gs_dumpall

Background

gs_dumpall, provided by MogDB, is used to export all MogDB database information, including data of the default database postgres, user-defined databases, and common global objects of all MogDB databases.

gs_dumpall is executed by OS user omm.

When gs_dumpall is used to export data, other users can still access (read and write) MogDB databases.

gs_dumpall can export complete, consistent data. For example, if gs_dumpall is started to export MogDB database at T1, data of the database at that time point will be exported, and modifications on the database after that time point will not be exported.

The generated columns are not dumped when gs_dumpall is used.

gs_dumpall exports all MogDB databases in two parts:

• gs_dumpall exports all global objects, including information about database users and groups, tablespaces, and attributes (for example, global access permissions).
• gs_dumpall invokes gs_dump to export SQL scripts from each MogDB database, which contain all the SQL statements required to restore databases.

The exported files are both plain-text SQL scripts. Use gsql to execute them to restore MogDB databases.

Precautions

• gs_dumpall is only used for the primary node and does not support exporting data from the standby and cascade standby node.
• Do not modify an exported file or its content. Otherwise, restoration may fail.
• To ensure the data consistency and integrity, gs_dumpall acquires a share lock on a table to be dumped. If another transaction has acquired a share lock on the table, gs_dumpall waits until this lock is released and then locks the table for dumping. If the table cannot be locked within the specified time, the dump fails. You can customize the timeout duration to wait for lock release by specifying the -lock-wait-timeout option.
• During an export, gs_dumpall reads all tables in a database. Therefore, you need to connect to the database as an MogDB administrator to export a complete file. When you use gsql to execute SQL scripts, cluster administrator permissions are also required to add users and user groups, and create databases.

Syntax

gs_dumpall [OPTION]...

Parameter Description

Common parameters

• -f, --filename=FILENAME

  Sends the output to the specified file. If this parameter is omitted, the standard output is generated.

• -v, --verbose

  Specifies the verbose mode. If it is specified, gs_dumpall writes detailed object comments and the number of startups/stops to the dump file, and progress messages to standard error.

• -V, --version

  Prints the gs_dumpall version and exits.

• --lock-wait-timeout=TIMEOUT

  Do not keep waiting to obtain shared table locks at the beginning of the dump. Consider it as failed if you are unable to lock a table within the specified time. The timeout period can be specified in any of the formats accepted by SET statement_timeout.

• -?, --help

  Displays help about gs_dumpall parameters and exits.

Dump parameters:

• -a, --data-only

  Dumps only the data, not the schema (data definition).

• -c, --clean

  Runs SQL statements to delete databases before rebuilding them. Statements for dumping roles and tablespaces are added.

• -g, --globals-only

  Dumps only global objects (roles and tablespaces) but no databases.

• -o, --oids

  Dumps object identifiers (OIDs) as parts of the data in each table. Use this parameter if your application references the OID columns in some way. If the preceding situation does not occur, do not use this parameter.

• -O, --no-owner

  Do not output commands to set ownership of objects to match the original database. By default, gs_dumpall issues the ALTER OWNER or SET SESSION AUTHORIZATION command to set ownership of created schema objects. These statements will fail when the script is running unless it is started by a system administrator (or the same user that owns all of the objects in the script). To make a script that can be stored by any user and give the user ownership of all objects, specify -O.

• -r, --roles-only

  Dumps only roles but not databases or tablespaces.

• -s, --schema-only

  Dumps only the object definition (schema) but not data.

• -S, --sysadmin=NAME

  Name of the system administrator during the dump.

• -t, --tablespaces-only

  Dumps only tablespaces but not databases or roles.

• -x, --no-privileges

  Prevents the dumping of access permissions (grant/revoke commands).

• --column-inserts|--attribute-inserts

  Exports data by running the INSERT command with explicit column names {INSERT INTO table (column, …) VALUES …}. This will cause a slow restoration. However, since this option generates an independent command for each row, an error in reloading a row causes only the loss of the row rather than the entire table content.

• --disable-dollar-quoting

  Disables the use of dollar sign ($) for function bodies, and forces them to be quoted using the SQL standard string syntax.

• --disable-triggers

  Specifies a reserved port for function expansion. This parameter is not recommended.

• --inserts

  Dumps data by the INSERT statement (rather than COPY). This will cause a slow restoration. The restoration may fail if you rearrange the column order. The --column-inserts option is unaffected against column order changes, though even slower.

• --no-publications

  No dump publications are performed.

• --no-security-labels

  Specifies a reserved port for function expansion. This parameter is not recommended.

• --no-subscriptions

  No dump subscriptions are performed.

• --no-tablespaces

  Does not generate output statements to create tablespaces or select tablespaces for objects. All the objects will be created during restoration, no matter which tablespace is selected when using this option.

• --no-unlogged-table-data

  Specifies a reserved port for function expansion. This parameter is not recommended.

• --include-alter-table

  Exports information about deleted columns in the table.

• --quote-all-identifiers

  Forcibly quotes all identifiers. This parameter is useful when you dump a database for migration to a later version, in which additional keywords may be introduced.

• --dont-overwrite-file

  Does not overwrite the current file.

• --use-set-session-authorization

  Specifies that the standard SQL SET SESSION AUTHORIZATION command rather than ALTER OWNER is returned to ensure the object ownership. This makes dumping more standard. However, if a dump file contains objects that have historical problems, restoration may fail. A dump using SET SESSION AUTHORIZATION requires the system administrator permissions, whereas ALTER OWNER requires lower permissions.

• --with-encryption=AES128

  Specifies that dumping data needs to be encrypted using AES128.

• --with-key=KEY

  The AES128 key rules are as follows:

  • Consists of 8 to 16 characters.
  • Contains at least three of the following character types: uppercase characters, lowercase characters, digits, and special characters (limited to ~!@#$%^&*()-_=+\|[{}];:,<.>/?).

• --include-extensions

  Backs up all CREATE EXTENSION statements if the include-extensions parameter is set.

• --include-templatedb

  Includes template databases during the dump.

• --binary-upgrade

  Specifies a reserved port for function expansion. This parameter is not recommended.

• --binary-upgrade-usermap="USER1=USER2"

  Specifies a reserved port for function expansion. This parameter is not recommended.

• --non-lock-table

  This parameter is only used by the OM tool.

• --tablespaces-postfix

  Specifies a reserved port for function expansion. This parameter is not recommended.

• --parallel-jobs

  Specifies the number of concurrent backup processes. The value range is 1-1000.

• --pipeline

  Uses a pipe to transmit the password. This parameter cannot be used on devices.

NOTE:

• The -g/--globals-only and -r/--roles-only parameters do not coexist.
• The -g/--globals-only and -t/--tablespaces-only parameters do not coexist.
• The -r/--roles-only and -t/--tablespaces-only parameters do not coexist.
• The -s/--schema-only and -a/--data-only parameters do not coexist.
• The -r/--roles-only and -a/--data-only parameters do not coexist.
• The -t/--tablespaces-only and -a/--data-only parameters do not coexist.
• The -g/--globals-only and -a/--data-only parameters do not coexist.
• --tablespaces-postfix must be used in conjunction with --binary-upgrade.
• --binary-upgrade-usermap must be used in conjunction with --binary-upgrade.
• --parallel-jobs must be used in conjunction with -f/--file.

Connection parameters:

• -h, --host

  Specifies the host name. If the value begins with a slash (/), it is used as the directory for the UNIX domain socket. The default value is taken from the _PGHOST_ environment variable. If it is not set, a UNIX domain socket connection is attempted.

  This parameter is used only for defining names of the hosts outside MogDB. The names of the hosts inside MogDB must be 127.0.0.1.

  Environment variable: _PGHOST_

• -l, --database

  Specifies the name of the database connected to dump all objects and discover other databases to be dumped. If this parameter is not specified, the postgres database will be used. If the postgres database does not exist, template1 will be used.

• -p, --port

  Specifies the TCP port listened on by the server or the local Unix domain socket file name extension to ensure a correct connection. The default value is the PGPORT environment variable.

  If the thread pool is enabled, you are advised to use pooler port, that is, the listening port number plus 1.

  Environment variable: _PGPORT_

• -U, --username

  Specifies the user name to connect to.

  Environment variable: _PGUSER_

• -w, --no-password

  Never issues a password prompt. The connection attempt fails if the host requires password verification and the password is not provided in other ways. This parameter is useful in batch jobs and scripts in which no user password is required.

• -W, --password

  Specifies the user password for connection. If the host uses the trust authentication policy, the administrator does not need to enter the -W option. If the -W option is not provided and you are not a system administrator, the Dump Restore tool will ask you to enter a password.

• --role

  Specifies a role name to be used for creating the dump. If this option is selected, the SET ROLE command will be issued after the database is connected to gs_dumpall. It is useful when the authenticated user (specified by -U) lacks the permissions required by gs_dumpall. It allows the user to switch to a role with the required permissions. Some installations have a policy against logging in directly as a system administrator. This option allows dumping data without violating the policy.

• --rolepassword

  Specifies the password of the specific role.

Notice

gs_dumpall internally invokes gs_dump. For details about the diagnosis information, see gs_dump.

Once gs_dumpall is restored, run ANALYZE on each database so that the optimizer can provide useful statistics.

gs_dumpall requires all needed tablespace directories to exit before the restoration. Otherwise, database creation will fail if the databases are in non-default locations.

Examples

Use gs_dumpall to export all MogDB databases at a time.

NOTE: gs_dumpall supports only plain-text format export. Therefore, only gsql can be used to restore a file exported using gs_dumpall.

gs_dumpall -f backup/bkp2.sql -p 37300
gs_dump[port='37300'][dbname='postgres'][2018-06-27 09:55:09]: The total objects number is 2371.
gs_dump[port='37300'][dbname='postgres'][2018-06-27 09:55:35]: [100.00%] 2371 objects have been dumped.
gs_dump[port='37300'][dbname='postgres'][2018-06-27 09:55:46]: dump database dbname='postgres' successfully
gs_dump[port='37300'][dbname='postgres'][2018-06-27 09:55:46]: total time: 55567  ms
gs_dumpall[port='37300'][2018-06-27 09:55:46]: dumpall operation successful
gs_dumpall[port='37300'][2018-06-27 09:55:46]: total time: 56088  ms

Helpful Links

gs_dump and gs_restore