man > CREATE_SUBSCRIPTION(7)

CREATE SUBSCRIPTION(7)             PostgreSQL 16.14 Documentation             CREATE SUBSCRIPTION(7)

NAME
       CREATE_SUBSCRIPTION - define a new subscription

SYNOPSIS
       CREATE SUBSCRIPTION subscription_name
           CONNECTION 'conninfo'
           PUBLICATION publication_name [, ...]
           [ WITH ( subscription_parameter [= value] [, ... ] ) ]

DESCRIPTION
       CREATE SUBSCRIPTION adds a new logical-replication subscription. The user that creates a
       subscription becomes the owner of the subscription. The subscription name must be distinct
       from the name of any existing subscription in the current database.

       A subscription represents a replication connection to the publisher. Hence, in addition to
       adding definitions in the local catalogs, this command normally creates a replication slot on
       the publisher.

       A logical replication worker will be started to replicate data for the new subscription at
       the commit of the transaction where this command is run, unless the subscription is initially
       disabled.

       To be able to create a subscription, you must have the privileges of the the
       pg_create_subscription role, as well as CREATE privileges on the current database.

       Additional information about subscriptions and logical replication as a whole is available at
       Section 31.2 and Chapter 31.

PARAMETERS
       subscription_name
           The name of the new subscription.

       CONNECTION 'conninfo'
           The libpq connection string defining how to connect to the publisher database. For
           details see Section 34.1.1.

       PUBLICATION publication_name [, ...]
           Names of the publications on the publisher to subscribe to.

       WITH ( subscription_parameter [= value] [, ... ] )
           This clause specifies optional parameters for a subscription.

           The following parameters control what happens during subscription creation:

           connect (boolean)
               Specifies whether the CREATE SUBSCRIPTION command should connect to the publisher at
               all. The default is true. Setting this to false will force the values of create_slot,
               enabled and copy_data to false. (You cannot combine setting connect to false with
               setting create_slot, enabled, or copy_data to true.)

               Since no connection is made when this option is false, no tables are subscribed. To
               initiate replication, you must manually create the replication slot, enable the
               subscription, and refresh the subscription. See Section 31.2.3 for examples.

           create_slot (boolean)
               Specifies whether the command should create the replication slot on the publisher.
               The default is true.

               If set to false, you are responsible for creating the publisher's slot in some other
               way. See Section 31.2.3 for examples.

           enabled (boolean)
               Specifies whether the subscription should be actively replicating or whether it
               should just be set up but not started yet. The default is true.

           slot_name (string)
               Name of the publisher's replication slot to use. The default is to use the name of
               the subscription for the slot name.

               Setting slot_name to NONE means there will be no replication slot associated with the
               subscription. Such subscriptions must also have both enabled and create_slot set to
               false. Use this when you will be creating the replication slot later manually. See
               Section 31.2.3 for examples.

           The following parameters control the subscription's replication behavior after it has
           been created:

           binary (boolean)
               Specifies whether the subscription will request the publisher to send the data in
               binary format (as opposed to text). The default is false. Any initial table
               synchronization copy (see copy_data) also uses the same format. Binary format can be
               faster than the text format, but it is less portable across machine architectures and
               PostgreSQL versions. Binary format is very data type specific; for example, it will
               not allow copying from a smallint column to an integer column, even though that would
               work fine in text format. Even when this option is enabled, only data types having
               binary send and receive functions will be transferred in binary. Note that the
               initial synchronization requires all data types to have binary send and receive
               functions, otherwise the synchronization will fail (see CREATE TYPE (CREATE_TYPE(7))
               for more about send/receive functions).

               When doing cross-version replication, it could be that the publisher has a binary
               send function for some data type, but the subscriber lacks a binary receive function
               for that type. In such a case, data transfer will fail, and the binary option cannot
               be used.

               If the publisher is a PostgreSQL version before 16, then any initial table
               synchronization will use text format even if binary = true.

           copy_data (boolean)
               Specifies whether to copy pre-existing data in the publications that are being
               subscribed to when the replication starts. The default is true.

               If the publications contain WHERE clauses, it will affect what data is copied. Refer
               to the Notes for details.

               See Notes for details of how copy_data = true can interact with the origin parameter.

           streaming (enum)
               Specifies whether to enable streaming of in-progress transactions for this
               subscription. The default value is off, meaning all transactions are fully decoded on
               the publisher and only then sent to the subscriber as a whole.

               If set to on, the incoming changes are written to temporary files and then applied
               only after the transaction is committed on the publisher and received by the
               subscriber.

               If set to parallel, incoming changes are directly applied via one of the parallel
               apply workers, if available. If no parallel apply worker is free to handle streaming
               transactions then the changes are written to temporary files and applied after the
               transaction is committed. Note that if an error happens in a parallel apply worker,
               the finish LSN of the remote transaction might not be reported in the server log.

           synchronous_commit (enum)
               The value of this parameter overrides the synchronous_commit setting within this
               subscription's apply worker processes. The default value is off.

               It is safe to use off for logical replication: If the subscriber loses transactions
               because of missing synchronization, the data will be sent again from the publisher.

               A different setting might be appropriate when doing synchronous logical replication.
               The logical replication workers report the positions of writes and flushes to the
               publisher, and when using synchronous replication, the publisher will wait for the
               actual flush. This means that setting synchronous_commit for the subscriber to off
               when the subscription is used for synchronous replication might increase the latency
               for COMMIT on the publisher. In this scenario, it can be advantageous to set
               synchronous_commit to local or higher.

           two_phase (boolean)
               Specifies whether two-phase commit is enabled for this subscription. The default is
               false.

               When two-phase commit is enabled, prepared transactions are sent to the subscriber at
               the time of PREPARE TRANSACTION, and are processed as two-phase transactions on the
               subscriber too. Otherwise, prepared transactions are sent to the subscriber only when
               committed, and are then processed immediately by the subscriber.

               The implementation of two-phase commit requires that replication has successfully
               finished the initial table synchronization phase. So even when two_phase is enabled
               for a subscription, the internal two-phase state remains temporarily “pending” until
               the initialization phase completes. See column subtwophasestate of pg_subscription to
               know the actual two-phase state.

           disable_on_error (boolean)
               Specifies whether the subscription should be automatically disabled if any errors are
               detected by subscription workers during data replication from the publisher. The
               default is false.

           password_required (boolean)
               If set to true, connections to the publisher made as a result of this subscription
               must use password authentication and the password must be specified as a part of the
               connection string. This setting is ignored when the subscription is owned by a
               superuser. The default is true. Only superusers can set this value to false.

           run_as_owner (boolean)
               If true, all replication actions are performed as the subscription owner. If false,
               replication workers will perform actions on each table as the owner of that table.
               The latter configuration is generally much more secure; for details, see
               Section 31.9. The default is false.

           origin (string)
               Specifies whether the subscription will request the publisher to only send changes
               that don't have an origin or send changes regardless of origin. Setting origin to
               none means that the subscription will request the publisher to only send changes that
               don't have an origin. Setting origin to any means that the publisher sends changes
               regardless of their origin. The default is any.

               See Notes for details of how copy_data = true can interact with the origin parameter.

       When specifying a parameter of type boolean, the = value part can be omitted, which is
       equivalent to specifying TRUE.

NOTES
       See Section 31.9 for details on how to configure access control between the subscription and
       the publication instance.

       When creating a replication slot (the default behavior), CREATE SUBSCRIPTION cannot be
       executed inside a transaction block.

       Creating a subscription that connects to the same database cluster (for example, to replicate
       between databases in the same cluster or to replicate within the same database) will only
       succeed if the replication slot is not created as part of the same command. Otherwise, the
       CREATE SUBSCRIPTION call will hang. To make this work, create the replication slot separately
       (using the function pg_create_logical_replication_slot with the plugin name pgoutput) and
       create the subscription using the parameter create_slot = false. See Section 31.2.3 for
       examples. This is an implementation restriction that might be lifted in a future release.

       If any table in the publication has a WHERE clause, rows for which the expression evaluates
       to false or null will not be published. If the subscription has several publications in which
       the same table has been published with different WHERE clauses, a row will be published if
       any of the expressions (referring to that publish operation) are satisfied. In the case of
       different WHERE clauses, if one of the publications has no WHERE clause (referring to that
       publish operation) or the publication is declared as FOR ALL TABLES or FOR TABLES IN SCHEMA,
       rows are always published regardless of the definition of the other expressions. If the
       subscriber is a PostgreSQL version before 15, then any row filtering is ignored during the
       initial data synchronization phase. For this case, the user might want to consider deleting
       any initially copied data that would be incompatible with subsequent filtering. Because
       initial data synchronization does not take into account the publication publish parameter
       when copying existing table data, some rows may be copied that would not be replicated using
       DML. See Section 31.2.2 for examples.

       Subscriptions having several publications in which the same table has been published with
       different column lists are not supported.

       We allow non-existent publications to be specified so that users can add those later. This
       means pg_subscription can have non-existent publications.

       When using a subscription parameter combination of copy_data = true and origin = NONE, the
       initial sync table data is copied directly from the publisher, meaning that knowledge of the
       true origin of that data is not possible. If the publisher also has subscriptions then the
       copied table data might have originated from further upstream. This scenario is detected and
       a WARNING is logged to the user, but the warning is only an indication of a potential
       problem; it is the user's responsibility to make the necessary checks to ensure the copied
       data origins are really as wanted or not.

       To find which tables might potentially include non-local origins (due to other subscriptions
       created on the publisher) try this SQL query:

           # substitute <pub-names> below with your publication name(s) to be queried
           SELECT DISTINCT PT.schemaname, PT.tablename
           FROM pg_publication_tables PT
                JOIN pg_class C ON (C.relname = PT.tablename)
                JOIN pg_namespace N ON (N.nspname = PT.schemaname),
                pg_subscription_rel PS
           WHERE C.relnamespace = N.oid AND
                 (PS.srrelid = C.oid OR
                 C.oid IN (SELECT relid FROM pg_partition_ancestors(PS.srrelid) UNION
                           SELECT relid FROM pg_partition_tree(PS.srrelid))) AND
                 PT.pubname IN (<pub-names>);

EXAMPLES
       Create a subscription to a remote server that replicates tables in the publications
       mypublication and insert_only and starts replicating immediately on commit:

           CREATE SUBSCRIPTION mysub
                    CONNECTION 'host=192.168.1.50 port=5432 user=foo dbname=foodb'
                   PUBLICATION mypublication, insert_only;

       Create a subscription to a remote server that replicates tables in the insert_only
       publication and does not start replicating until enabled at a later time.

           CREATE SUBSCRIPTION mysub
                    CONNECTION 'host=192.168.1.50 port=5432 user=foo dbname=foodb'
                   PUBLICATION insert_only
                          WITH (enabled = false);

COMPATIBILITY
       CREATE SUBSCRIPTION is a PostgreSQL extension.

SEE ALSO
       ALTER SUBSCRIPTION (ALTER_SUBSCRIPTION(7)), DROP SUBSCRIPTION (DROP_SUBSCRIPTION(7)), CREATE
       PUBLICATION (CREATE_PUBLICATION(7)), ALTER PUBLICATION (ALTER_PUBLICATION(7))

PostgreSQL 16.14                                2026                          CREATE SUBSCRIPTION(7)