PAX/toast: aux's TOAST follows heap/AO namespace routing

contrib/pax_storage/src/cpp/catalog/pax_aux_table.cc

@@ -89,6 +89,11 @@ void CPaxCreateMicroPartitionTable(Relation rel) {
   pax_relid = RelationGetRelid(rel);
 
   // 1. create blocks table.
+  //
+  // The aux relation always lives in pg_ext_aux, regardless of the
+  // parent's persistence.  See the persistence selection comment on
+  // the heap_create_with_catalog call below for why TEMP parents'
+  // aux is clamped to PERMANENT rather than passed through.
   snprintf(aux_relname, sizeof(aux_relname), "pg_pax_blocks_%u", pax_relid);
   aux_namespace_id = PG_EXTAUX_NAMESPACE;
   aux_relid = GetNewOidForRelation(pg_class_desc, ClassOidIndexId,
@@ -121,14 +126,26 @@ void CPaxCreateMicroPartitionTable(Relation rel) {
     attr->attnotnull = true;
   }
 
-  // FIXME: temporary table in aux namespace  is not supported yet.
+  /*
+   * Aux inherits the parent's persistence for PERMANENT / UNLOGGED.
+   * TEMP is clamped down to PERMANENT: the aux lives in pg_ext_aux
+   * (NOT in pg_temp_<N>), so a TEMP-persistence row there would
+   * mis-trigger RELATION_IS_OTHER_TEMP — relcache sets
+   * rd_islocaltemp=false because pg_ext_aux is not a temp namespace,
+   * and any reindex_index() path on the aux (or anything that walks
+   * the catalog and stumbles on it) bails with "cannot reindex
+   * temporary tables of other sessions".  Clamping to PERMANENT
+   * avoids that mis-classification; the trade-off is that the aux
+   * of a TEMP PAX table outlives the session (already a known
+   * limitation — see the long-standing FIXME further up the file).
+   */
   relid = heap_create_with_catalog(
       aux_relname, aux_namespace_id, InvalidOid, aux_relid, InvalidOid,
       InvalidOid, rel->rd_rel->relowner, HEAP_TABLE_AM_OID, tupdesc, NIL,
       RELKIND_RELATION,
-      rel->rd_rel->relpersistence == RELPERSISTENCE_UNLOGGED
-          ? RELPERSISTENCE_UNLOGGED
-          : RELPERSISTENCE_PERMANENT,
+      rel->rd_rel->relpersistence == RELPERSISTENCE_TEMP
+          ? RELPERSISTENCE_PERMANENT
+          : rel->rd_rel->relpersistence,
       rel->rd_rel->relisshared, RelationIsMapped(rel), ONCOMMIT_NOOP,
       NULL,                         /* GP Policy */
       (Datum)0, false,              /* use _user_acl */

src/backend/catalog/toasting.c

@@ -167,11 +167,16 @@ create_toast_table(Relation rel, Oid toastOid, Oid toastIndexOid,
 	/*
 	 * Toast tables for regular relations go in pg_toast; those for temp
 	 * relations go into the per-backend temp-toast-table namespace.
+	 *
+	 * Cloudberry used to have a third branch here that routed TOAST
+	 * for relations whose parent namespace was pg_ext_aux back into
+	 * pg_ext_aux too — this was inconsistent with how every other
+	 * Cloudberry / Postgres relation handles toasting.  Treat
+	 * pg_ext_aux parents like any other regular schema; their TOAST
+	 * lands in pg_toast.
 	 */
 	if (isTempOrTempToastNamespace(rel->rd_rel->relnamespace))
 		namespaceid = GetTempToastNamespace();
-	else if (IsExtAuxNamespace(rel->rd_rel->relnamespace))
-		namespaceid = PG_EXTAUX_NAMESPACE;
 	else
 		namespaceid = PG_TOAST_NAMESPACE;