaded. This may be useful when reloading data on a server
448 where rows do not always fall into the same partitions as they did
449 on the original server. That could happen, for example, if the
450 partitioning column is of type text and the two systems have
451 different definitions of the collation used to sort the
452 partitioning column.
453 It is best not to use parallelism when restoring from an archive
455 made with this option, because pg_restore will not know exactly
456 which partition(s) a given archive data item will load data into.
457 This could result in inefficiency due to lock conflicts between
458 parallel jobs, or perhaps even reload failures due to foreign key
459 constraints being set up before all the relevant data is loaded.
460 --lock-wait-timeout=timeout
462 Do not wait forever to acquire shared table locks at the beginning
463 of the dump. Instead fail if unable to lock a table within the
464 specified timeout. The timeout may be specified in any of the
465 formats accepted by SET statement_timeout. (Allowed formats vary
466 depending on the server version you are dumping from, but an
467 integer number of milliseconds is accepted by all versions.)
468 --no-comments
470 Do not dump comments.
471 --no-publications
473 Do not dump publications.
474 --no-security-labels
476 Do not dump security labels.
477 --no-subscriptions
479 Do not dump subscriptions.
480 --no-sync
482 By default, pg_dump will wait for all files to be written safely to
483 disk. This option causes pg_dump to return without waiting, which
484 is faster, but means that a subsequent operating system crash can
485 leave the dump corrupt. Generally, this option is useful for
486 testing but should not be used when dumping data from production
487 installation.
488 --no-synchronized-snapshots
490 This option allows running pg_dump -j against a pre-9.2 server, see
491 the documentation of the -j parameter for more details.
492 --no-tablespaces
494 Do not output commands to select tablespaces. With this option, all
495 objects will be created in whichever tablespace is the default
496 during restore.
497 This option is only meaningful for the plain-text format. For the
499 archive formats, you can specify the option when you call
500 pg_restore.
501 --no-unlogged-table-data
503 Do not dump the contents of unlogged tables. This option has no
504 effect on whether or not the table definitions (schema) are dumped;
505 it only suppresses dumping the table data. Data in unlogged tables
506 is always excluded when dumping from a standby server.
507 --quote-all-identifiers
509 Force quoting of all identifiers. This option is recommended when
510 dumping a database from a server whose PostgreSQL major version is
511 different from pg_dump's, or when the output is intended to be
512 loaded into a server of a different major version. By default,
513 pg_dump quotes only identifiers that are reserved words in its own
514 major version. This sometimes results in compatibility issues when
515 dealing with servers of other versions that may have slightly
516 different sets of reserved words. Using --quote-all-identifiers
517 prevents such issues, at the price of a harder-to-read dump script.
518 --section=sectionname
520 Only dump the named section. The section name can be pre-data,
521 data, or post-data. This option can be specified more than once to
522 select multiple sections. The default is to dump all sections.
523 The data section contains actual table data, large-object contents,
525 and sequence values. Post-data items include definitions of
526 indexes, triggers, rules, and constraints other than validated
527 check constraints. Pre-data items include all other data definition
528 items.
529 --serializable-deferrable
531 Use a serializable transaction for the dump, to ensure that the
532 snapshot used is consistent with later database states; but do this
533 by waiting for a point in the transaction stream at which no
534 anomalies can be present, so that there isn't a risk of the dump
535 failing or causing other transactions to roll back with a
536 serialization_failure. See Chapter 13 for more information about
537 transaction isolation and concurrency control.
538 This option is not beneficial for a dump which is intended only for
540 disaster recovery. It could be useful for a dump used to load a
541 copy of the database for reporting or other read-only load sharing
542 while the original database continues to be updated. Without it the
543 dump may reflect a state which is not consistent with any serial
544 execution of the transactions eventually committed. For example, if
545 batch processing techniques are used, a batch may show as closed in
546 the dump without all of the items which are in the batch appearing.
547 This option will make no difference if there are no read-write
549 transactions active when pg_dump is started. If read-write
550 transactions are active, the start of the dump may be delayed for
551 an indeterminate length of time. Once running, performance with or
552 without the switch is the same.
553 --snapshot=snapshotname
555 Use the specified synchronized snapshot when making a dump of the
556 database (see Table 9.82 for more details).
557 This option is useful when needing to synchronize the dump with a
559 logical replication slot (see Chapter 49) or with a concurrent
560 session.
561 In the case of a parallel dump, the snapshot name defined by this
563 option is used rather than taking a new snapshot.
564 --strict-names
566 Require that each schema (-n/--schema) and table (-t/--table)
567 qualifier match at least one schema/table in the database to be
568 dumped. Note that if none of the schema/table qualifiers find
569 matches, pg_dump will generate an error even without
570 --strict-names.
571 This option has no effect on -N/--exclude-schema,
573 -T/--exclude-table, or --exclude-table-data. An exclude pattern
574 failing to match any objects is not considered an error.
575 --use-set-session-authorization
577 Output SQL-standard SET SESSION AUTHORIZATION commands instead of
578 ALTER OWNER commands to determine object ownership. This makes the
579 dump more standards-compatible, but depending on the history of the
580 objects in the dump, might not restore properly. Also, a dump using
581 SET SESSION AUTHORIZATION will certainly require superuser
582 privileges to restore correctly, whereas ALTER OWNER requires
583 lesser privileges.
584 -?
586 --help
587 Show help about pg_dump command line arguments, and exit.
588 The following command-line options control the database connection
590 parameters.
591 -d dbname
593 --dbname=dbname
594 Specifies the name of the database to connect to. This is
595 equivalent to specifying dbname as the first non-option argument on
596 the command line.
597 If this parameter contains an = sign or starts with a valid URI
599 prefix (postgresql:// or postgres://), it is treated as a conninfo
600 string. See Section 34.1 for more information.
601 -h host
603 --host=host
604 Specifies the host name of the machine on which the server is
605 running. If the value begins with a slash, it is used as the
606 directory for the Unix domain socket. The default is taken from the
607 PGHOST environment variable, if set, else a Unix domain socket
608 connection is attempted.
609 -p port
611 --port=port
612 Specifies the TCP port or local Unix domain socket file extension
613 on which the server is listening for connections. Defaults to the
614 PGPORT environment variable, if set, or a compiled-in default.
615 -U username
617 --username=username
618 User name to connect as.
619 -w
621 --no-password
622 Never issue a password prompt. If the server requires password
623 authentication and a password is not available by other means such
624 as a .pgpass file, the connection attempt will fail. This option
625 can be useful in batch jobs and scripts where no user is present to
626 enter a password.
627 -W
629 --password
630 Force pg_dump to prompt for a password before connecting to a
631 database.
632 This option is never essential, since pg_dump will automatically
634 prompt for a password if the server demands password
635 authentication. However, pg_dump will waste a connection attempt
636 finding out that the server wants a password. In some cases it is
637 worth typing -W to avoid the extra connection attempt.
638 --role=rolename
640 Specifies a role name to be used to create the dump. This option
641 causes pg_dump to issue a SET ROLE rolename command after
642 connecting to the database. It is useful when the authenticated
643 user (specified by -U) lacks privileges needed by pg_dump, but can
644 switch to a role with the required rights. Some installations have
645 a policy against logging in directly as a superuser, and use of
646 this option allows dumps to be made without violating the policy.
647
649 PGDATABASE
650 PGHOST
651 PGOPTIONS
652 PGPORT
653 PGUSER
654 Default connection parameters.
655 This utility, like most other PostgreSQL utilities, also uses the
657 environment variables supported by libpq (see Section 34.14).
658
660 pg_dump internally executes SELECT statements. If you have problems
661 running pg_dump, make sure you are able to select information from the
662 database using, for example, psql(1). Also, any default connection
663 settings and environment variables used by the libpq front-end library
664 will apply.
665 The database activity of pg_dump is normally collected by the
667 statistics collector. If this is undesirable, you can set parameter
668 track_counts to false via PGOPTIONS or the ALTER USER command.
669
671 If your database cluster has any local additions to the template1
672 database, be careful to restore the output of pg_dump into a truly
673 empty database; otherwise you are likely to get errors due to duplicate
674 definitions of the added objects. To make an empty database without any
675 local additions, copy from template0 not template1, for example:
676 CREATE DATABASE foo WITH TEMPLATE template0;
678 When a data-only dump is chosen and the option --disable-triggers is
680 used, pg_dump emits commands to disable triggers on user tables before
681 inserting the data, and then commands to re-enable them after the data
682 has been inserted. If the restore is stopped in the middle, the system
683 catalogs might be left in the wrong state.
684 The dump file produced by pg_dump does not contain the statistics used
686 by the optimizer to make query planning decisions. Therefore, it is
687 wise to run ANALYZE after restoring from a dump file to ensure optimal
688 performance; see Section 24.1.3 and Section 24.1.6 for more
689 information.
690 Because pg_dump is used to transfer data to newer versions of
692 PostgreSQL, the output of pg_dump can be expected to load into
693 PostgreSQL server versions newer than pg_dump's version. pg_dump can
694 also dump from PostgreSQL servers older than its own version.
695 (Currently, servers back to version 8.0 are supported.) However,
696 pg_dump cannot dump from PostgreSQL servers newer than its own major
697 version; it will refuse to even try, rather than risk making an invalid
698 dump. Also, it is not guaranteed that pg_dump's output can be loaded
699 into a server of an older major version — not even if the dump was
700 taken from a server of that version. Loading a dump file into an older
701 server may require manual editing of the dump file to remove syntax not
702 understood by the older server. Use of the --quote-all-identifiers
703 option is recommended in cross-version cases, as it can prevent
704 problems arising from varying reserved-word lists in different
705 PostgreSQL versions.
706 When dumping logical replication subscriptions, pg_dump will generate
708 CREATE SUBSCRIPTION commands that use the connect = false option, so
709 that restoring the subscription does not make remote connections for
710 creating a replication slot or for initial table copy. That way, the
711 dump can be restored without requiring network access to the remote
712 servers. It is then up to the user to reactivate the subscriptions in a
713 suitable way. If the involved hosts have changed, the connection
714 information might have to be changed. It might also be appropriate to
715 truncate the target tables before initiating a new full table copy.
716
718 To dump a database called mydb into a SQL-script file:
719 $ pg_dump mydb > db.sql
721 To reload such a script into a (freshly created) database named newdb:
723 $ psql -d newdb -f db.sql
725 To dump a database into a custom-format archive file:
727 $ pg_dump -Fc mydb > db.dump
729 To dump a database into a directory-format archive:
731 $ pg_dump -Fd mydb -f dumpdir
733 To dump a database into a directory-format archive in parallel with 5
735 worker jobs:
736 $ pg_dump -Fd mydb -j 5 -f dumpdir
738 To reload an archive file into a (freshly created) database named
740 newdb:
741 $ pg_restore -d newdb db.dump
743 To reload an archive file into the same database it was dumped from,
745 discarding the current contents of that database:
746 $ pg_restore -d postgres --clean --create db.dump
748 To dump a single table named mytab:
750 $ pg_dump -t mytab mydb > db.sql
752 To dump all tables whose names start with emp in the detroit schema,
754 except for the table named employee_log:
755 $ pg_dump -t 'detroit.emp*' -T detroit.employee_log mydb > db.sql
757 To dump all schemas whose names start with east or west and end in gsm,
759 excluding any schemas whose names contain the word test:
760 $ pg_dump -n 'east*gsm' -n 'west*gsm' -N '*test*' mydb > db.sql
762 The same, using regular expression notation to consolidate the
764 switches:
765 $ pg_dump -n '(east|west)*gsm' -N '*test*' mydb > db.sql
767 To dump all database objects except for tables whose names begin with
769 ts_:
770 $ pg_dump -T 'ts_*' mydb > db.sql
772 To specify an upper-case or mixed-case name in -t and related switches,
774 you need to double-quote the name; else it will be folded to lower case
775 (see Patterns). But double quotes are special to the shell, so in turn
776 they must be quoted. Thus, to dump a single table with a mixed-case
777 name, you need something like
778 $ pg_dump -t "\"MixedCaseName\"" mydb > mytab.sql
780
782 pg_dumpall(1), pg_restore(1), psql(1)
783PostgreSQL 11.3 2019 PG_DUMP(1)