CREATE SUBSCRIPTION — define a new subscription
publication_name[, ...] [ WITH (
value] [, ... ] ) ]
CREATE SUBSCRIPTION adds a new subscription for the current database. The subscription name must be distinct from the name of any existing subscription in the database.
The subscription represents a replication connection to the publisher. As such this command does not only add definitions in the local catalogs but also 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.
The name of the new subscription.
The connection string to the publisher. For details see Section 35.1.1.
Names of the publications on the publisher to subscribe to.
value] [, ... ] )
This clause specifies optional parameters for a subscription. The following parameters are supported:
Specifies whether the existing data in the publications that are being subscribed to should be copied once the replication starts. The default is
Specifies whether the command should create the replication slot on the publisher. The default is
Specifies whether the subscription should be actively replicating, or whether it should be just setup but not started yet. The default is
Name of the replication slot to use. The default behavior is to use the name of the subscription for the slot name.
slot_nameis set to
NONE, there will be no replication slot associated with the subscription. This can be used if the replication slot will be created later manually. Such subscriptions must also have both
The value of this parameter overrides the synchronous_commit setting within this subscription's apply worker processes. The default value is
It is safe to use
offfor 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_commitfor the subscriber to
offwhen the subscription is used for synchronous replication might increase the latency for
COMMITon the publisher. In this scenario, it can be advantageous to set
Specifies whether the subscription will request the publisher to send the data in binary format (as opposed to text). The default is
false. Even when this option is enabled, only data types that have binary send and receive functions will be transferred in binary.
When doing cross-version replication, it could happen that the publisher has a binary send function for some data type, but the subscriber lacks a binary receive function for the type. In such a case, data transfer will fail, and the
binaryoption cannot be used.
Specifies whether the
CREATE SUBSCRIPTIONshould connect to the publisher at all. Setting this to
falsewill change default values of
It is not allowed to combine
Since no connection is made when this option is set to
false, the tables are not subscribed, and so after you enable the subscription nothing will be replicated. It is required to run
ALTER SUBSCRIPTION ... REFRESH PUBLICATIONin order for tables to be subscribed.
Specifies whether streaming of in-progress transactions should be enabled for this subscription. By default, all transactions are fully decoded on the publisher, and only then sent to the subscriber as a whole.
See Section 30.7 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. This is an implementation restriction that might be lifted in a future release.
Create a subscription to a remote server that replicates tables in the publications
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);
CREATE SUBSCRIPTION is a Postgres Pro extension.