PG_DUMP(1)

📦 version 15.19, in opensuse-leap 16.0

💾 pg_dump — the PG_DUMP(1) manual, but make it make sense ✨

Okay so this is the PostgreSQL 15.19 Documentation version of the page, bestie, and we're folding the manual name in right here so you know exactly what's up: PG_DUMP(1). Let's get into it 💅

🏷️ NAME

pg_dump — extract a PostgreSQL database into a script file or other archive file 🫶

🧾 SYNOPSIS

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

🌸 DESCRIPTION

Okay so pg_dump is the utility for backing up a PostgreSQL database. It makes consistent backups even if the database is being used concurrently. And no cap: pg_dump does not block other users accessing the database — readers or writers, neither one. Slay.

pg_dump only dumps a single database. If you wanna back up an entire cluster, or back up global objects that are common to all databases in a cluster — like roles and tablespaces — use pg_dumpall(1). That's the cluster-wide bestie, okay?

Dumps can be output in script or archive file formats. Script dumps are plain-text files containing the SQL commands required to reconstruct the database to the state it was in at the time it was saved. To restore from such a script, feed it to psql(1). Script files can be used to reconstruct the database even on other machines and other architectures; with some modifications, even on other SQL database products. Iconic portability behavior, honestly.

The alternative archive file formats must be used with pg_restore(1) to rebuild the database. They allow pg_restore to be selective about what is restored, or even to reorder the items prior to being restored. The archive file formats are designed to be portable across architectures. Obsessed with the flexibility.

When used with one of the archive file formats and combined with pg_restore, pg_dump provides a flexible archival and transfer mechanism. pg_dump can be used to backup an entire database, then pg_restore can be used to examine the archive and/or select which parts of the database are to be restored. The most flexible output file formats are the “custom” format (-Fc) and the “directory” format (-Fd). They allow for selection and reordering of all archived items, support parallel restoration, and are compressed by default. The “directory” format is the only format that supports parallel dumps. Periodt.

While running pg_dump, one should examine the output for any warnings (printed on standard error), especially in light of the limitations listed below. Like, actually look at the warnings, bestie 😭

⚠️ Warning — Restoring a dump causes the destination to execute arbitrary code of the source superusers' choice. Partial dumps and partial restores do not limit that. If the source superusers are not trusted, the dumped SQL statements must be inspected before restoring. Non-plain-text dumps can be inspected by using pg_restore's --file option. Note that the client running the dump and restore need not trust the source or destination superusers. This is the serious one — do not skip the vibe check here 💀

🛠️ OPTIONS

The following command-line options control the content and format of the output. Okay, let's go option by option, bestie 🎀

  • dbname — Specifies the name of the database to be dumped. If this is not specified, the environment variable PGDATABASE is used. If that is not set, the user name specified for the connection is used.
  • -a, --data-only — Dump only the data, not the schema (data definitions). Table data, large objects, and sequence values are dumped. This option is similar to, but for historical reasons not identical to, specifying --section=data. Historical beef, don't ask 💅
  • -b, --blobs — Include large objects in the dump. This is the default behavior except when --schema, --table, or --schema-only is specified. The -b switch is therefore only useful to add large objects to dumps where a specific schema or table has been requested. Note that blobs are considered data and therefore will be included when --data-only is used, but not when --schema-only is.
  • -B, --no-blobs — Exclude large objects in the dump. When both -b and -B are given, the behavior is to output large objects, when data is being dumped, see the -b documentation. So yes, -b wins that little fight 🫶
  • -c, --clean — Output commands to DROP all the dumped database objects prior to outputting the commands for creating them. This option is useful when the restore is to overwrite an existing database. If any of the objects do not exist in the destination database, ignorable error messages will be reported during restore, unless --if-exists is also specified. This option is ignored when emitting an archive (non-text) output file. For the archive formats, you can specify the option when you call pg_restore. Archive formats are like “not my problem, tell pg_restore” 😌
  • -C, --create — Begin the output with a command to create the database itself and reconnect to the created database. (With a script of this form, it doesn't matter which database in the destination installation you connect to before running the script.) If --clean is also specified, the script drops and recreates the target database before reconnecting to it. With --create, the output also includes the database's comment if any, and any configuration variable settings that are specific to this database, that is, any ALTER DATABASE ... SET ... and ALTER ROLE ... IN DATABASE ... SET ... commands that mention this database. Access privileges for the database itself are also dumped, unless --no-acl is specified. This option is ignored when emitting an archive (non-text) output file. For the archive formats, you can specify the option when you call pg_restore.
  • -e pattern, --extension=pattern — Dump only extensions matching pattern. When this option is not specified, all non-system extensions in the target database will be dumped. Multiple extensions can be selected by writing multiple -e switches. The pattern parameter is interpreted as a pattern according to the same rules used by psql's \d commands (see Patterns), so multiple extensions can also be selected by writing wildcard characters in the pattern. When using wildcards, be careful to quote the pattern if needed to prevent the shell from expanding the wildcards. Shell expansion is not the moment, bestie 😭 Any configuration relation registered by pg_extension_config_dump is included in the dump if its extension is specified by --extension.
📝 Note — When -e is specified, pg_dump makes no attempt to dump any other database objects that the selected extension(s) might depend upon. Therefore, there is no guarantee that the results of a specific-extension dump can be successfully restored by themselves into a clean database. Like, it's giving “partial extension dump has main character energy but no safety net” 💀
  • -E encoding, --encoding=encoding — Create the dump in the specified character set encoding. By default, the dump is created in the database encoding. (Another way to get the same result is to set the PGCLIENTENCODING environment variable to the desired dump encoding.) The supported encodings are described in Section 24.3.1.
  • -f file, --file=file — Send output to the specified file. This parameter can be omitted for file based output formats, in which case the standard output is used. It must be given for the directory output format however, where it specifies the target directory instead of a file. In this case the directory is created by pg_dump and must not exist before. So don't pre-create it and then act surprised, okay? 🙈
  • -F format, --format=format — Selects the format of the output. format can be one of the following:
    • p / plain — Output a plain-text SQL script file (the default).
    • c / custom — Output a custom-format archive suitable for input into pg_restore. Together with the directory output format, this is the most flexible output format in that it allows manual selection and reordering of archived items during restore. This format is also compressed by default. Flexible and compressed, we love a multitasker 💖
    • d / directory — Output a directory-format archive suitable for input into pg_restore. This will create a directory with one file for each table and blob being dumped, plus a so-called Table of Contents file describing the dumped objects in a machine-readable format that pg_restore can read. A directory format archive can be manipulated with standard Unix tools; for example, files in an uncompressed archive can be compressed with the gzip tool. This format is compressed by default and also supports parallel dumps. The only format with parallel dump support — main character behavior 👑
    • t / tar — Output a tar-format archive suitable for input into pg_restore. The tar format is compatible with the directory format: extracting a tar-format archive produces a valid directory-format archive. However, the tar format does not support compression. Also, when using tar format the relative order of table data items cannot be changed during restore. No compression and no reordering, so know that before you commit 🎀
  • -j njobs, --jobs=njobs — Run the dump in parallel by dumping njobs tables simultaneously. This option may reduce the time needed to perform the dump but it also increases the load on the database server. You can only use this option with the directory output format because this is the only output format where multiple processes can write their data at the same time. pg_dump will open njobs + 1 connections to the database, so make sure your max_connections setting is high enough to accommodate all connections. Like, check your connection budget first, bestie 🫶 Requesting exclusive locks on database objects while running a parallel dump could cause the dump to fail. The reason is that the pg_dump leader process requests shared locks (ACCESS SHARE) on the objects that the worker processes are going to dump later in order to make sure that nobody deletes them and makes them go away while the dump is running. If another client then requests an exclusive lock on a table, that lock will not be granted but will be queued waiting for the shared lock of the leader process to be released. Consequently any other access to the table will not be granted either and will queue after the exclusive lock request. This includes the worker process trying to dump the table. Without any precautions this would be a classic deadlock situation. To detect this conflict, the pg_dump worker process requests another shared lock using the NOWAIT option. If the worker process is not granted this shared lock, somebody else must have requested an exclusive lock in the meantime and there is no way to continue with the dump, so pg_dump has no choice but to abort the dump. Literally the deadlock lore — respect the locks, periodt 💅

To do a parallel dump, the database server has to support synchronized snapshots — a feature that showed up in PostgreSQL 9.2 for primary servers and in 10 for standbys 💫. With it, database clients can make sure they're all looking at the exact same data set even when they're on different connections. Like, pg_dump -j opens multiple database connections — it connects once with the leader process and then one more time for each worker job. Without synchronized snapshots, those worker jobs would have zero guarantee of seeing the same data on each connection, and bestie, that means an inconsistent backup. We don't do those. 💀

  • -n pattern, --schema=pattern — dump only the schemas matching pattern; this grabs both the schema itself and every object living inside it 🫶. If you don't use this option, all non-system schemas in the target database get dumped. You can select multiple schemas by writing multiple -n switches. The pattern parameter follows the same rules as psql's \d commands (peep Patterns below), so you can also pick multiple schemas by throwing wildcard characters into the pattern. When you're using wildcards, be careful to quote the pattern if needed so the shell doesn't expand them first — see Examples below.
Note 📌 When -n is specified, pg_dump makes no attempt to dump any other database objects that the selected schema(s) might depend upon. So there's no guarantee that a specific-schema dump can be successfully restored all by itself into a clean database. It's giving "you're on your own" energy. Note 📌 Non-schema objects like blobs are not dumped when -n is specified. You can add blobs back to the dump with the --blobs switch. iykyk 💅
  • -N pattern, --exclude-schema=pattern — do not dump any schemas matching pattern. The pattern follows the same rules as for -n. You can hand -N more than once to exclude schemas matching any of several patterns. When both -n and -N are given, the vibe is: dump just the schemas that match at least one -n switch but no -N switches. If -N shows up without -n, then schemas matching -N are excluded from what would otherwise be a normal dump ✨.
  • -O, --no-owner — don't output commands to set object ownership to match the original database. By default, pg_dump issues ALTER OWNER or SET SESSION AUTHORIZATION statements to set ownership of created database objects. Those statements will fail when the script is run unless it's started by a superuser (or the same user that owns all the objects in the script). So if you want a script that can be restored by any user — but will give that user ownership of all the objects — specify -O 👑. This option is ignored when emitting an archive (non-text) output file. For the archive formats, you can specify the option when you call pg_restore.
  • -R, --no-reconnect — this option is obsolete but still accepted for backwards compatibility. It's giving "vintage, but make it still work" 🙈.
  • -s, --schema-only — dump only the object definitions (schema), not the data. This option is the inverse of --data-only. It's similar to — but for historical reasons not identical to — specifying --section=pre-data --section=post-data. (Don't confuse this with the --schema option, which uses the word "schema" in a whole different meaning, okurrr 💅.) To exclude table data for only a subset of tables in the database, see --exclude-table-data.
  • -S username, --superuser=username — specify the superuser user name to use when disabling triggers. This is only relevant if --disable-triggers is used. (Usually it's better to leave this out, and instead start the resulting script as superuser. Trust. 💜)
  • -t pattern, --table=pattern — dump only tables with names matching pattern. Multiple tables can be selected by writing multiple -t switches. The pattern parameter is interpreted as a pattern according to the same rules used by psql's \d commands (see Patterns below), so multiple tables can also be selected by writing wildcard characters in the pattern 🌸. When using wildcards, be careful to quote the pattern if needed to prevent the shell from expanding the wildcards; see Examples below. As well as tables, this option can be used to dump the definition of matching views, materialized views, foreign tables, and sequences. It will not dump the contents of views or materialized views, and the contents of foreign tables will only be dumped if the corresponding foreign server is specified with --include-foreign-data. The -n and -N switches have no effect when -t is used, because tables selected by -t will be dumped regardless of those switches, and non-table objects will not be dumped.
Note 📌 When -t is specified, pg_dump makes no attempt to dump any other database objects that the selected table(s) might depend upon. So again — no guarantee that a specific-table dump can be successfully restored by itself into a clean database 😭.
  • -T pattern, --exclude-table=pattern — do not dump any tables matching pattern. The pattern is interpreted according to the same rules as for -t. -T can be given more than once to exclude tables matching any of several patterns. When both -t and -T are given, the behavior is to dump just the tables that match at least one -t switch but no -T switches. If -T appears without -t, then tables matching -T are excluded from what is otherwise a normal dump. Periodt 💫.
  • -v, --verbose — specifies verbose mode 🗣️. This causes pg_dump to output detailed object comments and start/stop times to the dump file, plus progress messages to standard error. Repeating the option causes additional debug-level messages to appear on standard error. So if you want maximum yappening, just keep stacking -vs.
  • -V, --version — print the pg_dump version and exit. Short, sweet, iconic ✨.
  • -x, --no-privileges, --no-acl — prevent dumping of access privileges (grant/revoke commands). No ACLs, no problem 🙅‍♀️.
  • -Z 0..9, --compress=0..9 — specify the compression level to use. Zero means no compression. For the custom and directory archive formats, this specifies compression of individual table-data segments, and the default is to compress at a moderate level 🔥. For plain text output, setting a nonzero compression level causes the entire output file to be compressed, as though it had been fed through gzip; but the default is not to compress. The tar archive format currently does not support compression at all — it's giving "we don't do that here" 💀.
  • --binary-upgrade — this option is for use by in-place upgrade utilities. Its use for other purposes is not recommended or supported. The behavior of the option may change in future releases without notice ⚠️. So like, don't just casually use this one, bestie.
  • --column-inserts, --attribute-inserts — dump data as INSERT commands with explicit column names (INSERT INTO table (column, ...) VALUES ...). This will make restoration very slow; it's mainly useful for making dumps that can be loaded into non-PostgreSQL databases. Any error during restoring will cause only rows that are part of the problematic INSERT to be lost, rather than the entire table contents. Silver lining, honestly 🦋.
  • --disable-dollar-quoting — disables the use of dollar quoting for function bodies, and forces them to be quoted using SQL standard string syntax. Bye dollar signs 💸.
  • --disable-triggers — this option is relevant only when creating a data-only dump. It tells pg_dump to include commands that temporarily disable triggers on the target tables while the data is restored. Use this if you have referential integrity checks or other triggers on the tables that you do not want to invoke during data restore 🙈. Presently, the commands emitted for --disable-triggers must be done as superuser. So you should also specify a superuser name with -S, or preferably be careful to start the resulting script as a superuser 👑. This option is ignored when emitting an archive (non-text) output file. For the archive formats, you can specify the option when you call pg_restore.
  • --enable-row-security — this option is relevant only when dumping the contents of a table that has row security. By default, pg_dump sets row_security to off, to ensure that all data is dumped from the table. If the user doesn't have sufficient privileges to bypass row security, then an error is thrown 💀. This parameter tells pg_dump to set row_security to on instead, allowing the user to dump the parts of the contents of the table that they have access to. Note that if you use this option currently, you probably also want the dump to be in INSERT format, since the COPY FROM during restore does not support row security. Just a lil heads up 🎀.
  • --exclude-table-data=pattern — do not dump data for any tables matching pattern. The pattern is interpreted according to the same rules as for -t. --exclude-table-data can be given more than once to exclude tables matching any of several patterns. This option is useful when you need the definition of a particular table even though you don't need the data in it 🙌. To exclude data for all tables in the database, see --schema-only.
  • --extra-float-digits=ndigits — use the specified value of extra_float_digits when dumping floating-point data, instead of the maximum available precision. Routine dumps made for backup purposes should not use this option — ngl, leave it alone unless you know exactly why you're here ⚠️.
  • --if-exists — use DROP ... IF EXISTS commands to drop objects in --clean mode. This suppresses "does not exist" errors that might otherwise be reported 🙅‍♀️. This option is not valid unless --clean is also specified. Gotta have the pair, bestie.
  • --include-foreign-data=foreignserver — dump the data for any foreign table with a foreign server matching the foreignserver pattern 🌍. Multiple foreign servers can be selected by writing multiple --include-foreign-data switches. Also, the foreignserver parameter is interpreted as a pattern according to the same rules used by psql's \d commands (see Patterns below), so multiple foreign servers can also be selected by writing wildcard characters in the pattern. When using wildcards, be careful to quote the pattern if needed to prevent the shell from expanding the wildcards; see Examples below. The only exception is that an empty pattern is disallowed — literally cannot be empty, no cap.
Note 💜 Using wildcards in --include-foreign-data may result in access to unexpected foreign servers. Also, to use this option securely, make sure that the named server must have a trusted owner.
Note 🫶 When --include-foreign-data is specified, pg_dump does not check that the foreign table is writable. Therefore, there is no guarantee that the results of a foreign table dump can be successfully restored. Like, none. Zero promises. 😭
  • --inserts — dumps the data as INSERT commands instead of COPY. Bestie, this makes restoration very slow — it's mainly useful for making dumps that can be loaded into non-PostgreSQL databases, iykyk. The upside: any error during restoring will cause only the rows that are part of the problematic INSERT to be lost, rather than the entire table contents. Heads up that the restore might fail altogether if you've rearranged column order 🙈. The --column-inserts option is safe against column order changes, though even slower.
  • --load-via-partition-root — when dumping data for a table partition, this makes the COPY or INSERT statements target the root of the partitioning hierarchy that contains it, rather than the partition itself. So the appropriate partition gets re-determined for each row when the data is loaded ✨. Super useful when restoring data on a server where rows don't always fall into the same partitions as they did on the original server. When does that even happen? For example, if the partitioning column is of type text and the two systems have different definitions of the collation used to sort the partitioning column. Vibe mismatch, essentially 💅
  • *--lock-wait-timeout=timeout* — do not wait forever to acquire shared table locks at the beginning of the dump. Instead, fail if it's unable to lock a table within the specified timeout. The timeout may be specified in any of the formats accepted by SET statement_timeout. (Allowed formats vary depending on the server version you're dumping from, but an integer number of milliseconds is accepted by all versions — so when in doubt, milliseconds, bestie 🎀)
  • --no-comments — do not dump comments. That's it. That's the whole thing 💀
  • --no-publications — do not dump publications.
  • --no-security-labels — do not dump security labels.
  • --no-subscriptions — do not dump subscriptions.
  • --no-sync — by default, pg_dump will wait for all files to be written safely to disk. This option causes pg_dump to return without waiting, which is faster, but means a subsequent operating system crash can leave the dump corrupt 💀. Generally this option is useful for testing but should not be used when dumping data from a production installation. Like, don't do it. I'm serious.
  • --no-table-access-method — do not output commands to select table access methods. With this option, all objects will be created with whichever table access method is the default during restore.

This option is ignored when emitting an archive (non-text) output file. For the archive formats, you can specify the option when you call pg_restore ✨

  • --no-tablespaces — do not output commands to select tablespaces. With this option, all objects will be created in whichever tablespace is the default during restore.

This option is ignored when emitting an archive (non-text) output file. For the archive formats, you can specify the option when you call pg_restore 💅

  • --no-toast-compression — do not output commands to set TOAST compression methods. With this option, all columns will be restored with the default compression setting.
  • --no-unlogged-table-data — do not dump the contents of unlogged tables and sequences. This option has no effect on whether or not the table and sequence definitions (the schema) get dumped — it only suppresses dumping the table and sequence data. Oh, and data in unlogged tables and sequences is always excluded when dumping from a standby server 👑
  • --on-conflict-do-nothing — adds ON CONFLICT DO NOTHING to INSERT commands. This option is not valid unless --inserts, --column-inserts or --rows-per-insert is also specified 🚨
  • --quote-all-identifiers — forces quoting of all identifiers. Highly recommended when dumping a database from a server whose PostgreSQL major version is different from pg_dump's, or when the output is intended to be loaded into a server of a different major version. By default, pg_dump quotes only identifiers that are reserved words in its own major version — which sometimes causes compatibility issues when dealing with servers of other versions that may have slightly different sets of reserved words 😭. Using --quote-all-identifiers prevents those issues, at the price of a harder-to-read dump script. Trade-offs, bestie 💅
  • *--restrict-key=restrict_key* — uses the provided string as the psql \restrict key in the dump output. This can only be specified for plain-text dumps, i.e., when --format is set to plain or the --format option is omitted. If no restrict key is specified, pg_dump will generate a random one as needed. Keys may contain only alphanumeric characters 🔑

This option is primarily intended for testing purposes and other scenarios that require repeatable output (e.g., comparing dump files). It is not recommended for general use, as a malicious server with advance knowledge of the key may be able to inject arbitrary code that will be executed on the machine that runs psql with the dump output. Yeah. That's a whole thing. Be careful 🫶

  • *--rows-per-insert=nrows* — dumps data as INSERT commands (rather than COPY), and controls the maximum number of rows per INSERT command. The value specified must be a number greater than zero. Any error during restoring will cause only rows that are part of the problematic INSERT to be lost, rather than the entire table contents ✨
  • *--section=sectionname* — only dump the named section. The section name can be pre-data, data, or post-data. This option can be specified more than once to select multiple sections. The default is to dump all sections.

So what's in each? The data section contains actual table data, large-object contents, and sequence values. Post-data items include definitions of indexes, triggers, rules, and constraints other than validated check constraints. Pre-data items include all other data definition items. Obsessed with a clean split 💖

  • --serializable-deferrable — uses a serializable transaction for the dump, to ensure the snapshot used is consistent with later database states; but does it by waiting for a point in the transaction stream at which no anomalies can be present, so there isn't a risk of the dump failing or causing other transactions to roll back with a serialization_failure. See Chapter 13 for more info about transaction isolation and concurrency control 👑

This option is not beneficial for a dump intended only for disaster recovery. It could be useful for a dump used to load a copy of the database for reporting or other read-only load sharing while the original database continues to be updated. Without it, the dump may reflect a state which is not consistent with any serial execution of the transactions eventually committed. For example, if batch processing techniques are used, a batch may show as closed in the dump without all of the items which are in the batch appearing. Not the vibe 😭

This option will make no difference if there are no read-write transactions active when pg_dump is started. If read-write transactions are active, the start of the dump may be delayed for an indeterminate length of time. Once running, performance with or without the switch is the same. Periodt.

  • *--snapshot=snapshotname* — uses the specified synchronized snapshot when making a dump of the database (see Table 9.92 for more details).

This option is useful when you need to synchronize the dump with a logical replication slot (see Chapter 49) or with a concurrent session ✨

In the case of a parallel dump, the snapshot name defined by this option is used rather than taking a new snapshot.

  • --strict-names — requires that each extension (-e/--extension), schema (-n/--schema) and table (-t/--table) qualifier match at least one extension/schema/table in the database to be dumped. Note that if none of the extension/schema/table qualifiers find matches, pg_dump will generate an error even without --strict-names 🚨

This option has no effect on -N/--exclude-schema, -T/--exclude-table, or --exclude-table-data. An exclude pattern failing to match any objects is not considered an error. Excludes just vibe, they don't have to match 💅

  • --use-set-session-authorization — outputs SQL-standard SET SESSION AUTHORIZATION commands instead of ALTER OWNER commands to determine object ownership. This makes the dump more standards-compatible, but depending on the history of the objects in the dump, it might not restore properly 😬. Also, a dump using SET SESSION AUTHORIZATION will certainly require superuser privileges to restore correctly, whereas ALTER OWNER requires lesser privileges.
  • -?, --help — show help about pg_dump command line arguments, and exit. Your little cheat sheet 🎀

The following command-line options control the database connection parameters 🔌 — like, this is the "who am I and where am I going" section, bestie.

  • -d dbname, --dbname=dbname — specifies the name of the database to connect to. This is equivalent to specifying dbname as the first non-option argument on the command line. The dbname can be a connection string — and if it is, connection string parameters will override any conflicting command line options. Sneaky but iconic 💅
  • -h host, --host=host — specifies the host name of the machine on which the server is running. If the value begins with a slash, it is used as the directory for the Unix domain socket 🌸. The default is taken from the PGHOST environment variable, if set, else a Unix domain socket connection is attempted.
  • -p port, --port=port — specifies the TCP port or local Unix domain socket file extension on which the server is listening for connections. Defaults to the PGPORT environment variable, if set, or a compiled-in default.
  • -U username, --username=username — user name to connect as. That's the whole description. Short and sweet 🫶
  • -w, --no-password — never issue a password prompt. If the server requires password authentication and a password is not available by other means such as a .pgpass file, the connection attempt will fail. This option can be useful in batch jobs and scripts where no user is present to enter a password 👑
  • -W, --password — force pg_dump to prompt for a password before connecting to a database.

Okay so -W / --password: this option is never essential, bestie, because pg_dump will automatically prompt for a password if the server demands password authentication. But pg_dump will waste a connection attempt finding out that the server wants a password. In some cases it is worth typing -W to avoid the extra connection attempt. 💅

  • --role=rolename — specifies a role name to be used to create the dump. This option causes pg_dump to issue a SET ROLE rolename command after connecting to the database. It’s useful when the authenticated user (specified by -U) lacks privileges needed by pg_dump, but can switch to a role with the required rights. Some installations have a policy against logging in directly as a superuser, and use of this option allows dumps to be made without violating the policy. 👑

🫧 ENVIRONMENT 🫧

  • PGDATABASE, PGHOST, PGOPTIONS, PGPORT, PGUSER — these are the default connection parameters, no cap. 💖
  • PG_COLOR — specifies whether to use color in diagnostic messages. Possible values are always, auto and never.

This utility, like most other PostgreSQL utilities, also uses the environment variables supported by libpq (see Section 34.15). 🌈

🩺 DIAGNOSTICS 🩺

pg_dump internally executes SELECT statements. If you have problems running pg_dump, make sure you are able to select information from the database using, for example, psql(1). Also, any default connection settings and environment variables used by the libpq front-end library will apply. 🫶

The database activity of pg_dump is normally collected by the cumulative statistics system. If this is undesirable, you can set parameter track_counts to false via PGOPTIONS or the ALTER USER command.

📝 NOTES 📝

If your database cluster has any local additions to the template1 database, be careful to restore the output of pg_dump into a truly empty database; otherwise you are likely to get errors due to duplicate definitions of the added objects. To make an empty database without any local additions, copy from template0 not template1, for example:

CREATE DATABASE foo WITH TEMPLATE template0;

When a data-only dump is chosen and the option --disable-triggers is used, pg_dump emits commands to disable triggers on user tables before inserting the data, and then commands to re-enable them after the data has been inserted.

⚠️ If the restore is stopped in the middle, the system catalogs might be left in the wrong state.

The dump file produced by pg_dump does not contain the statistics used by the optimizer to make query planning decisions. Therefore, it is wise to run ANALYZE after restoring from a dump file to ensure optimal performance; see Section 25.1.3 and Section 25.1.6 for more information.

Because pg_dump is used to transfer data to newer versions of PostgreSQL, the output of pg_dump can be expected to load into PostgreSQL server versions newer than pg_dump's version. pg_dump can also dump from PostgreSQL servers older than its own version. (Currently, servers back to version 9.2 are supported.) However, pg_dump cannot dump from PostgreSQL servers newer than its own major version; it will refuse to even try, rather than risk making an invalid dump. Also, it is not guaranteed that pg_dump's output can be loaded into a server of an older major version — not even if the dump was taken from a server of that version. Loading a dump file into an older server may require manual editing of the dump file to remove syntax not understood by the older server. Use of the --quote-all-identifiers option is recommended in cross-version cases, as it can prevent problems arising from varying reserved-word lists in different PostgreSQL versions. 🧚

When dumping logical replication subscriptions, pg_dump will generate CREATE SUBSCRIPTION commands that use the connect = false option, so that restoring the subscription does not make remote connections for creating a replication slot or for initial table copy. That way, the dump can be restored without requiring network access to the remote servers. It is then up to the user to reactivate the subscriptions in a suitable way. If the involved hosts have changed, the connection information might have to be changed. It might also be appropriate to truncate the target tables before initiating a new full table copy. If users intend to copy initial data during refresh they must create the slot with two_phase = false. After the initial sync, the two_phase option will be automatically enabled by the subscriber if the subscription had been originally created with two_phase = true option. 🦋

It is generally recommended to use the -X (--no-psqlrc) option when restoring a database from a plain-text pg_dump script to ensure a clean restore process and prevent potential conflicts with non-default psql configurations. ✨

🌟 EXAMPLES 🌟

To dump a database called mydb into an SQL-script file:

$ pg_dump mydb > db.sql

To reload such a script into a (freshly created) database named newdb:

$ psql -X -d newdb -f db.sql

To dump a database into a custom-format archive file:

$ pg_dump -Fc mydb > db.dump

To dump a database into a directory-format archive:

$ pg_dump -Fd mydb -f dumpdir

To dump a database into a directory-format archive in parallel with 5 worker jobs:

$ pg_dump -Fd mydb -j 5 -f dumpdir

To reload an archive file into a (freshly created) database named newdb:

$ pg_restore -d newdb db.dump

To reload an archive file into the same database it was dumped from, discarding the current contents of that database:

$ pg_restore -d postgres --clean --create db.dump

To dump a single table named mytab:

$ pg_dump -t mytab mydb > db.sql

To dump all tables whose names start with emp in the detroit schema, except for the table named employee_log:

$ pg_dump -t 'detroit.emp*' -T detroit.employee_log mydb > db.sql

To dump all schemas whose names start with east or west and end in gsm, excluding any schemas whose names contain the word test:

$ pg_dump -n 'east*gsm' -n 'west*gsm' -N '*test*' mydb > db.sql

The same, using regular expression notation to consolidate the switches:

$ pg_dump -n '(east|west)*gsm' -N '*test*' mydb > db.sql

To dump all database objects except for tables whose names begin with ts_:

$ pg_dump -T 'ts_*' mydb > db.sql

To specify an upper-case or mixed-case name in -t and related switches, you need to double-quote the name; else it will be folded to lower case (see Patterns below). But double quotes are special to the shell, so in turn they must be quoted. Thus, to dump a single table with a mixed-case name, you need something like

$ pg_dump -t "\"MixedCaseName\"" mydb > mytab.sql

👀 SEE ALSO 👀

pg_dumpall(1), pg_restore(1), psql(1)

That’s the whole page, bestie — signing off from PostgreSQL 15.19, dated 2026, aka PG_DUMP(1) 💖✨🎀

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