ysql_dumpall

Overview

ysql_dumpall is a utility for writing out ("dumping") all YugabyteDB databases of a cluster into one plain-text, SQL script file. The script file contains SQL statements that can be used as input to ysqlsh to restore the databases. It does this by calling ysql_dump for each database in the YugabyteDB cluster. ysql_dumpall also dumps global objects that are common to all databases, such as database roles. (ysql_dump does not export roles.)

Because ysql_dumpall reads tables from all databases, you will most likely have to connect as a database superuser in order to produce a complete dump. Also, you will need superuser privileges to execute the saved script in order to be allowed to add roles and create databases.

The SQL script will be written to the standard output. Use the -f|--file option or shell operators to redirect it into a file.

ysql_dumpall needs to connect multiple times (once per database) to the YugabyteDB cluster. If you use password authentication, it will ask for a password each time. It is convenient to have a ~/.pgpass file in such cases.

Installation

ysql_dumpall is installed with YugabyteDB and is located in the postgres/bin directory of the YugabyteDB home directory.

Online help

Run ysql_dumpall --help to display the online help.

Syntax

ysql_dumpall [ <connection-option> ... ] [ <content-output-formation-option> ... ]

• connection-option: See Connection options.
• content-output-format-option: See Content and output format options

Content and output format options

The following command line options control the content and format of the output.

-a, --data-only

Dump only the data, not the schema (data definitions).

-c, --clean

Include SQL statements to clean (drop) databases before recreating them. DROP statements for roles are added as well.

-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.)

-f filename, --file=filename

Send output to the specified file. If this is omitted, the standard output is used.

-g, --globals-only

Dump only global objects (roles), no databases.

-o, --oids

Dump object identifiers (OIDs) as part of the data for every table. Use this option if your application references the OID columns in some way (that is, in a foreign key constraint). Otherwise, this option should not be used.

-O, --no-owner

Do not output statements to set ownership of objects to match the original database. By default, ysql_dumpall issues ALTER OWNER or SET SESSION AUTHORIZATION statements to set ownership of created schema elements. These statements will fail when the script is run unless it is started by a superuser (or the same user that owns all of the objects in the script). To make a script that can be restored by any user, but will give that user ownership of all the objects, specify -O|--no-owner.

-r, --roles-only

Dump only roles, no databases.

-s, --schema-only

Dump only the object definitions (schema), not data.

-S username, --superuser=username

Specify the superuser username to use when disabling triggers. This is relevant only if --disable-triggers is used. (Usually, it's better to leave this out, and instead start the resulting script as superuser.)

-v, --verbose

Specifies verbose mode. This causes ysql_dumpall to output start and stop times to the dump file, and progress messages to standard error. It will also enable verbose output in ysql_dump.

--version, -V

Print the ysql_dumpall version and exit.

-x, --no-privileges, --no-acl

Prevent dumping of access privileges (GRANT and REVOKE statements).

--column-inserts, --attribute-inserts

Dump data as INSERT statements with explicit column names (INSERT INTO table (column, ...) VALUES ...). This will make restoration very slow; it is mainly useful for making dumps that can be loaded into non-YugabyteDB databases.

--disable-dollar-quoting

This option disables the use of dollar quoting for function bodies, and forces them to be quoted using SQL standard string syntax.

--disable-triggers

This option is relevant only when creating a data-only dump. It instructs ysql_dumpall to include statements to temporarily disable triggers on the target tables while the data is reloaded. Use this if you have referential integrity checks or other triggers on the tables that you do not want to invoke during data reload.

Presently, the statements emitted for --disable-triggers must be done as superuser. So, you should also specify a superuser name with -S|--superuser, or preferably be careful to start the resulting script as a superuser.

--if-exists

Use conditional statements (that is, add an IF EXISTS clause) to drop databases and other objects. This option is not valid unless -c|--clean is also specified.

--inserts

Dump data as INSERT statements (rather than COPY statements). This will make restoration very slow; it is mainly useful for making dumps that can be loaded into non-YugabyteDB databases. Note that the restore might fail altogether if you have rearranged column order. The --column-inserts option is safer, though even slower.

--load-via-partition-root

When dumping data for a table partition, make the COPY or INSERT statements target the root of the partitioning hierarchy that contains it, rather than the partition itself. This causes the appropriate partition to be re-determined for each row when the data is loaded. This may be useful when reloading data on a server where rows do not always fall into the same partitions as they did on the original server. That could 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.

--lock-wait-timeout=timeout

Do not wait forever to acquire shared table locks at the beginning of the dump. Instead, fail if 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 values vary depending on the server version you are dumping from, but an integer number of milliseconds is accepted by all versions.

--no-comments

Do not dump comments.

--no-publications

Do not dump publications.

--no-role-passwords

Do not dump passwords for roles. When restored, roles will have a null password, and password authentication will always fail until the password is set. As password values aren't needed when this option is specified, the role information is read from the catalog view pg_roles instead of pg_authid. Therefore, this option also helps if access to pg_authid is restricted by some security policy. Note: YugabyteDB uses the pg_roles and pg_authid system tables for PostgreSQL compatibility.

--no-security-labels

Do not dump security labels.

--no-subscriptions

Do not dump subscriptions.

--no-sync

By default, ysql_dumpall waits for all files to be written safely to disk. This option causes ysql_dumpall to return without waiting, which is faster, but means that a subsequent operating system crash can leave the dump corrupt. Generally, this option is helpful for testing but should not be used when dumping data from production installation.

--no-unlogged-table-data

Do not dump the contents of unlogged tables. This option has no effect on whether or not the table definitions (schema) are dumped; it only suppresses dumping the table data.

--quote-all-identifiers

Force quoting of all identifiers. This option is recommended when dumping a database from a server whose YugabyteDB major version is different from the ysql_dumpall version, or when the output is intended to be loaded into a server of a different major version. By default, ysql_dumpall quotes only identifiers that are reserved words in its own major version. This sometimes results in compatibility issues when dealing with servers of other versions that may have slightly different sets of reserved words. Using --quote-all-identifiers prevents such issues, at the price of a harder-to-read dump script.

--use-set-session-authorization

Output SQL-standard SET SESSION AUTHORIZATION statements instead of ALTER OWNER statements to determine object ownership. This makes the dump more standards compatible, but depending on the history of the objects in the dump, might not restore properly.

-?, --help

Show help about ysql_dumpall command line arguments and then exit.

Connection options

The following command line options control the database connection parameters.

-d connstr, --dbname=connstr

Specifies parameters used to connect to the server, as a connection string.

The option is called -d|--dbname for consistency with other client applications, but because ysql_dumpall needs to connect to many databases, the database name in the connection string will be ignored. Use the -l|--database option to specify the name of the database used for the initial connection, which will dump global objects and discover what other databases should be dumped.

-h host, --host host

Specifies the host name of the machine on which the database 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.

-l dbname, --database=database

Specifies the name of the database to connect to for dumping global objects and discovering what other databases should be dumped. If not specified, the yugabyte database will be used, and if that does not exist, template1 will be used.

-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 the compiled-in default.

-U username, --username=username

The username to connect as.

-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 helpful in batch jobs and scripts where no user is present to enter a password.

-W, --password

Force ysql_dumpall to prompt for a password before connecting to a database.

This option is never essential, because ysql_dumpall automatically prompts for a password if the server demands password authentication. However, ysql_dumpall will waste a connection attempt finding out that the server wants a password. In some cases it is worth typing -W|--password to avoid the extra connection attempt.

--role=rolename

Specifies a role name to be used to create the dump. This option causes ysql_dumpall to issue a SET ROLE <rolename> statement after connecting to the database. It is helpful when the authenticated user (specified by -U|--username) lacks privileges needed by ysql_dumpall, 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

The following PostgreSQL environment variables, referenced in some ysql_dumpall and ysql_dump options, are used by YugabyteDB for PostgreSQL compatibility:

• PGHOST
• PGPORT
• PGOPTIONS
• PGUSER
• PGCLIENTENCODING

This utility also uses the environment variables supported by libpq.

Notes

• Because ysql_dumpall calls ysql_dump internally, some diagnostic messages will refer to ysql_dump.
• The -c|--clean option can be helpful even when your intention is to restore the dump script into a fresh cluster. Use of -c|--clean authorizes the script to drop and recreate the built-in yugabyte, postgres, and template1 databases, ensuring that those databases will retain the same properties (for instance, locale and encoding) that they had in the source cluster. Without the option, those databases will retain their existing database-level properties, as well as any pre-existing contents.
• Once restored, it is recommended to run ANALYZE on each database so the optimizer has helpful statistics. You can also run vacuumdb -a -z to analyze all databases.
• The dump script should not be expected to run completely without errors. In particular, because the script will issue CREATE ROLE statements for every role existing in the source cluster, it is certain to get a role already exists error for the bootstrap superuser, unless the destination cluster was initialized with a different bootstrap superuser name. This error is harmless and should be ignored. Use of the -c|--clean option is likely to produce additional harmless error messages about non-existent objects, although you can minimize those by adding --if-exists.

Examples

Dump all databases

$ ./postgres/bin/ysql_dumpall > db.out

To reload databases from this file, you can use:

$ ./bin/ysqlsh -f db.out yugabyte

The database to which you connect is not important because the script file created by ysql_dumpall will contain the appropriate statements to create and connect to the saved databases. An exception is that if you specified -c|--clean, you must connect to the postgres database initially; the script will attempt to drop other databases immediately, and that will fail for the database you are connected to.

See Also

• ysql_dump
• ysqlsh