diff options
Diffstat (limited to 'src/backend')
| -rw-r--r-- | src/backend/executor/execQual.c | 15 | ||||
| -rw-r--r-- | src/backend/optimizer/util/clauses.c | 12 |
2 files changed, 23 insertions, 4 deletions
diff --git a/src/backend/executor/execQual.c b/src/backend/executor/execQual.c index ebc6a3f1500..ea8850e12cf 100644 --- a/src/backend/executor/execQual.c +++ b/src/backend/executor/execQual.c @@ -3701,6 +3701,21 @@ ExecEvalNullTest(NullTestState *nstate, if (ntest->argisrow && !(*isNull)) { + /* + * The SQL standard defines IS [NOT] NULL for a non-null rowtype + * argument as: + * + * "R IS NULL" is true if every field is the null value. + * + * "R IS NOT NULL" is true if no field is the null value. + * + * This definition is (apparently intentionally) not recursive; so our + * tests on the fields are primitive attisnull tests, not recursive + * checks to see if they are all-nulls or no-nulls rowtypes. + * + * The standard does not consider the possibility of zero-field rows, + * but here we consider them to vacuously satisfy both predicates. + */ HeapTupleHeader tuple; Oid tupType; int32 tupTypmod; diff --git a/src/backend/optimizer/util/clauses.c b/src/backend/optimizer/util/clauses.c index e7bfc38d566..667e682e2d1 100644 --- a/src/backend/optimizer/util/clauses.c +++ b/src/backend/optimizer/util/clauses.c @@ -2970,7 +2970,7 @@ eval_const_expressions_mutator(Node *node, arg = eval_const_expressions_mutator((Node *) ntest->arg, context); - if (arg && IsA(arg, RowExpr)) + if (ntest->argisrow && arg && IsA(arg, RowExpr)) { /* * We break ROW(...) IS [NOT] NULL into separate tests on its @@ -2981,8 +2981,6 @@ eval_const_expressions_mutator(Node *node, List *newargs = NIL; ListCell *l; - Assert(ntest->argisrow); - foreach(l, rarg->args) { Node *relem = (Node *) lfirst(l); @@ -3001,10 +2999,16 @@ eval_const_expressions_mutator(Node *node, return makeBoolConst(false, false); continue; } + + /* + * Else, make a scalar (argisrow == false) NullTest for this + * field. Scalar semantics are required because IS [NOT] NULL + * doesn't recurse; see comments in ExecEvalNullTest(). + */ newntest = makeNode(NullTest); newntest->arg = (Expr *) relem; newntest->nulltesttype = ntest->nulltesttype; - newntest->argisrow = type_is_rowtype(exprType(relem)); + newntest->argisrow = false; newargs = lappend(newargs, newntest); } /* If all the inputs were constants, result is TRUE */ |