Remove pg_replication_origin's TOAST table.

A few places that access this catalog don't set up an active
snapshot before potentially accessing its TOAST table.  However,
roname (the replication origin name) is the only varlena column, so
this is only a problem if the name requires out-of-line storage.
This commit removes its TOAST table to avoid needing to set up a
snapshot.  It also places a limit on replication origin names so
that attempts to set long names will fail with a more user-friendly
error.  Those chosen limit of 512 bytes should be sufficient to
avoid "row is too big" errors independent of BLCKSZ, but it should
also be lenient enough for all reasonable use-cases.

Bumps catversion.

Reviewed-by: Michael Paquier <michael@paquier.xyz>
Reviewed-by: Amit Kapila <amit.kapila16@gmail.com>
Reviewed-by: Euler Taveira <euler@eulerto.com>
Reviewed-by: Nisha Moond <nisha.moond412@gmail.com>
Reviewed-by: Tom Lane <tgl@sss.pgh.pa.us>
Discussion: https://postgr.es/m/ZvMSUPOqUU-VNADN%40nathan

diff --git a/doc/src/sgml/func.sgml b/doc/src/sgml/func.sgml
index bb6e5ab9ff76ebe7aea9056098513b30aadfae69..27ec46105f49eeb6dcdb390536d73d84cc0dc45c 100644 (file)
--- a/doc/src/sgml/func.sgml
+++ b/doc/src/sgml/func.sgml
@@ -29940,6 +29940,7 @@ postgres=# SELECT '0/0'::pg_lsn + pd.segment_number * ps.setting::int + :offset
        <para>
         Creates a replication origin with the given external
         name, and returns the internal ID assigned to it.
+        The name must be no longer than 512 bytes.
        </para></entry>
       </row>
 

diff --git a/src/backend/catalog/catalog.c b/src/backend/catalog/catalog.c
index 60000bd0bc769ccb76036e7b9e5f8027e7bf5fec..59caae8f1bc232a84a5ed4858e750bfa65487ecf 100644 (file)
--- a/src/backend/catalog/catalog.c
+++ b/src/backend/catalog/catalog.c
@@ -346,8 +346,6 @@ IsSharedRelation(Oid relationId)
                relationId == PgDbRoleSettingToastIndex ||
                relationId == PgParameterAclToastTable ||
                relationId == PgParameterAclToastIndex ||
-               relationId == PgReplicationOriginToastTable ||
-               relationId == PgReplicationOriginToastIndex ||
                relationId == PgShdescriptionToastTable ||
                relationId == PgShdescriptionToastIndex ||
                relationId == PgShseclabelToastTable ||

diff --git a/src/backend/replication/logical/origin.c b/src/backend/replication/logical/origin.c
index 6583dd497da2170ffe783f759f1e4bb3591508b8..a17bacf88e7f3d6e508749fc8eee93da555b73bc 100644 (file)
--- a/src/backend/replication/logical/origin.c
+++ b/src/backend/replication/logical/origin.c
@@ -264,6 +264,18 @@ replorigin_create(const char *roname)
        SysScanDesc scan;
        ScanKeyData key;
 
+       /*
+        * To avoid needing a TOAST table for pg_replication_origin, we limit
+        * replication origin names to 512 bytes.  This should be more than enough
+        * for all practical use.
+        */
+       if (strlen(roname) > MAX_RONAME_LEN)
+               ereport(ERROR,
+                               (errcode(ERRCODE_PROGRAM_LIMIT_EXCEEDED),
+                                errmsg("replication origin name is too long"),
+                                errdetail("Replication origin names must be no longer than %d bytes.",
+                                                  MAX_RONAME_LEN)));
+
        roname_d = CStringGetTextDatum(roname);
 
        Assert(IsTransactionState());
@@ -287,6 +299,17 @@ replorigin_create(const char *roname)
 
        rel = table_open(ReplicationOriginRelationId, ExclusiveLock);
 
+       /*
+        * We want to be able to access pg_replication_origin without setting up a
+        * snapshot.  To make that safe, it needs to not have a TOAST table, since
+        * TOASTed data cannot be fetched without a snapshot.  As of this writing,
+        * its only varlena column is roname, which we limit to 512 bytes to avoid
+        * needing out-of-line storage.  If you add a TOAST table to this catalog,
+        * be sure to set up a snapshot everywhere it might be needed.  For more
+        * information, see https://postgr.es/m/ZvMSUPOqUU-VNADN%40nathan.
+        */
+       Assert(!OidIsValid(rel->rd_rel->reltoastrelid));
+
        for (roident = InvalidOid + 1; roident < PG_UINT16_MAX; roident++)
        {
                bool            nulls[Natts_pg_replication_origin];

diff --git a/src/include/catalog/catversion.h b/src/include/catalog/catversion.h
index 3cb695d233cdc80e528fda043bc50e1368fb6cc2..82988d244339049c4091c494d2f53e135a305074 100644 (file)
--- a/src/include/catalog/catversion.h
+++ b/src/include/catalog/catversion.h
@@ -57,6 +57,6 @@
  */
 
 /*                                                     yyyymmddN */
-#define CATALOG_VERSION_NO     202504091
+#define CATALOG_VERSION_NO     202505071
 
 #endif

diff --git a/src/include/catalog/pg_replication_origin.h b/src/include/catalog/pg_replication_origin.h
index deb43065fe9929281150ada58b923100e6c0e32f..7ade8bbda3964cb97600e034c711f3c5eacd8111 100644 (file)
--- a/src/include/catalog/pg_replication_origin.h
+++ b/src/include/catalog/pg_replication_origin.h
@@ -54,8 +54,6 @@ CATALOG(pg_replication_origin,6000,ReplicationOriginRelationId) BKI_SHARED_RELAT
 
 typedef FormData_pg_replication_origin *Form_pg_replication_origin;
 
-DECLARE_TOAST_WITH_MACRO(pg_replication_origin, 4181, 4182, PgReplicationOriginToastTable, PgReplicationOriginToastIndex);
-
 DECLARE_UNIQUE_INDEX_PKEY(pg_replication_origin_roiident_index, 6001, ReplicationOriginIdentIndex, pg_replication_origin, btree(roident oid_ops));
 DECLARE_UNIQUE_INDEX(pg_replication_origin_roname_index, 6002, ReplicationOriginNameIndex, pg_replication_origin, btree(roname text_ops));
 

diff --git a/src/include/replication/origin.h b/src/include/replication/origin.h
index 9cb2248fa9f30b5c076abc3dd13a515d33f7f0ed..2a73f6aa49296371c772539f6ed427197a2da413 100644 (file)
--- a/src/include/replication/origin.h
+++ b/src/include/replication/origin.h
@@ -33,6 +33,13 @@ typedef struct xl_replorigin_drop
 #define InvalidRepOriginId 0
 #define DoNotReplicateId PG_UINT16_MAX
 
+/*
+ * To avoid needing a TOAST table for pg_replication_origin, we limit
+ * replication origin names to 512 bytes.  This should be more than enough for
+ * all practical use.
+ */
+#define MAX_RONAME_LEN 512
+
 extern PGDLLIMPORT RepOriginId replorigin_session_origin;
 extern PGDLLIMPORT XLogRecPtr replorigin_session_origin_lsn;
 extern PGDLLIMPORT TimestampTz replorigin_session_origin_timestamp;

diff --git a/src/test/regress/expected/misc_functions.out b/src/test/regress/expected/misc_functions.out
index d3f5d16a6725dade11b0dc6cf9403d15fb620ee9..cc517ed5e90078efbab4f5e364108c290756a529 100644 (file)
--- a/src/test/regress/expected/misc_functions.out
+++ b/src/test/regress/expected/misc_functions.out
@@ -914,3 +914,7 @@ SELECT test_relpath();
  
 (1 row)
 
+-- pg_replication_origin.roname limit
+SELECT pg_replication_origin_create('regress_' || repeat('a', 505));
+ERROR:  replication origin name is too long
+DETAIL:  Replication origin names must be no longer than 512 bytes.

diff --git a/src/test/regress/expected/misc_sanity.out b/src/test/regress/expected/misc_sanity.out
index b032a3f4761dc8f81ee2f4b9799c4509cb55301c..4ffc45a80187ec4d1f84fdec412da983ea396c2f 100644 (file)
--- a/src/test/regress/expected/misc_sanity.out
+++ b/src/test/regress/expected/misc_sanity.out
@@ -42,6 +42,11 @@ WHERE refclassid = 0 OR refobjid = 0 OR
 -- as user data by pg_upgrade, which would cause failures.
 -- 3. pg_authid, since its toast table cannot be accessed when it would be
 -- needed, i.e., during authentication before we've selected a database.
+-- 4. pg_replication_origin, since we want to be able to access that catalog
+-- without setting up a snapshot.  To make that safe, it needs to not have a
+-- toast table, since toasted data cannot be fetched without a snapshot.  As of
+-- this writing, its only varlena column is roname, which we limit to 512 bytes
+-- to avoid needing out-of-line storage.
 SELECT relname, attname, atttypid::regtype
 FROM pg_class c JOIN pg_attribute a ON c.oid = attrelid
 WHERE c.oid < 16384 AND
@@ -61,7 +66,8 @@ ORDER BY 1, 2;
  pg_class                | relpartbound  | pg_node_tree
  pg_largeobject          | data          | bytea
  pg_largeobject_metadata | lomacl        | aclitem[]
-(10 rows)
+ pg_replication_origin   | roname        | text
+(11 rows)
 
 -- system catalogs without primary keys
 --

diff --git a/src/test/regress/sql/misc_functions.sql b/src/test/regress/sql/misc_functions.sql
index aaebb298330b8520d448ae6afa14179abeb4ca16..5f9c77512d160c30bd112f3b681a9207a73cc1d6 100644 (file)
--- a/src/test/regress/sql/misc_functions.sql
+++ b/src/test/regress/sql/misc_functions.sql
@@ -411,3 +411,6 @@ CREATE FUNCTION test_relpath()
     AS :'regresslib'
     LANGUAGE C;
 SELECT test_relpath();
+
+-- pg_replication_origin.roname limit
+SELECT pg_replication_origin_create('regress_' || repeat('a', 505));

diff --git a/src/test/regress/sql/misc_sanity.sql b/src/test/regress/sql/misc_sanity.sql
index 135793871b4d4ff75215d7a797c9683fd1da3e12..e861614ea7184e7b833e6ff4ed54f84c7b875c05 100644 (file)
--- a/src/test/regress/sql/misc_sanity.sql
+++ b/src/test/regress/sql/misc_sanity.sql
@@ -45,6 +45,11 @@ WHERE refclassid = 0 OR refobjid = 0 OR
 -- as user data by pg_upgrade, which would cause failures.
 -- 3. pg_authid, since its toast table cannot be accessed when it would be
 -- needed, i.e., during authentication before we've selected a database.
+-- 4. pg_replication_origin, since we want to be able to access that catalog
+-- without setting up a snapshot.  To make that safe, it needs to not have a
+-- toast table, since toasted data cannot be fetched without a snapshot.  As of
+-- this writing, its only varlena column is roname, which we limit to 512 bytes
+-- to avoid needing out-of-line storage.
 
 SELECT relname, attname, atttypid::regtype
 FROM pg_class c JOIN pg_attribute a ON c.oid = attrelid