150 lines
4.5 KiB
SQL
150 lines
4.5 KiB
SQL
--
|
|
-- Tests for predicate handling
|
|
--
|
|
|
|
--
|
|
-- Test that restrictions that are always true are ignored, and that are always
|
|
-- false are replaced with constant-FALSE
|
|
--
|
|
-- Currently we only check for NullTest quals and OR clauses that include
|
|
-- NullTest quals. We may extend it in the future.
|
|
--
|
|
CREATE TABLE pred_tab (a int NOT NULL, b int, c int NOT NULL);
|
|
|
|
--
|
|
-- Test restriction clauses
|
|
--
|
|
|
|
-- Ensure the IS_NOT_NULL qual is ignored when the column is non-nullable
|
|
EXPLAIN (COSTS OFF)
|
|
SELECT * FROM pred_tab t WHERE t.a IS NOT NULL;
|
|
|
|
-- Ensure the IS_NOT_NULL qual is not ignored on a nullable column
|
|
EXPLAIN (COSTS OFF)
|
|
SELECT * FROM pred_tab t WHERE t.b IS NOT NULL;
|
|
|
|
-- Ensure the IS_NULL qual is reduced to constant-FALSE for non-nullable
|
|
-- columns
|
|
EXPLAIN (COSTS OFF)
|
|
SELECT * FROM pred_tab t WHERE t.a IS NULL;
|
|
|
|
-- Ensure the IS_NULL qual is not reduced to constant-FALSE on nullable
|
|
-- columns
|
|
EXPLAIN (COSTS OFF)
|
|
SELECT * FROM pred_tab t WHERE t.b IS NULL;
|
|
|
|
--
|
|
-- Tests for OR clauses in restriction clauses
|
|
--
|
|
|
|
-- Ensure the OR clause is ignored when an OR branch is always true
|
|
EXPLAIN (COSTS OFF)
|
|
SELECT * FROM pred_tab t WHERE t.a IS NOT NULL OR t.b = 1;
|
|
|
|
-- Ensure the OR clause is not ignored for NullTests that can't be proven
|
|
-- always true
|
|
EXPLAIN (COSTS OFF)
|
|
SELECT * FROM pred_tab t WHERE t.b IS NOT NULL OR t.a = 1;
|
|
|
|
-- Ensure the OR clause is reduced to constant-FALSE when all branches are
|
|
-- provably false
|
|
EXPLAIN (COSTS OFF)
|
|
SELECT * FROM pred_tab t WHERE t.a IS NULL OR t.c IS NULL;
|
|
|
|
-- Ensure the OR clause is not reduced to constant-FALSE when not all branches
|
|
-- are provably false
|
|
EXPLAIN (COSTS OFF)
|
|
SELECT * FROM pred_tab t WHERE t.b IS NULL OR t.c IS NULL;
|
|
|
|
--
|
|
-- Test join clauses
|
|
--
|
|
|
|
-- Ensure the IS_NOT_NULL qual is ignored, since a) it's on a NOT NULL column,
|
|
-- and b) its Var is not nullable by any outer joins
|
|
EXPLAIN (COSTS OFF)
|
|
SELECT * FROM pred_tab t1
|
|
LEFT JOIN pred_tab t2 ON TRUE
|
|
LEFT JOIN pred_tab t3 ON t2.a IS NOT NULL;
|
|
|
|
-- Ensure the IS_NOT_NULL qual is not ignored when columns are made nullable
|
|
-- by an outer join
|
|
EXPLAIN (COSTS OFF)
|
|
SELECT * FROM pred_tab t1
|
|
LEFT JOIN pred_tab t2 ON t1.a = 1
|
|
LEFT JOIN pred_tab t3 ON t2.a IS NOT NULL;
|
|
|
|
-- Ensure the IS_NULL qual is reduced to constant-FALSE, since a) it's on a NOT
|
|
-- NULL column, and b) its Var is not nullable by any outer joins
|
|
EXPLAIN (COSTS OFF)
|
|
SELECT * FROM pred_tab t1
|
|
LEFT JOIN pred_tab t2 ON TRUE
|
|
LEFT JOIN pred_tab t3 ON t2.a IS NULL AND t2.b = 1;
|
|
|
|
-- Ensure the IS_NULL qual is not reduced to constant-FALSE when the column is
|
|
-- nullable by an outer join
|
|
EXPLAIN (COSTS OFF)
|
|
SELECT * FROM pred_tab t1
|
|
LEFT JOIN pred_tab t2 ON t1.a = 1
|
|
LEFT JOIN pred_tab t3 ON t2.a IS NULL;
|
|
|
|
--
|
|
-- Tests for OR clauses in join clauses
|
|
--
|
|
|
|
-- Ensure the OR clause is ignored when an OR branch is provably always true
|
|
EXPLAIN (COSTS OFF)
|
|
SELECT * FROM pred_tab t1
|
|
LEFT JOIN pred_tab t2 ON TRUE
|
|
LEFT JOIN pred_tab t3 ON t2.a IS NOT NULL OR t2.b = 1;
|
|
|
|
-- Ensure the NullTest is not ignored when the column is nullable by an outer
|
|
-- join
|
|
EXPLAIN (COSTS OFF)
|
|
SELECT * FROM pred_tab t1
|
|
LEFT JOIN pred_tab t2 ON t1.a = 1
|
|
LEFT JOIN pred_tab t3 ON t2.a IS NOT NULL OR t2.b = 1;
|
|
|
|
-- Ensure the OR clause is reduced to constant-FALSE when all OR branches are
|
|
-- provably false
|
|
EXPLAIN (COSTS OFF)
|
|
SELECT * FROM pred_tab t1
|
|
LEFT JOIN pred_tab t2 ON TRUE
|
|
LEFT JOIN pred_tab t3 ON (t2.a IS NULL OR t2.c IS NULL) AND t2.b = 1;
|
|
|
|
-- Ensure the OR clause is not reduced to constant-FALSE when a column is
|
|
-- made nullable from an outer join
|
|
EXPLAIN (COSTS OFF)
|
|
SELECT * FROM pred_tab t1
|
|
LEFT JOIN pred_tab t2 ON t1.a = 1
|
|
LEFT JOIN pred_tab t3 ON t2.a IS NULL OR t2.c IS NULL;
|
|
|
|
DROP TABLE pred_tab;
|
|
|
|
-- Validate we handle IS NULL and IS NOT NULL quals correctly with inheritance
|
|
-- parents.
|
|
CREATE TABLE pred_parent (a int);
|
|
CREATE TABLE pred_child () INHERITS (pred_parent);
|
|
ALTER TABLE ONLY pred_parent ALTER a SET NOT NULL;
|
|
|
|
-- Ensure that the scan on pred_child contains the IS NOT NULL qual.
|
|
EXPLAIN (COSTS OFF)
|
|
SELECT * FROM pred_parent WHERE a IS NOT NULL;
|
|
|
|
-- Ensure we only scan pred_child and not pred_parent
|
|
EXPLAIN (COSTS OFF)
|
|
SELECT * FROM pred_parent WHERE a IS NULL;
|
|
|
|
ALTER TABLE pred_parent ALTER a DROP NOT NULL;
|
|
ALTER TABLE pred_child ALTER a SET NOT NULL;
|
|
|
|
-- Ensure the IS NOT NULL qual is removed from the pred_child scan.
|
|
EXPLAIN (COSTS OFF)
|
|
SELECT * FROM pred_parent WHERE a IS NOT NULL;
|
|
|
|
-- Ensure we only scan pred_parent and not pred_child
|
|
EXPLAIN (COSTS OFF)
|
|
SELECT * FROM pred_parent WHERE a IS NULL;
|
|
|
|
DROP TABLE pred_parent, pred_child;
|