Columnar temp tables cannot be accessed(#8235).

Fix PR comments.

src/backend/columnar/columnar_metadata.c

@@ -1323,7 +1323,7 @@ GetHighestUsedAddress(Relation rel)
  * In case if relid hasn't been defined yet, we should use RelidByRelfilenumber
  * to get correct relid value.
  *
- * Now it is basically used for temp rels, because since PGXX RelidByRelfilenumber
+ * Now it is basically used for temp rels, because since PG13 RelidByRelfilenumber
  * skip temp relations and we should use alternative ways to get relid value in case
  * of temp objects.
  */

src/backend/columnar/columnar_writer.c

@@ -47,7 +47,7 @@ struct ColumnarWriteState
 	TupleDesc tupleDescriptor;
 	FmgrInfo **comparisonFunctionArray;
 	RelFileLocator relfilelocator;
-	Oid temp_relid;          /* We can't rely on RelidByRelfilenumber for temp tables anymore.*/
+	Oid temp_relid;          /* We can't rely on RelidByRelfilenumber for temp tables since PG18.*/
 
 	MemoryContext stripeWriteContext;
 	MemoryContext perTupleContext;

src/include/columnar/columnar.h

@@ -65,7 +65,7 @@
 #define CITUS_COLUMNAR_INTERNAL_VERSION "11.1-0"
 
 /*
- * We can't rely on RelidByRelfilenumber for temp tables since PGXX, so we can use
+ * We can't rely on RelidByRelfilenumber for temp tables since PG13, so we can use
  * this macro to define relid within relation in case of temp relations. Otherwise
  * RelidByRelfilenumber should be used.
  */