From 7f2581395567b76efd85975d2133ee2c484f18ff Mon Sep 17 00:00:00 2001 From: Roberto Mello Date: Tue, 24 Mar 2026 19:20:10 -0600 Subject: [PATCH v1] Fix pg_publication_tables to return NULL attnames for all-column publications Previously pg_get_publication_tables() synthesized a column list even when no explicit column list was specified in the publication. This made it impossible for consumers of pg_publication_tables to distinguish between "all columns are published" (new columns will automatically be replicated) and an explicit column list (only listed columns are replicated). Worse, the subscriber-side workaround in fetch_remote_table_info() compared array_length(gpt.attrs, 1) against pg_class.relnatts to detect the "all columns" case, but relnatts includes dropped columns while the synthesized list excluded them, so tables with dropped columns were misidentified as having an explicit column list. Fix by simply leaving attrs as NULL when no column list was specified (prattrs is NULL) in the publication catalog. This is consistent with how prattrs itself is stored and removes the need for the relnatts heuristic in tablesync.c. The real replication column filtering (which must account for dropped columns, generated columns, and pub->pubgencols_type) is performed downstream in pgoutput.c by pub_form_cols_map() and check_and_fetch_column_list(), both of which are unchanged by this patch. --- doc/src/sgml/system-views.sgml | 9 ++-- src/backend/catalog/pg_publication.c | 52 ++++--------------- src/backend/replication/logical/tablesync.c | 9 ++-- src/test/regress/expected/publication.out | 57 ++++++++++++++++++--- src/test/regress/sql/publication.sql | 34 ++++++++++++ 5 files changed, 102 insertions(+), 59 deletions(-) diff --git a/doc/src/sgml/system-views.sgml b/doc/src/sgml/system-views.sgml index 9ee1a2bfc6a..6c926860e41 100644 --- a/doc/src/sgml/system-views.sgml +++ b/doc/src/sgml/system-views.sgml @@ -2712,9 +2712,12 @@ SELECT * FROM pg_locks pl LEFT JOIN pg_prepared_xacts ppx (references pg_attribute.attname) - Names of table columns included in the publication. This contains all - the columns of the table when the user didn't specify the column list - for the table. + Names of the table columns included in the publication, or NULL if + no explicit column list was specified for the table. When NULL, all + current and future columns of the table are published; new columns + added to the table will automatically be replicated. When non-NULL, + only the listed columns are replicated, and newly added columns will + not appear until the publication is explicitly altered. diff --git a/src/backend/catalog/pg_publication.c b/src/backend/catalog/pg_publication.c index c92ff3f51c3..a2fa4906f08 100644 --- a/src/backend/catalog/pg_publication.c +++ b/src/backend/catalog/pg_publication.c @@ -1439,49 +1439,15 @@ pg_get_publication_tables(PG_FUNCTION_ARGS) nulls[3] = true; } - /* Show all columns when the column list is not specified. */ - if (nulls[2]) - { - Relation rel = table_open(relid, AccessShareLock); - int nattnums = 0; - int16 *attnums; - TupleDesc desc = RelationGetDescr(rel); - int i; - - attnums = palloc_array(int16, desc->natts); - - for (i = 0; i < desc->natts; i++) - { - Form_pg_attribute att = TupleDescAttr(desc, i); - - if (att->attisdropped) - continue; - - if (att->attgenerated) - { - /* We only support replication of STORED generated cols. */ - if (att->attgenerated != ATTRIBUTE_GENERATED_STORED) - continue; - - /* - * User hasn't requested to replicate STORED generated - * cols. - */ - if (pub->pubgencols_type != PUBLISH_GENCOLS_STORED) - continue; - } - - attnums[nattnums++] = att->attnum; - } - - if (nattnums > 0) - { - values[2] = PointerGetDatum(buildint2vector(attnums, nattnums)); - nulls[2] = false; - } - - table_close(rel, AccessShareLock); - } + /* + * When no column list is specified (prattrs is NULL), we leave + * attrs as NULL rather than synthesizing a list of all current + * columns. This allows consumers of pg_publication_tables to + * distinguish between "all columns are published" (attrs IS + * NULL - new columns will automatically be replicated) and an + * explicit column list (attrs IS NOT NULL - only listed columns + * are replicated). + */ rettuple = heap_form_tuple(funcctx->tuple_desc, values, nulls); diff --git a/src/backend/replication/logical/tablesync.c b/src/backend/replication/logical/tablesync.c index f49a4852ecb..5f6d892e595 100644 --- a/src/backend/replication/logical/tablesync.c +++ b/src/backend/replication/logical/tablesync.c @@ -799,13 +799,10 @@ fetch_remote_table_info(char *nspname, char *relname, LogicalRepRelation *lrel, */ resetStringInfo(&cmd); appendStringInfo(&cmd, - "SELECT DISTINCT" - " (CASE WHEN (array_length(gpt.attrs, 1) = c.relnatts)" - " THEN NULL ELSE gpt.attrs END)" + "SELECT DISTINCT gpt.attrs" " FROM pg_publication p," - " LATERAL pg_get_publication_tables(p.pubname) gpt," - " pg_class c" - " WHERE gpt.relid = %u AND c.oid = gpt.relid" + " LATERAL pg_get_publication_tables(p.pubname) gpt" + " WHERE gpt.relid = %u" " AND p.pubname IN ( %s )", lrel->remoteid, pub_names->data); diff --git a/src/test/regress/expected/publication.out b/src/test/regress/expected/publication.out index a220f48b285..011c6026816 100644 --- a/src/test/regress/expected/publication.out +++ b/src/test/regress/expected/publication.out @@ -2072,7 +2072,7 @@ CREATE PUBLICATION pub FOR TABLES IN SCHEMA sch2 WITH (PUBLISH_VIA_PARTITION_ROO SELECT * FROM pg_publication_tables; pubname | schemaname | tablename | attnames | rowfilter ---------+------------+------------+----------+----------- - pub | sch2 | tbl1_part1 | {a} | + pub | sch2 | tbl1_part1 | | (1 row) DROP PUBLICATION pub; @@ -2081,7 +2081,7 @@ CREATE PUBLICATION pub FOR TABLE sch2.tbl1_part1 WITH (PUBLISH_VIA_PARTITION_ROO SELECT * FROM pg_publication_tables; pubname | schemaname | tablename | attnames | rowfilter ---------+------------+------------+----------+----------- - pub | sch2 | tbl1_part1 | {a} | + pub | sch2 | tbl1_part1 | | (1 row) -- Table publication that includes both the parent table and the child table @@ -2089,7 +2089,7 @@ ALTER PUBLICATION pub ADD TABLE sch1.tbl1; SELECT * FROM pg_publication_tables; pubname | schemaname | tablename | attnames | rowfilter ---------+------------+-----------+----------+----------- - pub | sch1 | tbl1 | {a} | + pub | sch1 | tbl1 | | (1 row) DROP PUBLICATION pub; @@ -2098,7 +2098,7 @@ CREATE PUBLICATION pub FOR TABLES IN SCHEMA sch2 WITH (PUBLISH_VIA_PARTITION_ROO SELECT * FROM pg_publication_tables; pubname | schemaname | tablename | attnames | rowfilter ---------+------------+------------+----------+----------- - pub | sch2 | tbl1_part1 | {a} | + pub | sch2 | tbl1_part1 | | (1 row) DROP PUBLICATION pub; @@ -2107,7 +2107,7 @@ CREATE PUBLICATION pub FOR TABLE sch2.tbl1_part1 WITH (PUBLISH_VIA_PARTITION_ROO SELECT * FROM pg_publication_tables; pubname | schemaname | tablename | attnames | rowfilter ---------+------------+------------+----------+----------- - pub | sch2 | tbl1_part1 | {a} | + pub | sch2 | tbl1_part1 | | (1 row) -- Table publication that includes both the parent table and the child table @@ -2115,7 +2115,7 @@ ALTER PUBLICATION pub ADD TABLE sch1.tbl1; SELECT * FROM pg_publication_tables; pubname | schemaname | tablename | attnames | rowfilter ---------+------------+------------+----------+----------- - pub | sch2 | tbl1_part1 | {a} | + pub | sch2 | tbl1_part1 | | (1 row) DROP PUBLICATION pub; @@ -2130,7 +2130,7 @@ CREATE PUBLICATION pub FOR TABLES IN SCHEMA sch1 WITH (PUBLISH_VIA_PARTITION_ROO SELECT * FROM pg_publication_tables; pubname | schemaname | tablename | attnames | rowfilter ---------+------------+-----------+----------+----------- - pub | sch1 | tbl1 | {a} | + pub | sch1 | tbl1 | | (1 row) RESET client_min_messages; @@ -2139,6 +2139,49 @@ DROP TABLE sch1.tbl1; DROP SCHEMA sch1 cascade; DROP SCHEMA sch2 cascade; -- ====================================================== +-- Test that pg_publication_tables distinguishes between tables with +-- an explicit column list and tables without one (attnames should be +-- NULL when no column list was specified). +CREATE TABLE pub_col_test (id int, name text, status text); +CREATE PUBLICATION pub_nocols FOR TABLE pub_col_test; +CREATE PUBLICATION pub_cols FOR TABLE pub_col_test (id, name); +-- Without column list: attnames should be NULL +SELECT pubname, attnames IS NULL AS all_columns FROM pg_publication_tables + WHERE tablename = 'pub_col_test' ORDER BY pubname; + pubname | all_columns +------------+------------- + pub_cols | f + pub_nocols | t +(2 rows) + +-- With column list: attnames should list specific columns +SELECT pubname, attnames FROM pg_publication_tables + WHERE tablename = 'pub_col_test' AND attnames IS NOT NULL ORDER BY pubname; + pubname | attnames +----------+----------- + pub_cols | {id,name} +(1 row) + +DROP PUBLICATION pub_nocols; +DROP PUBLICATION pub_cols; +DROP TABLE pub_col_test; +-- Test that a table with a dropped column still shows attnames as NULL +-- when no explicit column list was specified. The old implementation +-- compared the synthesized column count against relnatts, but relnatts +-- includes dropped columns, so the heuristic was wrong for this case. +CREATE TABLE pub_dropped_test (id int, dropped_col text, name text); +ALTER TABLE pub_dropped_test DROP COLUMN dropped_col; +CREATE PUBLICATION pub_dropped FOR TABLE pub_dropped_test; +SELECT pubname, attnames IS NULL AS all_columns FROM pg_publication_tables + WHERE tablename = 'pub_dropped_test'; + pubname | all_columns +-------------+------------- + pub_dropped | t +(1 row) + +DROP PUBLICATION pub_dropped; +DROP TABLE pub_dropped_test; +-- ====================================================== -- Test the 'publish_generated_columns' parameter with the following values: -- 'stored', 'none'. SET client_min_messages = 'ERROR'; diff --git a/src/test/regress/sql/publication.sql b/src/test/regress/sql/publication.sql index 22e0a30b5c7..0f3c443a180 100644 --- a/src/test/regress/sql/publication.sql +++ b/src/test/regress/sql/publication.sql @@ -1327,6 +1327,40 @@ DROP SCHEMA sch1 cascade; DROP SCHEMA sch2 cascade; -- ====================================================== +-- Test that pg_publication_tables distinguishes between tables with +-- an explicit column list and tables without one (attnames should be +-- NULL when no column list was specified). +CREATE TABLE pub_col_test (id int, name text, status text); +CREATE PUBLICATION pub_nocols FOR TABLE pub_col_test; +CREATE PUBLICATION pub_cols FOR TABLE pub_col_test (id, name); + +-- Without column list: attnames should be NULL +SELECT pubname, attnames IS NULL AS all_columns FROM pg_publication_tables + WHERE tablename = 'pub_col_test' ORDER BY pubname; + +-- With column list: attnames should list specific columns +SELECT pubname, attnames FROM pg_publication_tables + WHERE tablename = 'pub_col_test' AND attnames IS NOT NULL ORDER BY pubname; + +DROP PUBLICATION pub_nocols; +DROP PUBLICATION pub_cols; +DROP TABLE pub_col_test; + +-- Test that a table with a dropped column still shows attnames as NULL +-- when no explicit column list was specified. The old implementation +-- compared the synthesized column count against relnatts, but relnatts +-- includes dropped columns, so the heuristic was wrong for this case. +CREATE TABLE pub_dropped_test (id int, dropped_col text, name text); +ALTER TABLE pub_dropped_test DROP COLUMN dropped_col; +CREATE PUBLICATION pub_dropped FOR TABLE pub_dropped_test; + +SELECT pubname, attnames IS NULL AS all_columns FROM pg_publication_tables + WHERE tablename = 'pub_dropped_test'; + +DROP PUBLICATION pub_dropped; +DROP TABLE pub_dropped_test; +-- ====================================================== + -- Test the 'publish_generated_columns' parameter with the following values: -- 'stored', 'none'. SET client_min_messages = 'ERROR'; base-commit: 7baa39c468fa1d703d50cd697e9dd05f6831ae38 -- 2.50.1 (Apple Git-155)