diff options
Diffstat (limited to 'src')
| -rw-r--r-- | src/backend/commands/tablecmds.c | 45 |
1 files changed, 38 insertions, 7 deletions
diff --git a/src/backend/commands/tablecmds.c b/src/backend/commands/tablecmds.c index c21a309f04f..eab570a8675 100644 --- a/src/backend/commands/tablecmds.c +++ b/src/backend/commands/tablecmds.c @@ -5681,14 +5681,10 @@ ATSimpleRecursion(List **wqueue, Relation rel, AlterTableUtilityContext *context) { /* - * Propagate to children if desired. Only plain tables, foreign tables - * and partitioned tables have children, so no need to search for other - * relkinds. + * Propagate to children, if desired and if there are (or might be) any + * children. */ - if (recurse && - (rel->rd_rel->relkind == RELKIND_RELATION || - rel->rd_rel->relkind == RELKIND_FOREIGN_TABLE || - rel->rd_rel->relkind == RELKIND_PARTITIONED_TABLE)) + if (recurse && rel->rd_rel->relhassubclass) { Oid relid = RelationGetRelid(rel); ListCell *child; @@ -6699,6 +6695,41 @@ ATPrepSetNotNull(List **wqueue, Relation rel, return; /* + * If the target column is already marked NOT NULL, we can skip recursing + * to children, because their columns should already be marked NOT NULL as + * well. But there's no point in checking here unless the relation has + * some children; else we can just wait till execution to check. (If it + * does have children, however, this can save taking per-child locks + * unnecessarily. This greatly improves concurrency in some parallel + * restore scenarios.) + * + * Unfortunately, we can only apply this optimization to partitioned + * tables, because traditional inheritance doesn't enforce that child + * columns be NOT NULL when their parent is. (That's a bug that should + * get fixed someday.) + */ + if (rel->rd_rel->relhassubclass && + rel->rd_rel->relkind == RELKIND_PARTITIONED_TABLE) + { + HeapTuple tuple; + bool attnotnull; + + tuple = SearchSysCacheAttName(RelationGetRelid(rel), cmd->name); + + /* Might as well throw the error now, if name is bad */ + if (!HeapTupleIsValid(tuple)) + ereport(ERROR, + (errcode(ERRCODE_UNDEFINED_COLUMN), + errmsg("column \"%s\" of relation \"%s\" does not exist", + cmd->name, RelationGetRelationName(rel)))); + + attnotnull = ((Form_pg_attribute) GETSTRUCT(tuple))->attnotnull; + ReleaseSysCache(tuple); + if (attnotnull) + return; + } + + /* * If we have ALTER TABLE ONLY ... SET NOT NULL on a partitioned table, * apply ALTER TABLE ... CHECK NOT NULL to every child. Otherwise, use * normal recursion logic. |