Thread

Re: CREATE TABLE LIKE INCLUDING TRIGGERS

Zsolt Parragi <zsolt.parragi@percona.com> — 2026-05-27T22:53:13Z

Hello!

Sorry for the late reply, somehow I missed the previous updates.

I found one more problematic scenario, I think the patch should ignore
INSTEAD OF triggers:

CREATE TABLE base (id int, val text);
CREATE VIEW v_instead AS SELECT id, val FROM base;
CREATE FUNCTION v_instead_ins() RETURNS trigger LANGUAGE plpgsql AS $$
BEGIN
  INSERT INTO base VALUES (NEW.id, NEW.val);
  RETURN NEW;
END;
$$;
CREATE TRIGGER v_instead_trg
  INSTEAD OF INSERT ON v_instead
  FOR EACH ROW EXECUTE FUNCTION v_instead_ins();
-- currently fails
-- ERROR:  "t_all" is a table
-- DETAIL:  Tables cannot have INSTEAD OF triggers.
CREATE TABLE t_all (LIKE v_instead INCLUDING ALL);

And also, either I don't understand something here, or the diff can be
simplified a bit:

-		/* Transform expression.  Copy to be sure we don't modify original */
-		whenClause = transformWhereClause(pstate,
-										  copyObject(stmt->whenClause),
-										  EXPR_KIND_TRIGGER_WHEN,
-										  "WHEN");
-		/* we have to fix its collations too */
-		assign_expr_collations(pstate, whenClause);
+		if (stmt->transformed)
+			whenClause = stmt->whenClause;
+		else
+		{
+			/* Transform expression.  Copy to be sure we don't modify original */
+			whenClause = transformWhereClause(pstate,
+											  copyObject(stmt->whenClause),
+											  EXPR_KIND_TRIGGER_WHEN,
+											  "WHEN");
+
+			/* we have to fix its collations too */
+			assign_expr_collations(pstate, whenClause);
+
+			stmt->transformed = true;
+		}


Do we need the last assignment in this diff? It sets
stmt->transformed, but we don't actually transform the statement, we
create a copy. The flag also doesn't seem to be used after that.
Everything seems to work fine if I remove this assignment, and we
don't need the const related function signature changes without it.