CREATE PUBLICATION
CREATE PUBLICATION
CREATE PUBLICATION - define a new publication
Synopsis
CREATE PUBLICATIONname
[ FOR ALL TABLES | FORpublication_object
[, ... ] ] [ WITH (publication_parameter
[=value
] [, ... ] ) ] wherepublication_object
is one of: TABLE [ ONLY ]table_name
[ * ] [ (column_name
[, ... ] ) ] [ WHERE (expression
) ] [, ... ] TABLES IN SCHEMA {schema_name
| CURRENT_SCHEMA } [, ... ]
Description
CREATE PUBLICATION
adds a new publication
into the current database. The publication name must be distinct from
the name of any existing publication in the current database.
A publication is essentially a group of tables whose data changes are intended to be replicated through logical replication. See Section 31.1 for details about how publications fit into the logical replication setup.
Parameters
-
name
-
The name of the new publication.
-
FOR TABLE
-
Specifies a list of tables to add to the publication. If
ONLY
is specified before the table name, only that table is added to the publication. IfONLY
is not specified, the table and all its descendant tables (if any) are added. Optionally,*
can be specified after the table name to explicitly indicate that descendant tables are included. This does not apply to a partitioned table, however. The partitions of a partitioned table are always implicitly considered part of the publication, so they are never explicitly added to the publication.If the optional
WHERE
clause is specified, it defines a row filter expression. Rows for which theexpression
evaluates to false or null will not be published. Note that parentheses are required around the expression. It has no effect onTRUNCATE
commands.When a column list is specified, only the named columns are replicated. If no column list is specified, all columns of the table are replicated through this publication, including any columns added later. It has no effect on
TRUNCATE
commands. See Section 31.4 for details about column lists.Only persistent base tables and partitioned tables can be part of a publication. Temporary tables, unlogged tables, foreign tables, materialized views, and regular views cannot be part of a publication.
Specifying a column list when the publication also publishes
FOR TABLES IN SCHEMA
is not supported.When a partitioned table is added to a publication, all of its existing and future partitions are implicitly considered to be part of the publication. So, even operations that are performed directly on a partition are also published via publications that its ancestors are part of.
-
FOR ALL TABLES
-
Marks the publication as one that replicates changes for all tables in the database, including tables created in the future.
-
FOR TABLES IN SCHEMA
-
Marks the publication as one that replicates changes for all tables in the specified list of schemas, including tables created in the future.
Specifying a schema when the publication also publishes a table with a column list is not supported.
Only persistent base tables and partitioned tables present in the schema will be included as part of the publication. Temporary tables, unlogged tables, foreign tables, materialized views, and regular views from the schema will not be part of the publication.
When a partitioned table is published via schema level publication, all of its existing and future partitions are implicitly considered to be part of the publication, regardless of whether they are from the publication schema or not. So, even operations that are performed directly on a partition are also published via publications that its ancestors are part of.
-
WITH (
publication_parameter
[=value
] [, ... ] ) -
This clause specifies optional parameters for a publication. The following parameters are supported:
-
publish
(string
) -
This parameter determines which DML operations will be published by the new publication to the subscribers. The value is comma-separated list of operations. The allowed operations are
insert
,update
,delete
, andtruncate
. The default is to publish all actions, and so the default value for this option is'insert, update, delete, truncate'
.This parameter only affects DML operations. In particular, the initial data synchronization (see Section 31.7.1 ) for logical replication does not take this parameter into account when copying existing table data.
-
publish_via_partition_root
(boolean
) -
This parameter determines whether changes in a partitioned table (or on its partitions) contained in the publication will be published using the identity and schema of the partitioned table rather than that of the individual partitions that are actually changed; the latter is the default. Enabling this allows the changes to be replicated into a non-partitioned table or a partitioned table consisting of a different set of partitions.
This parameter also affects how row filters and column lists are chosen for partitions; see below for details.
If this is enabled,
TRUNCATE
operations performed directly on partitions are not replicated.
-
Notes
If
FOR TABLE
,
FOR ALL TABLES
or
FOR TABLES IN SCHEMA
are not specified, then the
publication starts out with an empty set of tables. That is useful if
tables or schemas are to be added later.
The creation of a publication does not start replication. It only defines a grouping and filtering logic for future subscribers.
To create a publication, the invoking user must have the
CREATE
privilege for the current database.
(Of course, superusers bypass this check.)
To add a table to a publication, the invoking user must have ownership
rights on the table. The
FOR ALL TABLES
and
FOR TABLES IN SCHEMA
clauses require the invoking
user to be a superuser.
The tables added to a publication that publishes
UPDATE
and/or
DELETE
operations must have
REPLICA IDENTITY
defined. Otherwise those operations will be
disallowed on those tables.
Any column list must include the
REPLICA IDENTITY
columns
in order for
UPDATE
or
DELETE
operations to be published. There are no column list restrictions if the
publication publishes only
INSERT
operations.
A row filter expression (i.e., the
WHERE
clause) must contain only
columns that are covered by the
REPLICA IDENTITY
, in
order for
UPDATE
and
DELETE
operations
to be published. For publication of
INSERT
operations,
any column may be used in the
WHERE
expression. The
row filter allows simple expressions that don't have
user-defined functions, user-defined operators, user-defined types,
user-defined collations, non-immutable built-in functions, or references to
system columns.
The row filter on a table becomes redundant if
FOR TABLES IN SCHEMA
is specified and the table
belongs to the referred schema.
For published partitioned tables, the row filter for each
partition is taken from the published partitioned table if the
publication parameter
publish_via_partition_root
is true,
or from the partition itself if it is false (the default).
See
Section 31.3
for details about row
filters.
Similarly, for published partitioned tables, the column list for each
partition is taken from the published partitioned table if the
publication parameter
publish_via_partition_root
is true,
or from the partition itself if it is false.
For an
INSERT ... ON CONFLICT
command, the publication will
publish the operation that actually results from the command. So depending
of the outcome, it may be published as either
INSERT
or
UPDATE
, or it may not be published at all.
ATTACH
ing a table into a partition tree whose root is
published using a publication with
publish_via_partition_root
set to
true
does not result in the table's existing contents
being replicated.
COPY ... FROM
commands are published
as
INSERT
operations.
DDL operations are not published.
The
WHERE
clause expression is executed with the role used
for the replication connection.
Examples
Create a publication that publishes all changes in two tables:
CREATE PUBLICATION mypublication FOR TABLE users, departments;
Create a publication that publishes all changes from active departments:
CREATE PUBLICATION active_departments FOR TABLE departments WHERE (active IS TRUE);
Create a publication that publishes all changes in all tables:
CREATE PUBLICATION alltables FOR ALL TABLES;
Create a publication that only publishes
INSERT
operations in one table:
CREATE PUBLICATION insert_only FOR TABLE mydata WITH (publish = 'insert');
Create a publication that publishes all changes for tables
users
,
departments
and
all changes for all the tables present in the schema
production
:
CREATE PUBLICATION production_publication FOR TABLE users, departments, TABLES IN SCHEMA production;
Create a publication that publishes all changes for all the tables present in
the schemas
marketing
and
sales
:
CREATE PUBLICATION sales_publication FOR TABLES IN SCHEMA marketing, sales;
Create a publication that publishes all changes for table
users
,
but replicates only columns
user_id
and
firstname
:
CREATE PUBLICATION users_filtered FOR TABLE users (user_id, firstname);
Compatibility
CREATE PUBLICATION
is a
PostgreSQL
extension.