1PG_DUMP(1)              PostgreSQL 9.2.24 Documentation             PG_DUMP(1)
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3
4

NAME

6       pg_dump - extract a PostgreSQL database into a script file or other
7       archive file
8

SYNOPSIS

10       pg_dump [connection-option...] [option...] [dbname]
11

DESCRIPTION

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
18       Dumps can be output in script or archive file formats. Script dumps are
19       plain-text files containing the SQL commands required to reconstruct
20       the database to the state it was in at the time it was saved. To
21       restore from such a script, feed it to psql(1). Script files can be
22       used to reconstruct the database even on other machines and other
23       architectures; with some modifications, even on other SQL database
24       products.
25
26       The alternative archive file formats must be used with pg_restore(1) to
27       rebuild the database. They allow pg_restore to be selective about what
28       is restored, or even to reorder the items prior to being restored. The
29       archive file formats are designed to be portable across architectures.
30
31       When used with one of the archive file formats and combined with
32       pg_restore, pg_dump provides a flexible archival and transfer
33       mechanism.  pg_dump can be used to backup an entire database, then
34       pg_restore can be used to examine the archive and/or select which parts
35       of the database are to be restored. The most flexible output file
36       format is the “custom” format (-Fc). It allows for selection and
37       reordering of all archived items, and is compressed by default.
38
39       While running pg_dump, one should examine the output for any warnings
40       (printed on standard error), especially in light of the limitations
41       listed below.
42

OPTIONS

44       The following command-line options control the content and format of
45       the output.
46
47       dbname
48           Specifies the name of the database to be dumped. If this is not
49           specified, the environment variable PGDATABASE is used. If that is
50           not set, the user name specified for the connection is used.
51
52       -a, --data-only
53           Dump only the data, not the schema (data definitions). Table data,
54           large objects, and sequence values are dumped.
55
56           This option is similar to, but for historical reasons not identical
57           to, specifying --section=data.
58
59       -b, --blobs
60           Include large objects in the dump. This is the default behavior
61           except when --schema, --table, or --schema-only is specified. The
62           -b switch is therefore only useful to add large objects to dumps
63           where a specific schema or table has been requested. Note that
64           blobs are considered data and therefore will be included when
65           --data-only is used, but not when --schema-only is.
66
67       -c, --clean
68           Output commands to clean (drop) database objects prior to
69           outputting the commands for creating them. (Restore might generate
70           some harmless error messages, if any objects were not present in
71           the destination database.)
72
73           This option is only meaningful for the plain-text format. For the
74           archive formats, you can specify the option when you call
75           pg_restore.
76
77       -C, --create
78           Begin the output with a command to create the database itself and
79           reconnect to the created database. (With a script of this form, it
80           doesn't matter which database in the destination installation you
81           connect to before running the script.) If --clean is also
82           specified, the script drops and recreates the target database
83           before reconnecting to it.
84
85           This option is only meaningful for the plain-text format. For the
86           archive formats, you can specify the option when you call
87           pg_restore.
88
89       -E encoding, --encoding=encoding
90           Create the dump in the specified character set encoding. By
91           default, the dump is created in the database encoding. (Another way
92           to get the same result is to set the PGCLIENTENCODING environment
93           variable to the desired dump encoding.)
94
95       -f file, --file=file
96           Send output to the specified file. This parameter can be omitted
97           for file based output formats, in which case the standard output is
98           used. It must be given for the directory output format however,
99           where it specifies the target directory instead of a file. In this
100           case the directory is created by pg_dump and must not exist before.
101
102       -F format, --format=format
103           Selects the format of the output.  format can be one of the
104           following:
105
106           p, plain
107               Output a plain-text SQL script file (the default).
108
109           c, custom
110               Output a custom-format archive suitable for input into
111               pg_restore. Together with the directory output format, this is
112               the most flexible output format in that it allows manual
113               selection and reordering of archived items during restore. This
114               format is also compressed by default.
115
116           d, directory
117               Output a directory-format archive suitable for input into
118               pg_restore. This will create a directory with one file for each
119               table and blob being dumped, plus a so-called Table of Contents
120               file describing the dumped objects in a machine-readable format
121               that pg_restore can read. A directory format archive can be
122               manipulated with standard Unix tools; for example, files in an
123               uncompressed archive can be compressed with the gzip tool. This
124               format is compressed by default.
125
126           t, tar
127               Output a tar-format archive suitable for input into pg_restore.
128               The tar format is compatible with the directory format:
129               extracting a tar-format archive produces a valid
130               directory-format archive. However, the tar format does not
131               support compression. Also, when using tar format the relative
132               order of table data items cannot be changed during restore.
133
134       -i, --ignore-version
135           A deprecated option that is now ignored.
136
137       -n schema, --schema=schema
138           Dump only schemas matching schema; this selects both the schema
139           itself, and all its contained objects. When this option is not
140           specified, all non-system schemas in the target database will be
141           dumped. Multiple schemas can be selected by writing multiple -n
142           switches. Also, the schema parameter is interpreted as a pattern
143           according to the same rules used by psql's \d commands (see
144           Patterns), so multiple schemas can also be selected by writing
145           wildcard characters in the pattern. When using wildcards, be
146           careful to quote the pattern if needed to prevent the shell from
147           expanding the wildcards; see EXAMPLES.
148
149               Note
150               When -n is specified, pg_dump makes no attempt to dump any
151               other database objects that the selected schema(s) might depend
152               upon. Therefore, there is no guarantee that the results of a
153               specific-schema dump can be successfully restored by themselves
154               into a clean database.
155
156               Note
157               Non-schema objects such as blobs are not dumped when -n is
158               specified. You can add blobs back to the dump with the --blobs
159               switch.
160
161       -N schema, --exclude-schema=schema
162           Do not dump any schemas matching the schema pattern. The pattern is
163           interpreted according to the same rules as for -n.  -N can be given
164           more than once to exclude schemas matching any of several patterns.
165
166           When both -n and -N are given, the behavior is to dump just the
167           schemas that match at least one -n switch but no -N switches. If -N
168           appears without -n, then schemas matching -N are excluded from what
169           is otherwise a normal dump.
170
171       -o, --oids
172           Dump object identifiers (OIDs) as part of the data for every table.
173           Use this option if your application references the OID columns in
174           some way (e.g., in a foreign key constraint). Otherwise, this
175           option should not be used.
176
177       -O, --no-owner
178           Do not output commands to set ownership of objects to match the
179           original database. By default, pg_dump issues ALTER OWNER or SET
180           SESSION AUTHORIZATION statements to set ownership of created
181           database objects. These statements will fail when the script is run
182           unless it is started by a superuser (or the same user that owns all
183           of the objects in the script). To make a script that can be
184           restored by any user, but will give that user ownership of all the
185           objects, specify -O.
186
187           This option is only meaningful for the plain-text format. For the
188           archive formats, you can specify the option when you call
189           pg_restore.
190
191       -R, --no-reconnect
192           This option is obsolete but still accepted for backwards
193           compatibility.
194
195       -s, --schema-only
196           Dump only the object definitions (schema), not data.
197
198           This option is the inverse of --data-only. It is similar to, but
199           for historical reasons not identical to, specifying
200           --section=pre-data --section=post-data.
201
202           (Do not confuse this with the --schema option, which uses the word
203           “schema” in a different meaning.)
204
205           To exclude table data for only a subset of tables in the database,
206           see --exclude-table-data.
207
208       -S username, --superuser=username
209           Specify the superuser user name to use when disabling triggers.
210           This is only relevant if --disable-triggers is used. (Usually, it's
211           better to leave this out, and instead start the resulting script as
212           superuser.)
213
214       -t table, --table=table
215           Dump only tables (or views or sequences or foreign tables) matching
216           table. Multiple tables can be selected by writing multiple -t
217           switches. Also, the table parameter is interpreted as a pattern
218           according to the same rules used by psql's \d commands (see
219           Patterns), so multiple tables can also be selected by writing
220           wildcard characters in the pattern. When using wildcards, be
221           careful to quote the pattern if needed to prevent the shell from
222           expanding the wildcards; see EXAMPLES.
223
224           The -n and -N switches have no effect when -t is used, because
225           tables selected by -t will be dumped regardless of those switches,
226           and non-table objects will not be dumped.
227
228               Note
229               When -t is specified, pg_dump makes no attempt to dump any
230               other database objects that the selected table(s) might depend
231               upon. Therefore, there is no guarantee that the results of a
232               specific-table dump can be successfully restored by themselves
233               into a clean database.
234
235               Note
236               The behavior of the -t switch is not entirely upward compatible
237               with pre-8.2 PostgreSQL versions. Formerly, writing -t tab
238               would dump all tables named tab, but now it just dumps
239               whichever one is visible in your default search path. To get
240               the old behavior you can write -t '*.tab'. Also, you must write
241               something like -t sch.tab to select a table in a particular
242               schema, rather than the old locution of -n sch -t tab.
243
244       -T table, --exclude-table=table
245           Do not dump any tables matching the table pattern. The pattern is
246           interpreted according to the same rules as for -t.  -T can be given
247           more than once to exclude tables matching any of several patterns.
248
249           When both -t and -T are given, the behavior is to dump just the
250           tables that match at least one -t switch but no -T switches. If -T
251           appears without -t, then tables matching -T are excluded from what
252           is otherwise a normal dump.
253
254       -v, --verbose
255           Specifies verbose mode. This will cause pg_dump to output detailed
256           object comments and start/stop times to the dump file, and progress
257           messages to standard error.
258
259       -V, --version
260           Print the pg_dump version and exit.
261
262       -x, --no-privileges, --no-acl
263           Prevent dumping of access privileges (grant/revoke commands).
264
265       -Z 0..9, --compress=0..9
266           Specify the compression level to use. Zero means no compression.
267           For the custom archive format, this specifies compression of
268           individual table-data segments, and the default is to compress at a
269           moderate level. For plain text output, setting a nonzero
270           compression level causes the entire output file to be compressed,
271           as though it had been fed through gzip; but the default is not to
272           compress. The tar archive format currently does not support
273           compression at all.
274
275       --binary-upgrade
276           This option is for use by in-place upgrade utilities. Its use for
277           other purposes is not recommended or supported. The behavior of the
278           option may change in future releases without notice.
279
280       --column-inserts, --attribute-inserts
281           Dump data as INSERT commands with explicit column names (INSERT
282           INTO table (column, ...) VALUES ...). This will make restoration
283           very slow; it is mainly useful for making dumps that can be loaded
284           into non-PostgreSQL databases. However, since this option generates
285           a separate command for each row, an error in reloading a row causes
286           only that row to be lost rather than the entire table contents.
287
288       --disable-dollar-quoting
289           This option disables the use of dollar quoting for function bodies,
290           and forces them to be quoted using SQL standard string syntax.
291
292       --disable-triggers
293           This option is only relevant when creating a data-only dump. It
294           instructs pg_dump to include commands to temporarily disable
295           triggers on the target tables while the data is reloaded. Use this
296           if you have referential integrity checks or other triggers on the
297           tables that you do not want to invoke during data reload.
298
299           Presently, the commands emitted for --disable-triggers must be done
300           as superuser. So, you should also specify a superuser name with -S,
301           or preferably be careful to start the resulting script as a
302           superuser.
303
304           This option is only meaningful for the plain-text format. For the
305           archive formats, you can specify the option when you call
306           pg_restore.
307
308       --exclude-table-data=table
309           Do not dump data for any tables matching the table pattern. The
310           pattern is interpreted according to the same rules as for -t.
311           --exclude-table-data can be given more than once to exclude tables
312           matching any of several patterns. This option is useful when you
313           need the definition of a particular table even though you do not
314           need the data in it.
315
316           To exclude data for all tables in the database, see --schema-only.
317
318       --inserts
319           Dump data as INSERT commands (rather than COPY). This will make
320           restoration very slow; it is mainly useful for making dumps that
321           can be loaded into non-PostgreSQL databases. However, since this
322           option generates a separate command for each row, an error in
323           reloading a row causes only that row to be lost rather than the
324           entire table contents. Note that the restore might fail altogether
325           if you have rearranged column order. The --column-inserts option is
326           safe against column order changes, though even slower.
327
328       --lock-wait-timeout=timeout
329           Do not wait forever to acquire shared table locks at the beginning
330           of the dump. Instead fail if unable to lock a table within the
331           specified timeout. The timeout may be specified in any of the
332           formats accepted by SET statement_timeout. (Allowed values vary
333           depending on the server version you are dumping from, but an
334           integer number of milliseconds is accepted by all versions since
335           7.3. This option is ignored when dumping from a pre-7.3 server.)
336
337       --no-security-labels
338           Do not dump security labels.
339
340       --no-tablespaces
341           Do not output commands to select tablespaces. With this option, all
342           objects will be created in whichever tablespace is the default
343           during restore.
344
345           This option is only meaningful for the plain-text format. For the
346           archive formats, you can specify the option when you call
347           pg_restore.
348
349       --no-unlogged-table-data
350           Do not dump the contents of unlogged tables. This option has no
351           effect on whether or not the table definitions (schema) are dumped;
352           it only suppresses dumping the table data. Data in unlogged tables
353           is always excluded when dumping from a standby server.
354
355       --quote-all-identifiers
356           Force quoting of all identifiers. This option is recommended when
357           dumping a database from a server whose PostgreSQL major version is
358           different from pg_dump's, or when the output is intended to be
359           loaded into a server of a different major version. By default,
360           pg_dump quotes only identifiers that are reserved words in its own
361           major version. This sometimes results in compatibility issues when
362           dealing with servers of other versions that may have slightly
363           different sets of reserved words. Using --quote-all-identifiers
364           prevents such issues, at the price of a harder-to-read dump script.
365
366       --section=sectionname
367           Only dump the named section. The section name can be pre-data,
368           data, or post-data. This option can be specified more than once to
369           select multiple sections. The default is to dump all sections.
370
371           The data section contains actual table data, large-object contents,
372           and sequence values. Post-data items include definitions of
373           indexes, triggers, rules, and constraints other than validated
374           check constraints. Pre-data items include all other data definition
375           items.
376
377       --serializable-deferrable
378           Use a serializable transaction for the dump, to ensure that the
379           snapshot used is consistent with later database states; but do this
380           by waiting for a point in the transaction stream at which no
381           anomalies can be present, so that there isn't a risk of the dump
382           failing or causing other transactions to roll back with a
383           serialization_failure. See Chapter 13, Concurrency Control, in the
384           documentation for more information about transaction isolation and
385           concurrency control.
386
387           This option is not beneficial for a dump which is intended only for
388           disaster recovery. It could be useful for a dump used to load a
389           copy of the database for reporting or other read-only load sharing
390           while the original database continues to be updated. Without it the
391           dump may reflect a state which is not consistent with any serial
392           execution of the transactions eventually committed. For example, if
393           batch processing techniques are used, a batch may show as closed in
394           the dump without all of the items which are in the batch appearing.
395
396           This option will make no difference if there are no read-write
397           transactions active when pg_dump is started. If read-write
398           transactions are active, the start of the dump may be delayed for
399           an indeterminate length of time. Once running, performance with or
400           without the switch is the same.
401
402       --use-set-session-authorization
403           Output SQL-standard SET SESSION AUTHORIZATION commands instead of
404           ALTER OWNER commands to determine object ownership. This makes the
405           dump more standards-compatible, but depending on the history of the
406           objects in the dump, might not restore properly. Also, a dump using
407           SET SESSION AUTHORIZATION will certainly require superuser
408           privileges to restore correctly, whereas ALTER OWNER requires
409           lesser privileges.
410
411       -?, --help
412           Show help about pg_dump command line arguments, and exit.
413
414       The following command-line options control the database connection
415       parameters.
416
417       -h host, --host=host
418           Specifies the host name of the machine on which the server is
419           running. If the value begins with a slash, it is used as the
420           directory for the Unix domain socket. The default is taken from the
421           PGHOST environment variable, if set, else a Unix domain socket
422           connection is attempted.
423
424       -p port, --port=port
425           Specifies the TCP port or local Unix domain socket file extension
426           on which the server is listening for connections. Defaults to the
427           PGPORT environment variable, if set, or a compiled-in default.
428
429       -U username, --username=username
430           User name to connect as.
431
432       -w, --no-password
433           Never issue a password prompt. If the server requires password
434           authentication and a password is not available by other means such
435           as a .pgpass file, the connection attempt will fail. This option
436           can be useful in batch jobs and scripts where no user is present to
437           enter a password.
438
439       -W, --password
440           Force pg_dump to prompt for a password before connecting to a
441           database.
442
443           This option is never essential, since pg_dump will automatically
444           prompt for a password if the server demands password
445           authentication. However, pg_dump will waste a connection attempt
446           finding out that the server wants a password. In some cases it is
447           worth typing -W to avoid the extra connection attempt.
448
449       --role=rolename
450           Specifies a role name to be used to create the dump. This option
451           causes pg_dump to issue a SET ROLErolename command after connecting
452           to the database. It is useful when the authenticated user
453           (specified by -U) lacks privileges needed by pg_dump, but can
454           switch to a role with the required rights. Some installations have
455           a policy against logging in directly as a superuser, and use of
456           this option allows dumps to be made without violating the policy.
457

ENVIRONMENT

459       PGDATABASE, PGHOST, PGOPTIONS, PGPORT, PGUSER
460           Default connection parameters.
461
462       This utility, like most other PostgreSQL utilities, also uses the
463       environment variables supported by libpq (see Section 31.14,
464       “Environment Variables”, in the documentation).
465

DIAGNOSTICS

467       pg_dump internally executes SELECT statements. If you have problems
468       running pg_dump, make sure you are able to select information from the
469       database using, for example, psql(1). Also, any default connection
470       settings and environment variables used by the libpq front-end library
471       will apply.
472
473       The database activity of pg_dump is normally collected by the
474       statistics collector. If this is undesirable, you can set parameter
475       track_counts to false via PGOPTIONS or the ALTER USER command.
476

NOTES

478       If your database cluster has any local additions to the template1
479       database, be careful to restore the output of pg_dump into a truly
480       empty database; otherwise you are likely to get errors due to duplicate
481       definitions of the added objects. To make an empty database without any
482       local additions, copy from template0 not template1, for example:
483
484           CREATE DATABASE foo WITH TEMPLATE template0;
485
486       When a data-only dump is chosen and the option --disable-triggers is
487       used, pg_dump emits commands to disable triggers on user tables before
488       inserting the data, and then commands to re-enable them after the data
489       has been inserted. If the restore is stopped in the middle, the system
490       catalogs might be left in the wrong state.
491
492       The dump file produced by pg_dump does not contain the statistics used
493       by the optimizer to make query planning decisions. Therefore, it is
494       wise to run ANALYZE after restoring from a dump file to ensure optimal
495       performance; see Section 23.1.3, “Updating Planner Statistics”, in the
496       documentation and Section 23.1.6, “The Autovacuum Daemon”, in the
497       documentation for more information. The dump file also does not contain
498       any ALTER DATABASE ... SET commands; these settings are dumped by
499       pg_dumpall(1), along with database users and other installation-wide
500       settings.
501
502       Because pg_dump is used to transfer data to newer versions of
503       PostgreSQL, the output of pg_dump can be expected to load into
504       PostgreSQL server versions newer than pg_dump's version.  pg_dump can
505       also dump from PostgreSQL servers older than its own version.
506       (Currently, servers back to version 7.0 are supported.) However,
507       pg_dump cannot dump from PostgreSQL servers newer than its own major
508       version; it will refuse to even try, rather than risk making an invalid
509       dump. Also, it is not guaranteed that pg_dump's output can be loaded
510       into a server of an older major version — not even if the dump was
511       taken from a server of that version. Loading a dump file into an older
512       server may require manual editing of the dump file to remove syntax not
513       understood by the older server. Use of the --quote-all-identifiers
514       option is recommended in cross-version cases, as it can prevent
515       problems arising from varying reserved-word lists in different
516       PostgreSQL versions.
517

EXAMPLES

519       To dump a database called mydb into a SQL-script file:
520
521           $ pg_dump mydb > db.sql
522
523       To reload such a script into a (freshly created) database named newdb:
524
525           $ psql -d newdb -f db.sql
526
527       To dump a database into a custom-format archive file:
528
529           $ pg_dump -Fc mydb > db.dump
530
531       To dump a database into a directory-format archive:
532
533           $ pg_dump -Fd mydb -f dumpdir
534
535       To reload an archive file into a (freshly created) database named
536       newdb:
537
538           $ pg_restore -d newdb db.dump
539
540       To dump a single table named mytab:
541
542           $ pg_dump -t mytab mydb > db.sql
543
544       To dump all tables whose names start with emp in the detroit schema,
545       except for the table named employee_log:
546
547           $ pg_dump -t 'detroit.emp*' -T detroit.employee_log mydb > db.sql
548
549       To dump all schemas whose names start with east or west and end in gsm,
550       excluding any schemas whose names contain the word test:
551
552           $ pg_dump -n 'east*gsm' -n 'west*gsm' -N '*test*' mydb > db.sql
553
554       The same, using regular expression notation to consolidate the
555       switches:
556
557           $ pg_dump -n '(east|west)*gsm' -N '*test*' mydb > db.sql
558
559       To dump all database objects except for tables whose names begin with
560       ts_:
561
562           $ pg_dump -T 'ts_*' mydb > db.sql
563
564       To specify an upper-case or mixed-case name in -t and related switches,
565       you need to double-quote the name; else it will be folded to lower case
566       (see Patterns). But double quotes are special to the shell, so in turn
567       they must be quoted. Thus, to dump a single table with a mixed-case
568       name, you need something like
569
570           $ pg_dump -t '"MixedCaseName"' mydb > mytab.sql
571

SEE ALSO

573       pg_dumpall(1), pg_restore(1), psql(1)
574
575
576
577PostgreSQL 9.2.24                 2017-11-06                        PG_DUMP(1)
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