This allows specifying an optional column list when adding a table to
logical replication. The column list may be specified after the table
name, enclosed in parentheses. Columns not included in this list are not
sent to the subscriber, allowing the schema on the subscriber to be a
subset of the publisher schema.
For UPDATE/DELETE publications, the column list needs to cover all
REPLICA IDENTITY columns. For INSERT publications, the column list is
arbitrary and may omit some REPLICA IDENTITY columns. Furthermore, if
the table uses REPLICA IDENTITY FULL, column list is not allowed.
The column list can contain only simple column references. Complex
expressions, function calls etc. are not allowed. This restriction could
be relaxed in the future.
During the initial table synchronization, only columns included in the
column list are copied to the subscriber. If the subscription has
several publications, containing the same table with different column
lists, columns specified in any of the lists will be copied.
This means all columns are replicated if the table has no column list
at all (which is treated as column list with all columns), or when of
the publications is defined as FOR ALL TABLES (possibly IN SCHEMA that
matches the schema of the table).
For partitioned tables, publish_via_partition_root determines whether
the column list for the root or the leaf relation will be used. If the
parameter is 'false' (the default), the list defined for the leaf
relation is used. Otherwise, the column list for the root partition
will be used.
Psql commands \dRp+ and \d <table-name> now display any column lists.
Author: Tomas Vondra, Alvaro Herrera, Rahila Syed
Reviewed-by: Peter Eisentraut, Alvaro Herrera, Vignesh C, Ibrar Ahmed,
Amit Kapila, Hou zj, Peter Smith, Wang wei, Tang, Shi yu
Discussion: https://postgr.es/m/CAH2L28vddB_NFdRVpuyRBJEBWjz4BSyTB=_ektNRH8NJ1jf95g@mail.gmail.com
-- More column list tests for validating column references
CREATE TABLE rf_tbl_abcd_nopk(a int, b int, c int, d int);
CREATE TABLE rf_tbl_abcd_pk(a int, b int, c int, d int, PRIMARY KEY(a,b));
CREATE TABLE rf_tbl_abcd_part_pk (a int PRIMARY KEY, b int) PARTITION by RANGE (a);
CREATE TABLE rf_tbl_abcd_part_pk_1 (b int, a int PRIMARY KEY);
ALTER TABLE rf_tbl_abcd_part_pk ATTACH PARTITION rf_tbl_abcd_part_pk_1 FOR VALUES FROM (1) TO (10);
-- Case 1. REPLICA IDENTITY DEFAULT (means use primary key or nothing)
-- 1a. REPLICA IDENTITY is DEFAULT and table has a PK.
SET client_min_messages = 'ERROR';
CREATE PUBLICATION testpub6 FOR TABLE rf_tbl_abcd_pk (a, b);
RESET client_min_messages;
-- ok - (a,b) coverts all PK cols
UPDATE rf_tbl_abcd_pk SET a = 1;
ALTER PUBLICATION testpub6 SET TABLE rf_tbl_abcd_pk (a, b, c);
-- ok - (a,b,c) coverts all PK cols
UPDATE rf_tbl_abcd_pk SET a = 1;
ALTER PUBLICATION testpub6 SET TABLE rf_tbl_abcd_pk (a);
-- fail - "b" is missing from the column list
UPDATE rf_tbl_abcd_pk SET a = 1;
ERROR: cannot update table "rf_tbl_abcd_pk"
DETAIL: Column list used by the publication does not cover the replica identity.
ALTER PUBLICATION testpub6 SET TABLE rf_tbl_abcd_pk (b);
-- fail - "a" is missing from the column list
UPDATE rf_tbl_abcd_pk SET a = 1;
ERROR: cannot update table "rf_tbl_abcd_pk"
DETAIL: Column list used by the publication does not cover the replica identity.
-- 1b. REPLICA IDENTITY is DEFAULT and table has no PK
ALTER PUBLICATION testpub6 SET TABLE rf_tbl_abcd_nopk (a);
-- ok - there's no replica identity, so any column list works
-- note: it fails anyway, just a bit later because UPDATE requires RI
UPDATE rf_tbl_abcd_nopk SET a = 1;
ERROR: cannot update table "rf_tbl_abcd_nopk" because it does not have a replica identity and publishes updates
HINT: To enable updating the table, set REPLICA IDENTITY using ALTER TABLE.
-- Case 2. REPLICA IDENTITY FULL
ALTER TABLE rf_tbl_abcd_pk REPLICA IDENTITY FULL;
ALTER TABLE rf_tbl_abcd_nopk REPLICA IDENTITY FULL;
ALTER PUBLICATION testpub6 SET TABLE rf_tbl_abcd_pk (c);
-- fail - with REPLICA IDENTITY FULL no column list is allowed
UPDATE rf_tbl_abcd_pk SET a = 1;
ERROR: cannot update table "rf_tbl_abcd_pk"
DETAIL: Column list used by the publication does not cover the replica identity.
ALTER PUBLICATION testpub6 SET TABLE rf_tbl_abcd_nopk (a, b, c, d);
-- fail - with REPLICA IDENTITY FULL no column list is allowed
UPDATE rf_tbl_abcd_nopk SET a = 1;
ERROR: cannot update table "rf_tbl_abcd_nopk"
DETAIL: Column list used by the publication does not cover the replica identity.
-- Case 3. REPLICA IDENTITY NOTHING
ALTER TABLE rf_tbl_abcd_pk REPLICA IDENTITY NOTHING;
ALTER TABLE rf_tbl_abcd_nopk REPLICA IDENTITY NOTHING;
ALTER PUBLICATION testpub6 SET TABLE rf_tbl_abcd_pk (a);
-- ok - REPLICA IDENTITY NOTHING means all column lists are valid
-- it still fails later because without RI we can't replicate updates
UPDATE rf_tbl_abcd_pk SET a = 1;
ERROR: cannot update table "rf_tbl_abcd_pk" because it does not have a replica identity and publishes updates
HINT: To enable updating the table, set REPLICA IDENTITY using ALTER TABLE.
ALTER PUBLICATION testpub6 SET TABLE rf_tbl_abcd_pk (a, b, c, d);
-- ok - REPLICA IDENTITY NOTHING means all column lists are valid
-- it still fails later because without RI we can't replicate updates
UPDATE rf_tbl_abcd_pk SET a = 1;
ERROR: cannot update table "rf_tbl_abcd_pk" because it does not have a replica identity and publishes updates
HINT: To enable updating the table, set REPLICA IDENTITY using ALTER TABLE.
ALTER PUBLICATION testpub6 SET TABLE rf_tbl_abcd_nopk (d);
-- ok - REPLICA IDENTITY NOTHING means all column lists are valid
-- it still fails later because without RI we can't replicate updates
UPDATE rf_tbl_abcd_nopk SET a = 1;
ERROR: cannot update table "rf_tbl_abcd_nopk" because it does not have a replica identity and publishes updates
HINT: To enable updating the table, set REPLICA IDENTITY using ALTER TABLE.
-- Case 4. REPLICA IDENTITY INDEX
ALTER TABLE rf_tbl_abcd_pk ALTER COLUMN c SET NOT NULL;
CREATE UNIQUE INDEX idx_abcd_pk_c ON rf_tbl_abcd_pk(c);
ALTER TABLE rf_tbl_abcd_pk REPLICA IDENTITY USING INDEX idx_abcd_pk_c;
ALTER TABLE rf_tbl_abcd_nopk ALTER COLUMN c SET NOT NULL;
CREATE UNIQUE INDEX idx_abcd_nopk_c ON rf_tbl_abcd_nopk(c);
ALTER TABLE rf_tbl_abcd_nopk REPLICA IDENTITY USING INDEX idx_abcd_nopk_c;
ALTER PUBLICATION testpub6 SET TABLE rf_tbl_abcd_pk (a);
-- fail - column list "a" does not cover the REPLICA IDENTITY INDEX on "c"
UPDATE rf_tbl_abcd_pk SET a = 1;
ERROR: cannot update table "rf_tbl_abcd_pk"
DETAIL: Column list used by the publication does not cover the replica identity.
ALTER PUBLICATION testpub6 SET TABLE rf_tbl_abcd_pk (c);
-- ok - column list "c" does cover the REPLICA IDENTITY INDEX on "c"
UPDATE rf_tbl_abcd_pk SET a = 1;
ALTER PUBLICATION testpub6 SET TABLE rf_tbl_abcd_nopk (a);
-- fail - column list "a" does not cover the REPLICA IDENTITY INDEX on "c"
UPDATE rf_tbl_abcd_nopk SET a = 1;
ERROR: cannot update table "rf_tbl_abcd_nopk"
DETAIL: Column list used by the publication does not cover the replica identity.
ALTER PUBLICATION testpub6 SET TABLE rf_tbl_abcd_nopk (c);
-- ok - column list "c" does cover the REPLICA IDENTITY INDEX on "c"
UPDATE rf_tbl_abcd_nopk SET a = 1;
-- Tests for partitioned table
-- set PUBLISH_VIA_PARTITION_ROOT to false and test column list for partitioned
-- table
ALTER PUBLICATION testpub6 SET (PUBLISH_VIA_PARTITION_ROOT=0);
-- fail - cannot use column list for partitioned table
ALTER PUBLICATION testpub6 SET TABLE rf_tbl_abcd_part_pk (a);
ERROR: cannot use publication column list for relation "rf_tbl_abcd_part_pk"
DETAIL: column list cannot be used for a partitioned table when publish_via_partition_root is false.
-- ok - can use column list for partition
ALTER PUBLICATION testpub6 SET TABLE rf_tbl_abcd_part_pk_1 (a);
-- ok - "a" is a PK col
UPDATE rf_tbl_abcd_part_pk SET a = 1;
-- set PUBLISH_VIA_PARTITION_ROOT to true and test column list for partitioned
-- table
ALTER PUBLICATION testpub6 SET (PUBLISH_VIA_PARTITION_ROOT=1);
-- ok - can use column list for partitioned table
ALTER PUBLICATION testpub6 SET TABLE rf_tbl_abcd_part_pk (a);
-- ok - "a" is a PK col
UPDATE rf_tbl_abcd_part_pk SET a = 1;
-- fail - cannot set PUBLISH_VIA_PARTITION_ROOT to false if any column list is
-- used for partitioned table
ALTER PUBLICATION testpub6 SET (PUBLISH_VIA_PARTITION_ROOT=0);
ERROR: cannot set publish_via_partition_root = false for publication "testpub6"
DETAIL: The publication contains a column list for a partitioned table "rf_tbl_abcd_part_pk" which is not allowed when publish_via_partition_root is false.
-- Now change the root column list to use a column "b"
-- (which is not in the replica identity)
ALTER PUBLICATION testpub6 SET TABLE rf_tbl_abcd_part_pk_1 (b);
-- ok - we don't have column list for partitioned table.
ALTER PUBLICATION testpub6 SET (PUBLISH_VIA_PARTITION_ROOT=0);
Tomas Vondra
3 years ago