Add CheckCitusVersion() calls to columnarAM (#5308)

Considering all code-paths that we might interact with a columnar table,
add `CheckCitusVersion` calls to tableAM callbacks:
- initializing table scan (`columnar_beginscan` & `columnar_index_fetch_begin`)
- setting a new filenode for a relation (storage initializiation or a table rewrite)
- truncating the storage
- inserting tuple (single and multi)

Also add `CheckCitusVersion` call to:
- drop hook (`ColumnarTableDropHook`)
- `alter_columnar_table_set` & `alter_columnar_table_reset` UDFs
(cherry picked from commit f8b1ff7214)

 Conflicts:
	src/backend/columnar/cstore_tableam.c
	src/test/regress/expected/multi_extension.out
	src/test/regress/sql/multi_extension.sql

 Note: Not applying multi_extension.sql/out changes to 10.0 since
       previous Citus version (9.5) already doesn't have columnarAM.

src/backend/columnar/cstore_tableam.c

@@ -160,6 +160,8 @@ columnar_beginscan(Relation relation, Snapshot snapshot,
 				   ParallelTableScanDesc parallel_scan,
 				   uint32 flags)
 {
+	CheckCitusVersion(ERROR);
+
 	int natts = relation->rd_att->natts;
 	Bitmapset *attr_needed = NULL;
 
@@ -419,6 +421,8 @@ static bool
 columnar_tuple_satisfies_snapshot(Relation rel, TupleTableSlot *slot,
 								  Snapshot snapshot)
 {
+	CheckCitusVersion(ERROR);
+
 	return true;
 }
 
@@ -436,6 +440,8 @@ static void
 columnar_tuple_insert(Relation relation, TupleTableSlot *slot, CommandId cid,
 					  int options, BulkInsertState bistate)
 {
+	CheckCitusVersion(ERROR);
+
 	/*
 	 * columnar_init_write_state allocates the write state in a longer
 	 * lasting context, so no need to worry about it.
@@ -481,6 +487,8 @@ static void
 columnar_multi_insert(Relation relation, TupleTableSlot **slots, int ntuples,
 					  CommandId cid, int options, BulkInsertState bistate)
 {
+	CheckCitusVersion(ERROR);
+
 	TableWriteState *writeState = columnar_init_write_state(relation,
 															RelationGetDescr(relation),
 															GetCurrentSubTransactionId());
@@ -552,6 +560,8 @@ columnar_relation_set_new_filenode(Relation rel,
 								   TransactionId *freezeXid,
 								   MultiXactId *minmulti)
 {
+	CheckCitusVersion(ERROR);
+
 	if (persistence != RELPERSISTENCE_PERMANENT)
 	{
 		ereport(ERROR, (errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
@@ -581,6 +591,8 @@ columnar_relation_set_new_filenode(Relation rel,
 static void
 columnar_relation_nontransactional_truncate(Relation rel)
 {
+	CheckCitusVersion(ERROR);
+
 	RelFileNode relfilenode = rel->rd_node;
 
 	NonTransactionDropWriteState(relfilenode.relNode);
@@ -625,6 +637,8 @@ columnar_relation_copy_for_cluster(Relation OldHeap, Relation NewHeap,
 								   double *tups_vacuumed,
 								   double *tups_recently_dead)
 {
+	CheckCitusVersion(ERROR);
+
 	TupleDesc sourceDesc = RelationGetDescr(OldHeap);
 	TupleDesc targetDesc = RelationGetDescr(NewHeap);
 
@@ -677,6 +691,15 @@ static void
 columnar_vacuum_rel(Relation rel, VacuumParams *params,
 					BufferAccessStrategy bstrategy)
 {
+	if (!CheckCitusVersion(WARNING))
+	{
+		/*
+		 * Skip if the extension catalogs are not up-to-date, but avoid
+		 * erroring during auto-vacuum.
+		 */
+		return;
+	}
+
 	int elevel = (params->options & VACOPT_VERBOSE) ? INFO : DEBUG2;
 
 	/* this should have been resolved by vacuum.c until now */
@@ -1006,6 +1029,8 @@ columnar_index_validate_scan(Relation heapRelation,
 static uint64
 columnar_relation_size(Relation rel, ForkNumber forkNumber)
 {
+	CheckCitusVersion(ERROR);
+
 	uint64 nblocks = 0;
 
 	/* Open it at the smgr level if not already done */
@@ -1031,6 +1056,8 @@ columnar_relation_size(Relation rel, ForkNumber forkNumber)
 static bool
 columnar_relation_needs_toast_table(Relation rel)
 {
+	CheckCitusVersion(ERROR);
+
 	return false;
 }
 
@@ -1040,6 +1067,8 @@ columnar_estimate_rel_size(Relation rel, int32 *attr_widths,
 						   BlockNumber *pages, double *tuples,
 						   double *allvisfrac)
 {
+	CheckCitusVersion(ERROR);
+
 	RelationOpenSmgr(rel);
 	*pages = smgrnblocks(rel->rd_smgr, MAIN_FORKNUM);
 	*tuples = ColumnarTableRowCount(rel);
@@ -1218,6 +1247,8 @@ ColumnarTableDropHook(Oid relid)
 
 	if (IsColumnarTableAmTable(relid))
 	{
+		CheckCitusVersion(ERROR);
+
 		/*
 		 * Drop metadata. No need to drop storage here since for
 		 * tableam tables storage is managed by postgres.
@@ -1653,6 +1684,8 @@ PG_FUNCTION_INFO_V1(alter_columnar_table_set);
 Datum
 alter_columnar_table_set(PG_FUNCTION_ARGS)
 {
+	CheckCitusVersion(ERROR);
+
 	Oid relationId = PG_GETARG_OID(0);
 
 	Relation rel = table_open(relationId, AccessExclusiveLock); /* ALTER TABLE LOCK */
@@ -1762,6 +1795,8 @@ PG_FUNCTION_INFO_V1(alter_columnar_table_reset);
 Datum
 alter_columnar_table_reset(PG_FUNCTION_ARGS)
 {
+	CheckCitusVersion(ERROR);
+
 	Oid relationId = PG_GETARG_OID(0);
 
 	Relation rel = table_open(relationId, AccessExclusiveLock); /* ALTER TABLE LOCK */