-- -- JOIN -- Test JOIN clauses -- CREATE TABLE J1_TBL ( i integer, j integer, t text ); CREATE TABLE J2_TBL ( i integer, k integer ); INSERT INTO J1_TBL VALUES (1, 4, 'one'); INSERT INTO J1_TBL VALUES (2, 3, 'two'); INSERT INTO J1_TBL VALUES (3, 2, 'three'); INSERT INTO J1_TBL VALUES (4, 1, 'four'); INSERT INTO J1_TBL VALUES (5, 0, 'five'); INSERT INTO J1_TBL VALUES (6, 6, 'six'); INSERT INTO J1_TBL VALUES (7, 7, 'seven'); INSERT INTO J1_TBL VALUES (8, 8, 'eight'); INSERT INTO J1_TBL VALUES (0, NULL, 'zero'); INSERT INTO J1_TBL VALUES (NULL, NULL, 'null'); INSERT INTO J1_TBL VALUES (NULL, 0, 'zero'); INSERT INTO J2_TBL VALUES (1, -1); INSERT INTO J2_TBL VALUES (2, 2); INSERT INTO J2_TBL VALUES (3, -3); INSERT INTO J2_TBL VALUES (2, 4); INSERT INTO J2_TBL VALUES (5, -5); INSERT INTO J2_TBL VALUES (5, -5); INSERT INTO J2_TBL VALUES (0, NULL); INSERT INTO J2_TBL VALUES (NULL, NULL); INSERT INTO J2_TBL VALUES (NULL, 0); -- useful in some tests below create temp table onerow(); insert into onerow default values; analyze onerow; -- -- CORRELATION NAMES -- Make sure that table/column aliases are supported -- before diving into more complex join syntax. -- SELECT * FROM J1_TBL AS tx; i | j | t ---+---+------- 1 | 4 | one 2 | 3 | two 3 | 2 | three 4 | 1 | four 5 | 0 | five 6 | 6 | six 7 | 7 | seven 8 | 8 | eight 0 | | zero | | null | 0 | zero (11 rows) SELECT * FROM J1_TBL tx; i | j | t ---+---+------- 1 | 4 | one 2 | 3 | two 3 | 2 | three 4 | 1 | four 5 | 0 | five 6 | 6 | six 7 | 7 | seven 8 | 8 | eight 0 | | zero | | null | 0 | zero (11 rows) SELECT * FROM J1_TBL AS t1 (a, b, c); a | b | c ---+---+------- 1 | 4 | one 2 | 3 | two 3 | 2 | three 4 | 1 | four 5 | 0 | five 6 | 6 | six 7 | 7 | seven 8 | 8 | eight 0 | | zero | | null | 0 | zero (11 rows) SELECT * FROM J1_TBL t1 (a, b, c); a | b | c ---+---+------- 1 | 4 | one 2 | 3 | two 3 | 2 | three 4 | 1 | four 5 | 0 | five 6 | 6 | six 7 | 7 | seven 8 | 8 | eight 0 | | zero | | null | 0 | zero (11 rows) SELECT * FROM J1_TBL t1 (a, b, c), J2_TBL t2 (d, e); a | b | c | d | e ---+---+-------+---+---- 1 | 4 | one | 1 | -1 2 | 3 | two | 1 | -1 3 | 2 | three | 1 | -1 4 | 1 | four | 1 | -1 5 | 0 | five | 1 | -1 6 | 6 | six | 1 | -1 7 | 7 | seven | 1 | -1 8 | 8 | eight | 1 | -1 0 | | zero | 1 | -1 | | null | 1 | -1 | 0 | zero | 1 | -1 1 | 4 | one | 2 | 2 2 | 3 | two | 2 | 2 3 | 2 | three | 2 | 2 4 | 1 | four | 2 | 2 5 | 0 | five | 2 | 2 6 | 6 | six | 2 | 2 7 | 7 | seven | 2 | 2 8 | 8 | eight | 2 | 2 0 | | zero | 2 | 2 | | null | 2 | 2 | 0 | zero | 2 | 2 1 | 4 | one | 3 | -3 2 | 3 | two | 3 | -3 3 | 2 | three | 3 | -3 4 | 1 | four | 3 | -3 5 | 0 | five | 3 | -3 6 | 6 | six | 3 | -3 7 | 7 | seven | 3 | -3 8 | 8 | eight | 3 | -3 0 | | zero | 3 | -3 | | null | 3 | -3 | 0 | zero | 3 | -3 1 | 4 | one | 2 | 4 2 | 3 | two | 2 | 4 3 | 2 | three | 2 | 4 4 | 1 | four | 2 | 4 5 | 0 | five | 2 | 4 6 | 6 | six | 2 | 4 7 | 7 | seven | 2 | 4 8 | 8 | eight | 2 | 4 0 | | zero | 2 | 4 | | null | 2 | 4 | 0 | zero | 2 | 4 1 | 4 | one | 5 | -5 2 | 3 | two | 5 | -5 3 | 2 | three | 5 | -5 4 | 1 | four | 5 | -5 5 | 0 | five | 5 | -5 6 | 6 | six | 5 | -5 7 | 7 | seven | 5 | -5 8 | 8 | eight | 5 | -5 0 | | zero | 5 | -5 | | null | 5 | -5 | 0 | zero | 5 | -5 1 | 4 | one | 5 | -5 2 | 3 | two | 5 | -5 3 | 2 | three | 5 | -5 4 | 1 | four | 5 | -5 5 | 0 | five | 5 | -5 6 | 6 | six | 5 | -5 7 | 7 | seven | 5 | -5 8 | 8 | eight | 5 | -5 0 | | zero | 5 | -5 | | null | 5 | -5 | 0 | zero | 5 | -5 1 | 4 | one | 0 | 2 | 3 | two | 0 | 3 | 2 | three | 0 | 4 | 1 | four | 0 | 5 | 0 | five | 0 | 6 | 6 | six | 0 | 7 | 7 | seven | 0 | 8 | 8 | eight | 0 | 0 | | zero | 0 | | | null | 0 | | 0 | zero | 0 | 1 | 4 | one | | 2 | 3 | two | | 3 | 2 | three | | 4 | 1 | four | | 5 | 0 | five | | 6 | 6 | six | | 7 | 7 | seven | | 8 | 8 | eight | | 0 | | zero | | | | null | | | 0 | zero | | 1 | 4 | one | | 0 2 | 3 | two | | 0 3 | 2 | three | | 0 4 | 1 | four | | 0 5 | 0 | five | | 0 6 | 6 | six | | 0 7 | 7 | seven | | 0 8 | 8 | eight | | 0 0 | | zero | | 0 | | null | | 0 | 0 | zero | | 0 (99 rows) SELECT t1.a, t2.e FROM J1_TBL t1 (a, b, c), J2_TBL t2 (d, e) WHERE t1.a = t2.d; a | e ---+---- 0 | 1 | -1 2 | 2 2 | 4 3 | -3 5 | -5 5 | -5 (7 rows) -- -- CROSS JOIN -- Qualifications are not allowed on cross joins, -- which degenerate into a standard unqualified inner join. -- SELECT * FROM J1_TBL CROSS JOIN J2_TBL; i | j | t | i | k ---+---+-------+---+---- 1 | 4 | one | 1 | -1 2 | 3 | two | 1 | -1 3 | 2 | three | 1 | -1 4 | 1 | four | 1 | -1 5 | 0 | five | 1 | -1 6 | 6 | six | 1 | -1 7 | 7 | seven | 1 | -1 8 | 8 | eight | 1 | -1 0 | | zero | 1 | -1 | | null | 1 | -1 | 0 | zero | 1 | -1 1 | 4 | one | 2 | 2 2 | 3 | two | 2 | 2 3 | 2 | three | 2 | 2 4 | 1 | four | 2 | 2 5 | 0 | five | 2 | 2 6 | 6 | six | 2 | 2 7 | 7 | seven | 2 | 2 8 | 8 | eight | 2 | 2 0 | | zero | 2 | 2 | | null | 2 | 2 | 0 | zero | 2 | 2 1 | 4 | one | 3 | -3 2 | 3 | two | 3 | -3 3 | 2 | three | 3 | -3 4 | 1 | four | 3 | -3 5 | 0 | five | 3 | -3 6 | 6 | six | 3 | -3 7 | 7 | seven | 3 | -3 8 | 8 | eight | 3 | -3 0 | | zero | 3 | -3 | | null | 3 | -3 | 0 | zero | 3 | -3 1 | 4 | one | 2 | 4 2 | 3 | two | 2 | 4 3 | 2 | three | 2 | 4 4 | 1 | four | 2 | 4 5 | 0 | five | 2 | 4 6 | 6 | six | 2 | 4 7 | 7 | seven | 2 | 4 8 | 8 | eight | 2 | 4 0 | | zero | 2 | 4 | | null | 2 | 4 | 0 | zero | 2 | 4 1 | 4 | one | 5 | -5 2 | 3 | two | 5 | -5 3 | 2 | three | 5 | -5 4 | 1 | four | 5 | -5 5 | 0 | five | 5 | -5 6 | 6 | six | 5 | -5 7 | 7 | seven | 5 | -5 8 | 8 | eight | 5 | -5 0 | | zero | 5 | -5 | | null | 5 | -5 | 0 | zero | 5 | -5 1 | 4 | one | 5 | -5 2 | 3 | two | 5 | -5 3 | 2 | three | 5 | -5 4 | 1 | four | 5 | -5 5 | 0 | five | 5 | -5 6 | 6 | six | 5 | -5 7 | 7 | seven | 5 | -5 8 | 8 | eight | 5 | -5 0 | | zero | 5 | -5 | | null | 5 | -5 | 0 | zero | 5 | -5 1 | 4 | one | 0 | 2 | 3 | two | 0 | 3 | 2 | three | 0 | 4 | 1 | four | 0 | 5 | 0 | five | 0 | 6 | 6 | six | 0 | 7 | 7 | seven | 0 | 8 | 8 | eight | 0 | 0 | | zero | 0 | | | null | 0 | | 0 | zero | 0 | 1 | 4 | one | | 2 | 3 | two | | 3 | 2 | three | | 4 | 1 | four | | 5 | 0 | five | | 6 | 6 | six | | 7 | 7 | seven | | 8 | 8 | eight | | 0 | | zero | | | | null | | | 0 | zero | | 1 | 4 | one | | 0 2 | 3 | two | | 0 3 | 2 | three | | 0 4 | 1 | four | | 0 5 | 0 | five | | 0 6 | 6 | six | | 0 7 | 7 | seven | | 0 8 | 8 | eight | | 0 0 | | zero | | 0 | | null | | 0 | 0 | zero | | 0 (99 rows) -- ambiguous column SELECT i, k, t FROM J1_TBL CROSS JOIN J2_TBL; ERROR: column reference "i" is ambiguous LINE 1: SELECT i, k, t ^ -- resolve previous ambiguity by specifying the table name SELECT t1.i, k, t FROM J1_TBL t1 CROSS JOIN J2_TBL t2; i | k | t ---+----+------- 1 | -1 | one 2 | -1 | two 3 | -1 | three 4 | -1 | four 5 | -1 | five 6 | -1 | six 7 | -1 | seven 8 | -1 | eight 0 | -1 | zero | -1 | null | -1 | zero 1 | 2 | one 2 | 2 | two 3 | 2 | three 4 | 2 | four 5 | 2 | five 6 | 2 | six 7 | 2 | seven 8 | 2 | eight 0 | 2 | zero | 2 | null | 2 | zero 1 | -3 | one 2 | -3 | two 3 | -3 | three 4 | -3 | four 5 | -3 | five 6 | -3 | six 7 | -3 | seven 8 | -3 | eight 0 | -3 | zero | -3 | null | -3 | zero 1 | 4 | one 2 | 4 | two 3 | 4 | three 4 | 4 | four 5 | 4 | five 6 | 4 | six 7 | 4 | seven 8 | 4 | eight 0 | 4 | zero | 4 | null | 4 | zero 1 | -5 | one 2 | -5 | two 3 | -5 | three 4 | -5 | four 5 | -5 | five 6 | -5 | six 7 | -5 | seven 8 | -5 | eight 0 | -5 | zero | -5 | null | -5 | zero 1 | -5 | one 2 | -5 | two 3 | -5 | three 4 | -5 | four 5 | -5 | five 6 | -5 | six 7 | -5 | seven 8 | -5 | eight 0 | -5 | zero | -5 | null | -5 | zero 1 | | one 2 | | two 3 | | three 4 | | four 5 | | five 6 | | six 7 | | seven 8 | | eight 0 | | zero | | null | | zero 1 | | one 2 | | two 3 | | three 4 | | four 5 | | five 6 | | six 7 | | seven 8 | | eight 0 | | zero | | null | | zero 1 | 0 | one 2 | 0 | two 3 | 0 | three 4 | 0 | four 5 | 0 | five 6 | 0 | six 7 | 0 | seven 8 | 0 | eight 0 | 0 | zero | 0 | null | 0 | zero (99 rows) SELECT ii, tt, kk FROM (J1_TBL CROSS JOIN J2_TBL) AS tx (ii, jj, tt, ii2, kk); ii | tt | kk ----+-------+---- 1 | one | -1 2 | two | -1 3 | three | -1 4 | four | -1 5 | five | -1 6 | six | -1 7 | seven | -1 8 | eight | -1 0 | zero | -1 | null | -1 | zero | -1 1 | one | 2 2 | two | 2 3 | three | 2 4 | four | 2 5 | five | 2 6 | six | 2 7 | seven | 2 8 | eight | 2 0 | zero | 2 | null | 2 | zero | 2 1 | one | -3 2 | two | -3 3 | three | -3 4 | four | -3 5 | five | -3 6 | six | -3 7 | seven | -3 8 | eight | -3 0 | zero | -3 | null | -3 | zero | -3 1 | one | 4 2 | two | 4 3 | three | 4 4 | four | 4 5 | five | 4 6 | six | 4 7 | seven | 4 8 | eight | 4 0 | zero | 4 | null | 4 | zero | 4 1 | one | -5 2 | two | -5 3 | three | -5 4 | four | -5 5 | five | -5 6 | six | -5 7 | seven | -5 8 | eight | -5 0 | zero | -5 | null | -5 | zero | -5 1 | one | -5 2 | two | -5 3 | three | -5 4 | four | -5 5 | five | -5 6 | six | -5 7 | seven | -5 8 | eight | -5 0 | zero | -5 | null | -5 | zero | -5 1 | one | 2 | two | 3 | three | 4 | four | 5 | five | 6 | six | 7 | seven | 8 | eight | 0 | zero | | null | | zero | 1 | one | 2 | two | 3 | three | 4 | four | 5 | five | 6 | six | 7 | seven | 8 | eight | 0 | zero | | null | | zero | 1 | one | 0 2 | two | 0 3 | three | 0 4 | four | 0 5 | five | 0 6 | six | 0 7 | seven | 0 8 | eight | 0 0 | zero | 0 | null | 0 | zero | 0 (99 rows) SELECT tx.ii, tx.jj, tx.kk FROM (J1_TBL t1 (a, b, c) CROSS JOIN J2_TBL t2 (d, e)) AS tx (ii, jj, tt, ii2, kk); ii | jj | kk ----+----+---- 1 | 4 | -1 2 | 3 | -1 3 | 2 | -1 4 | 1 | -1 5 | 0 | -1 6 | 6 | -1 7 | 7 | -1 8 | 8 | -1 0 | | -1 | | -1 | 0 | -1 1 | 4 | 2 2 | 3 | 2 3 | 2 | 2 4 | 1 | 2 5 | 0 | 2 6 | 6 | 2 7 | 7 | 2 8 | 8 | 2 0 | | 2 | | 2 | 0 | 2 1 | 4 | -3 2 | 3 | -3 3 | 2 | -3 4 | 1 | -3 5 | 0 | -3 6 | 6 | -3 7 | 7 | -3 8 | 8 | -3 0 | | -3 | | -3 | 0 | -3 1 | 4 | 4 2 | 3 | 4 3 | 2 | 4 4 | 1 | 4 5 | 0 | 4 6 | 6 | 4 7 | 7 | 4 8 | 8 | 4 0 | | 4 | | 4 | 0 | 4 1 | 4 | -5 2 | 3 | -5 3 | 2 | -5 4 | 1 | -5 5 | 0 | -5 6 | 6 | -5 7 | 7 | -5 8 | 8 | -5 0 | | -5 | | -5 | 0 | -5 1 | 4 | -5 2 | 3 | -5 3 | 2 | -5 4 | 1 | -5 5 | 0 | -5 6 | 6 | -5 7 | 7 | -5 8 | 8 | -5 0 | | -5 | | -5 | 0 | -5 1 | 4 | 2 | 3 | 3 | 2 | 4 | 1 | 5 | 0 | 6 | 6 | 7 | 7 | 8 | 8 | 0 | | | | | 0 | 1 | 4 | 2 | 3 | 3 | 2 | 4 | 1 | 5 | 0 | 6 | 6 | 7 | 7 | 8 | 8 | 0 | | | | | 0 | 1 | 4 | 0 2 | 3 | 0 3 | 2 | 0 4 | 1 | 0 5 | 0 | 0 6 | 6 | 0 7 | 7 | 0 8 | 8 | 0 0 | | 0 | | 0 | 0 | 0 (99 rows) SELECT * FROM J1_TBL CROSS JOIN J2_TBL a CROSS JOIN J2_TBL b; i | j | t | i | k | i | k ---+---+-------+---+----+---+---- 1 | 4 | one | 1 | -1 | 1 | -1 1 | 4 | one | 1 | -1 | 2 | 2 1 | 4 | one | 1 | -1 | 3 | -3 1 | 4 | one | 1 | -1 | 2 | 4 1 | 4 | one | 1 | -1 | 5 | -5 1 | 4 | one | 1 | -1 | 5 | -5 1 | 4 | one | 1 | -1 | 0 | 1 | 4 | one | 1 | -1 | | 1 | 4 | one | 1 | -1 | | 0 2 | 3 | two | 1 | -1 | 1 | -1 2 | 3 | two | 1 | -1 | 2 | 2 2 | 3 | two | 1 | -1 | 3 | -3 2 | 3 | two | 1 | -1 | 2 | 4 2 | 3 | two | 1 | -1 | 5 | -5 2 | 3 | two | 1 | -1 | 5 | -5 2 | 3 | two | 1 | -1 | 0 | 2 | 3 | two | 1 | -1 | | 2 | 3 | two | 1 | -1 | | 0 3 | 2 | three | 1 | -1 | 1 | -1 3 | 2 | three | 1 | -1 | 2 | 2 3 | 2 | three | 1 | -1 | 3 | -3 3 | 2 | three | 1 | -1 | 2 | 4 3 | 2 | three | 1 | -1 | 5 | -5 3 | 2 | three | 1 | -1 | 5 | -5 3 | 2 | three | 1 | -1 | 0 | 3 | 2 | three | 1 | -1 | | 3 | 2 | three | 1 | -1 | | 0 4 | 1 | four | 1 | -1 | 1 | -1 4 | 1 | four | 1 | -1 | 2 | 2 4 | 1 | four | 1 | -1 | 3 | -3 4 | 1 | four | 1 | -1 | 2 | 4 4 | 1 | four | 1 | -1 | 5 | -5 4 | 1 | four | 1 | -1 | 5 | -5 4 | 1 | four | 1 | -1 | 0 | 4 | 1 | four | 1 | -1 | | 4 | 1 | four | 1 | -1 | | 0 5 | 0 | five | 1 | -1 | 1 | -1 5 | 0 | five | 1 | -1 | 2 | 2 5 | 0 | five | 1 | -1 | 3 | -3 5 | 0 | five | 1 | -1 | 2 | 4 5 | 0 | five | 1 | -1 | 5 | -5 5 | 0 | five | 1 | -1 | 5 | -5 5 | 0 | five | 1 | -1 | 0 | 5 | 0 | five | 1 | -1 | | 5 | 0 | five | 1 | -1 | | 0 6 | 6 | six | 1 | -1 | 1 | -1 6 | 6 | six | 1 | -1 | 2 | 2 6 | 6 | six | 1 | -1 | 3 | -3 6 | 6 | six | 1 | -1 | 2 | 4 6 | 6 | six | 1 | -1 | 5 | -5 6 | 6 | six | 1 | -1 | 5 | -5 6 | 6 | six | 1 | -1 | 0 | 6 | 6 | six | 1 | -1 | | 6 | 6 | six | 1 | -1 | | 0 7 | 7 | seven | 1 | -1 | 1 | -1 7 | 7 | seven | 1 | -1 | 2 | 2 7 | 7 | seven | 1 | -1 | 3 | -3 7 | 7 | seven | 1 | -1 | 2 | 4 7 | 7 | seven | 1 | -1 | 5 | -5 7 | 7 | seven | 1 | -1 | 5 | -5 7 | 7 | seven | 1 | -1 | 0 | 7 | 7 | seven | 1 | -1 | | 7 | 7 | seven | 1 | -1 | | 0 8 | 8 | eight | 1 | -1 | 1 | -1 8 | 8 | eight | 1 | -1 | 2 | 2 8 | 8 | eight | 1 | -1 | 3 | -3 8 | 8 | eight | 1 | -1 | 2 | 4 8 | 8 | eight | 1 | -1 | 5 | -5 8 | 8 | eight | 1 | -1 | 5 | -5 8 | 8 | eight | 1 | -1 | 0 | 8 | 8 | eight | 1 | -1 | | 8 | 8 | eight | 1 | -1 | | 0 0 | | zero | 1 | -1 | 1 | -1 0 | | zero | 1 | -1 | 2 | 2 0 | | zero | 1 | -1 | 3 | -3 0 | | zero | 1 | -1 | 2 | 4 0 | | zero | 1 | -1 | 5 | -5 0 | | zero | 1 | -1 | 5 | -5 0 | | zero | 1 | -1 | 0 | 0 | | zero | 1 | -1 | | 0 | | zero | 1 | -1 | | 0 | | null | 1 | -1 | 1 | -1 | | null | 1 | -1 | 2 | 2 | | null | 1 | -1 | 3 | -3 | | null | 1 | -1 | 2 | 4 | | null | 1 | -1 | 5 | -5 | | null | 1 | -1 | 5 | -5 | | null | 1 | -1 | 0 | | | null | 1 | -1 | | | | null | 1 | -1 | | 0 | 0 | zero | 1 | -1 | 1 | -1 | 0 | zero | 1 | -1 | 2 | 2 | 0 | zero | 1 | -1 | 3 | -3 | 0 | zero | 1 | -1 | 2 | 4 | 0 | zero | 1 | -1 | 5 | -5 | 0 | zero | 1 | -1 | 5 | -5 | 0 | zero | 1 | -1 | 0 | | 0 | zero | 1 | -1 | | | 0 | zero | 1 | -1 | | 0 1 | 4 | one | 2 | 2 | 1 | -1 1 | 4 | one | 2 | 2 | 2 | 2 1 | 4 | one | 2 | 2 | 3 | -3 1 | 4 | one | 2 | 2 | 2 | 4 1 | 4 | one | 2 | 2 | 5 | -5 1 | 4 | one | 2 | 2 | 5 | -5 1 | 4 | one | 2 | 2 | 0 | 1 | 4 | one | 2 | 2 | | 1 | 4 | one | 2 | 2 | | 0 2 | 3 | two | 2 | 2 | 1 | -1 2 | 3 | two | 2 | 2 | 2 | 2 2 | 3 | two | 2 | 2 | 3 | -3 2 | 3 | two | 2 | 2 | 2 | 4 2 | 3 | two | 2 | 2 | 5 | -5 2 | 3 | two | 2 | 2 | 5 | -5 2 | 3 | two | 2 | 2 | 0 | 2 | 3 | two | 2 | 2 | | 2 | 3 | two | 2 | 2 | | 0 3 | 2 | three | 2 | 2 | 1 | -1 3 | 2 | three | 2 | 2 | 2 | 2 3 | 2 | three | 2 | 2 | 3 | -3 3 | 2 | three | 2 | 2 | 2 | 4 3 | 2 | three | 2 | 2 | 5 | -5 3 | 2 | three | 2 | 2 | 5 | -5 3 | 2 | three | 2 | 2 | 0 | 3 | 2 | three | 2 | 2 | | 3 | 2 | three | 2 | 2 | | 0 4 | 1 | four | 2 | 2 | 1 | -1 4 | 1 | four | 2 | 2 | 2 | 2 4 | 1 | four | 2 | 2 | 3 | -3 4 | 1 | four | 2 | 2 | 2 | 4 4 | 1 | four | 2 | 2 | 5 | -5 4 | 1 | four | 2 | 2 | 5 | -5 4 | 1 | four | 2 | 2 | 0 | 4 | 1 | four | 2 | 2 | | 4 | 1 | four | 2 | 2 | | 0 5 | 0 | five | 2 | 2 | 1 | -1 5 | 0 | five | 2 | 2 | 2 | 2 5 | 0 | five | 2 | 2 | 3 | -3 5 | 0 | five | 2 | 2 | 2 | 4 5 | 0 | five | 2 | 2 | 5 | -5 5 | 0 | five | 2 | 2 | 5 | -5 5 | 0 | five | 2 | 2 | 0 | 5 | 0 | five | 2 | 2 | | 5 | 0 | five | 2 | 2 | | 0 6 | 6 | six | 2 | 2 | 1 | -1 6 | 6 | six | 2 | 2 | 2 | 2 6 | 6 | six | 2 | 2 | 3 | -3 6 | 6 | six | 2 | 2 | 2 | 4 6 | 6 | six | 2 | 2 | 5 | -5 6 | 6 | six | 2 | 2 | 5 | -5 6 | 6 | six | 2 | 2 | 0 | 6 | 6 | six | 2 | 2 | | 6 | 6 | six | 2 | 2 | | 0 7 | 7 | seven | 2 | 2 | 1 | -1 7 | 7 | seven | 2 | 2 | 2 | 2 7 | 7 | seven | 2 | 2 | 3 | -3 7 | 7 | seven | 2 | 2 | 2 | 4 7 | 7 | seven | 2 | 2 | 5 | -5 7 | 7 | seven | 2 | 2 | 5 | -5 7 | 7 | seven | 2 | 2 | 0 | 7 | 7 | seven | 2 | 2 | | 7 | 7 | seven | 2 | 2 | | 0 8 | 8 | eight | 2 | 2 | 1 | -1 8 | 8 | eight | 2 | 2 | 2 | 2 8 | 8 | eight | 2 | 2 | 3 | -3 8 | 8 | eight | 2 | 2 | 2 | 4 8 | 8 | eight | 2 | 2 | 5 | -5 8 | 8 | eight | 2 | 2 | 5 | -5 8 | 8 | eight | 2 | 2 | 0 | 8 | 8 | eight | 2 | 2 | | 8 | 8 | eight | 2 | 2 | | 0 0 | | zero | 2 | 2 | 1 | -1 0 | | zero | 2 | 2 | 2 | 2 0 | | zero | 2 | 2 | 3 | -3 0 | | zero | 2 | 2 | 2 | 4 0 | | zero | 2 | 2 | 5 | -5 0 | | zero | 2 | 2 | 5 | -5 0 | | zero | 2 | 2 | 0 | 0 | | zero | 2 | 2 | | 0 | | zero | 2 | 2 | | 0 | | null | 2 | 2 | 1 | -1 | | null | 2 | 2 | 2 | 2 | | null | 2 | 2 | 3 | -3 | | null | 2 | 2 | 2 | 4 | | null | 2 | 2 | 5 | -5 | | null | 2 | 2 | 5 | -5 | | null | 2 | 2 | 0 | | | null | 2 | 2 | | | | null | 2 | 2 | | 0 | 0 | zero | 2 | 2 | 1 | -1 | 0 | zero | 2 | 2 | 2 | 2 | 0 | zero | 2 | 2 | 3 | -3 | 0 | zero | 2 | 2 | 2 | 4 | 0 | zero | 2 | 2 | 5 | -5 | 0 | zero | 2 | 2 | 5 | -5 | 0 | zero | 2 | 2 | 0 | | 0 | zero | 2 | 2 | | | 0 | zero | 2 | 2 | | 0 1 | 4 | one | 3 | -3 | 1 | -1 1 | 4 | one | 3 | -3 | 2 | 2 1 | 4 | one | 3 | -3 | 3 | -3 1 | 4 | one | 3 | -3 | 2 | 4 1 | 4 | one | 3 | -3 | 5 | -5 1 | 4 | one | 3 | -3 | 5 | -5 1 | 4 | one | 3 | -3 | 0 | 1 | 4 | one | 3 | -3 | | 1 | 4 | one | 3 | -3 | | 0 2 | 3 | two | 3 | -3 | 1 | -1 2 | 3 | two | 3 | -3 | 2 | 2 2 | 3 | two | 3 | -3 | 3 | -3 2 | 3 | two | 3 | -3 | 2 | 4 2 | 3 | two | 3 | -3 | 5 | -5 2 | 3 | two | 3 | -3 | 5 | -5 2 | 3 | two | 3 | -3 | 0 | 2 | 3 | two | 3 | -3 | | 2 | 3 | two | 3 | -3 | | 0 3 | 2 | three | 3 | -3 | 1 | -1 3 | 2 | three | 3 | -3 | 2 | 2 3 | 2 | three | 3 | -3 | 3 | -3 3 | 2 | three | 3 | -3 | 2 | 4 3 | 2 | three | 3 | -3 | 5 | -5 3 | 2 | three | 3 | -3 | 5 | -5 3 | 2 | three | 3 | -3 | 0 | 3 | 2 | three | 3 | -3 | | 3 | 2 | three | 3 | -3 | | 0 4 | 1 | four | 3 | -3 | 1 | -1 4 | 1 | four | 3 | -3 | 2 | 2 4 | 1 | four | 3 | -3 | 3 | -3 4 | 1 | four | 3 | -3 | 2 | 4 4 | 1 | four | 3 | -3 | 5 | -5 4 | 1 | four | 3 | -3 | 5 | -5 4 | 1 | four | 3 | -3 | 0 | 4 | 1 | four | 3 | -3 | | 4 | 1 | four | 3 | -3 | | 0 5 | 0 | five | 3 | -3 | 1 | -1 5 | 0 | five | 3 | -3 | 2 | 2 5 | 0 | five | 3 | -3 | 3 | -3 5 | 0 | five | 3 | -3 | 2 | 4 5 | 0 | five | 3 | -3 | 5 | -5 5 | 0 | five | 3 | -3 | 5 | -5 5 | 0 | five | 3 | -3 | 0 | 5 | 0 | five | 3 | -3 | | 5 | 0 | five | 3 | -3 | | 0 6 | 6 | six | 3 | -3 | 1 | -1 6 | 6 | six | 3 | -3 | 2 | 2 6 | 6 | six | 3 | -3 | 3 | -3 6 | 6 | six | 3 | -3 | 2 | 4 6 | 6 | six | 3 | -3 | 5 | -5 6 | 6 | six | 3 | -3 | 5 | -5 6 | 6 | six | 3 | -3 | 0 | 6 | 6 | six | 3 | -3 | | 6 | 6 | six | 3 | -3 | | 0 7 | 7 | seven | 3 | -3 | 1 | -1 7 | 7 | seven | 3 | -3 | 2 | 2 7 | 7 | seven | 3 | -3 | 3 | -3 7 | 7 | seven | 3 | -3 | 2 | 4 7 | 7 | seven | 3 | -3 | 5 | -5 7 | 7 | seven | 3 | -3 | 5 | -5 7 | 7 | seven | 3 | -3 | 0 | 7 | 7 | seven | 3 | -3 | | 7 | 7 | seven | 3 | -3 | | 0 8 | 8 | eight | 3 | -3 | 1 | -1 8 | 8 | eight | 3 | -3 | 2 | 2 8 | 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5 | 0 | five | | | | 5 | 0 | five | | | | 0 6 | 6 | six | | | 1 | -1 6 | 6 | six | | | 2 | 2 6 | 6 | six | | | 3 | -3 6 | 6 | six | | | 2 | 4 6 | 6 | six | | | 5 | -5 6 | 6 | six | | | 5 | -5 6 | 6 | six | | | 0 | 6 | 6 | six | | | | 6 | 6 | six | | | | 0 7 | 7 | seven | | | 1 | -1 7 | 7 | seven | | | 2 | 2 7 | 7 | seven | | | 3 | -3 7 | 7 | seven | | | 2 | 4 7 | 7 | seven | | | 5 | -5 7 | 7 | seven | | | 5 | -5 7 | 7 | seven | | | 0 | 7 | 7 | seven | | | | 7 | 7 | seven | | | | 0 8 | 8 | eight | | | 1 | -1 8 | 8 | eight | | | 2 | 2 8 | 8 | eight | | | 3 | -3 8 | 8 | eight | | | 2 | 4 8 | 8 | eight | | | 5 | -5 8 | 8 | eight | | | 5 | -5 8 | 8 | eight | | | 0 | 8 | 8 | eight | | | | 8 | 8 | eight | | | | 0 0 | | zero | | | 1 | -1 0 | | zero | | | 2 | 2 0 | | zero | | | 3 | -3 0 | | zero | | | 2 | 4 0 | | zero | | | 5 | -5 0 | | zero | | | 5 | -5 0 | | zero | | | 0 | 0 | | zero | | | | 0 | | zero | | | | 0 | | null | | | 1 | -1 | | null | | | 2 | 2 | | null | | | 3 | -3 | | null | | | 2 | 4 | | null | | | 5 | -5 | | null | | | 5 | -5 | | null | | | 0 | | | null | | | | | | null | | | | 0 | 0 | zero | | | 1 | -1 | 0 | zero | | | 2 | 2 | 0 | zero | | | 3 | -3 | 0 | zero | | | 2 | 4 | 0 | zero | | | 5 | -5 | 0 | zero | | | 5 | -5 | 0 | zero | | | 0 | | 0 | zero | | | | | 0 | zero | | | | 0 1 | 4 | one | | 0 | 1 | -1 1 | 4 | one | | 0 | 2 | 2 1 | 4 | one | | 0 | 3 | -3 1 | 4 | one | | 0 | 2 | 4 1 | 4 | one | | 0 | 5 | -5 1 | 4 | one | | 0 | 5 | -5 1 | 4 | one | | 0 | 0 | 1 | 4 | one | | 0 | | 1 | 4 | one | | 0 | | 0 2 | 3 | two | | 0 | 1 | -1 2 | 3 | two | | 0 | 2 | 2 2 | 3 | two | | 0 | 3 | -3 2 | 3 | two | | 0 | 2 | 4 2 | 3 | two | | 0 | 5 | -5 2 | 3 | two | | 0 | 5 | -5 2 | 3 | two | | 0 | 0 | 2 | 3 | two | | 0 | | 2 | 3 | two | | 0 | | 0 3 | 2 | three | | 0 | 1 | -1 3 | 2 | three | | 0 | 2 | 2 3 | 2 | three | | 0 | 3 | -3 3 | 2 | three | | 0 | 2 | 4 3 | 2 | three | | 0 | 5 | -5 3 | 2 | three | | 0 | 5 | -5 3 | 2 | three | | 0 | 0 | 3 | 2 | three | | 0 | | 3 | 2 | three | | 0 | | 0 4 | 1 | four | | 0 | 1 | -1 4 | 1 | four | | 0 | 2 | 2 4 | 1 | four | | 0 | 3 | -3 4 | 1 | four | | 0 | 2 | 4 4 | 1 | four | | 0 | 5 | -5 4 | 1 | four | | 0 | 5 | -5 4 | 1 | four | | 0 | 0 | 4 | 1 | four | | 0 | | 4 | 1 | four | | 0 | | 0 5 | 0 | five | | 0 | 1 | -1 5 | 0 | five | | 0 | 2 | 2 5 | 0 | five | | 0 | 3 | -3 5 | 0 | five | | 0 | 2 | 4 5 | 0 | five | | 0 | 5 | -5 5 | 0 | five | | 0 | 5 | -5 5 | 0 | five | | 0 | 0 | 5 | 0 | five | | 0 | | 5 | 0 | five | | 0 | | 0 6 | 6 | six | | 0 | 1 | -1 6 | 6 | six | | 0 | 2 | 2 6 | 6 | six | | 0 | 3 | -3 6 | 6 | six | | 0 | 2 | 4 6 | 6 | six | | 0 | 5 | -5 6 | 6 | six | | 0 | 5 | -5 6 | 6 | six | | 0 | 0 | 6 | 6 | six | | 0 | | 6 | 6 | six | | 0 | | 0 7 | 7 | seven | | 0 | 1 | -1 7 | 7 | seven | | 0 | 2 | 2 7 | 7 | seven | | 0 | 3 | -3 7 | 7 | seven | | 0 | 2 | 4 7 | 7 | seven | | 0 | 5 | -5 7 | 7 | seven | | 0 | 5 | -5 7 | 7 | seven | | 0 | 0 | 7 | 7 | seven | | 0 | | 7 | 7 | seven | | 0 | | 0 8 | 8 | eight | | 0 | 1 | -1 8 | 8 | eight | | 0 | 2 | 2 8 | 8 | eight | | 0 | 3 | -3 8 | 8 | eight | | 0 | 2 | 4 8 | 8 | eight | | 0 | 5 | -5 8 | 8 | eight | | 0 | 5 | -5 8 | 8 | eight | | 0 | 0 | 8 | 8 | eight | | 0 | | 8 | 8 | eight | | 0 | | 0 0 | | zero | | 0 | 1 | -1 0 | | zero | | 0 | 2 | 2 0 | | zero | | 0 | 3 | -3 0 | | zero | | 0 | 2 | 4 0 | | zero | | 0 | 5 | -5 0 | | zero | | 0 | 5 | -5 0 | | zero | | 0 | 0 | 0 | | zero | | 0 | | 0 | | zero | | 0 | | 0 | | null | | 0 | 1 | -1 | | null | | 0 | 2 | 2 | | null | | 0 | 3 | -3 | | null | | 0 | 2 | 4 | | null | | 0 | 5 | -5 | | null | | 0 | 5 | -5 | | null | | 0 | 0 | | | null | | 0 | | | | null | | 0 | | 0 | 0 | zero | | 0 | 1 | -1 | 0 | zero | | 0 | 2 | 2 | 0 | zero | | 0 | 3 | -3 | 0 | zero | | 0 | 2 | 4 | 0 | zero | | 0 | 5 | -5 | 0 | zero | | 0 | 5 | -5 | 0 | zero | | 0 | 0 | | 0 | zero | | 0 | | | 0 | zero | | 0 | | 0 (891 rows) -- -- -- Inner joins (equi-joins) -- -- -- -- Inner joins (equi-joins) with USING clause -- The USING syntax changes the shape of the resulting table -- by including a column in the USING clause only once in the result. -- -- Inner equi-join on specified column SELECT * FROM J1_TBL INNER JOIN J2_TBL USING (i); i | j | t | k ---+---+-------+---- 0 | | zero | 1 | 4 | one | -1 2 | 3 | two | 2 2 | 3 | two | 4 3 | 2 | three | -3 5 | 0 | five | -5 5 | 0 | five | -5 (7 rows) -- Same as above, slightly different syntax SELECT * FROM J1_TBL JOIN J2_TBL USING (i); i | j | t | k ---+---+-------+---- 0 | | zero | 1 | 4 | one | -1 2 | 3 | two | 2 2 | 3 | two | 4 3 | 2 | three | -3 5 | 0 | five | -5 5 | 0 | five | -5 (7 rows) SELECT * FROM J1_TBL t1 (a, b, c) JOIN J2_TBL t2 (a, d) USING (a) ORDER BY a, d; a | b | c | d ---+---+-------+---- 0 | | zero | 1 | 4 | one | -1 2 | 3 | two | 2 2 | 3 | two | 4 3 | 2 | three | -3 5 | 0 | five | -5 5 | 0 | five | -5 (7 rows) SELECT * FROM J1_TBL t1 (a, b, c) JOIN J2_TBL t2 (a, b) USING (b) ORDER BY b, t1.a; b | a | c | a ---+---+-------+--- 0 | 5 | five | 0 | | zero | 2 | 3 | three | 2 4 | 1 | one | 2 (4 rows) -- test join using aliases SELECT * FROM J1_TBL JOIN J2_TBL USING (i) WHERE J1_TBL.t = 'one'; -- ok i | j | t | k ---+---+-----+---- 1 | 4 | one | -1 (1 row) SELECT * FROM J1_TBL JOIN J2_TBL USING (i) AS x WHERE J1_TBL.t = 'one'; -- ok i | j | t | k ---+---+-----+---- 1 | 4 | one | -1 (1 row) SELECT * FROM (J1_TBL JOIN J2_TBL USING (i)) AS x WHERE J1_TBL.t = 'one'; -- error ERROR: invalid reference to FROM-clause entry for table "j1_tbl" LINE 1: ... * FROM (J1_TBL JOIN J2_TBL USING (i)) AS x WHERE J1_TBL.t =... ^ DETAIL: There is an entry for table "j1_tbl", but it cannot be referenced from this part of the query. SELECT * FROM J1_TBL JOIN J2_TBL USING (i) AS x WHERE x.i = 1; -- ok i | j | t | k ---+---+-----+---- 1 | 4 | one | -1 (1 row) SELECT * FROM J1_TBL JOIN J2_TBL USING (i) AS x WHERE x.t = 'one'; -- error ERROR: column x.t does not exist LINE 1: ...CT * FROM J1_TBL JOIN J2_TBL USING (i) AS x WHERE x.t = 'one... ^ SELECT * FROM (J1_TBL JOIN J2_TBL USING (i) AS x) AS xx WHERE x.i = 1; -- error (XXX could use better hint) ERROR: missing FROM-clause entry for table "x" LINE 1: ...ROM (J1_TBL JOIN J2_TBL USING (i) AS x) AS xx WHERE x.i = 1; ^ SELECT * FROM J1_TBL a1 JOIN J2_TBL a2 USING (i) AS a1; -- error ERROR: table name "a1" specified more than once SELECT x.* FROM J1_TBL JOIN J2_TBL USING (i) AS x WHERE J1_TBL.t = 'one'; i --- 1 (1 row) SELECT ROW(x.*) FROM J1_TBL JOIN J2_TBL USING (i) AS x WHERE J1_TBL.t = 'one'; row ----- (1) (1 row) SELECT row_to_json(x.*) FROM J1_TBL JOIN J2_TBL USING (i) AS x WHERE J1_TBL.t = 'one'; row_to_json ------------- {"i":1} (1 row) -- -- NATURAL JOIN -- Inner equi-join on all columns with the same name -- SELECT * FROM J1_TBL NATURAL JOIN J2_TBL; i | j | t | k ---+---+-------+---- 0 | | zero | 1 | 4 | one | -1 2 | 3 | two | 2 2 | 3 | two | 4 3 | 2 | three | -3 5 | 0 | five | -5 5 | 0 | five | -5 (7 rows) SELECT * FROM J1_TBL t1 (a, b, c) NATURAL JOIN J2_TBL t2 (a, d); a | b | c | d ---+---+-------+---- 0 | | zero | 1 | 4 | one | -1 2 | 3 | two | 2 2 | 3 | two | 4 3 | 2 | three | -3 5 | 0 | five | -5 5 | 0 | five | -5 (7 rows) SELECT * FROM J1_TBL t1 (a, b, c) NATURAL JOIN J2_TBL t2 (d, a); a | b | c | d ---+---+------+--- 0 | | zero | 2 | 3 | two | 2 4 | 1 | four | 2 (3 rows) -- mismatch number of columns -- currently, Postgres will fill in with underlying names SELECT * FROM J1_TBL t1 (a, b) NATURAL JOIN J2_TBL t2 (a); a | b | t | k ---+---+-------+---- 0 | | zero | 1 | 4 | one | -1 2 | 3 | two | 2 2 | 3 | two | 4 3 | 2 | three | -3 5 | 0 | five | -5 5 | 0 | five | -5 (7 rows) -- -- Inner joins (equi-joins) -- SELECT * FROM J1_TBL JOIN J2_TBL ON (J1_TBL.i = J2_TBL.i); i | j | t | i | k ---+---+-------+---+---- 0 | | zero | 0 | 1 | 4 | one | 1 | -1 2 | 3 | two | 2 | 2 2 | 3 | two | 2 | 4 3 | 2 | three | 3 | -3 5 | 0 | five | 5 | -5 5 | 0 | five | 5 | -5 (7 rows) SELECT * FROM J1_TBL JOIN J2_TBL ON (J1_TBL.i = J2_TBL.k); i | j | t | i | k ---+---+------+---+--- 0 | | zero | | 0 2 | 3 | two | 2 | 2 4 | 1 | four | 2 | 4 (3 rows) -- -- Non-equi-joins -- SELECT * FROM J1_TBL JOIN J2_TBL ON (J1_TBL.i <= J2_TBL.k); i | j | t | i | k ---+---+-------+---+--- 1 | 4 | one | 2 | 2 2 | 3 | two | 2 | 2 0 | | zero | 2 | 2 1 | 4 | one | 2 | 4 2 | 3 | two | 2 | 4 3 | 2 | three | 2 | 4 4 | 1 | four | 2 | 4 0 | | zero | 2 | 4 0 | | zero | | 0 (9 rows) -- -- Outer joins -- Note that OUTER is a noise word -- SELECT * FROM J1_TBL LEFT OUTER JOIN J2_TBL USING (i) ORDER BY i, k, t; i | j | t | k ---+---+-------+---- 0 | | zero | 1 | 4 | one | -1 2 | 3 | two | 2 2 | 3 | two | 4 3 | 2 | three | -3 4 | 1 | four | 5 | 0 | five | -5 5 | 0 | five | -5 6 | 6 | six | 7 | 7 | seven | 8 | 8 | eight | | | null | | 0 | zero | (13 rows) SELECT * FROM J1_TBL LEFT JOIN J2_TBL USING (i) ORDER BY i, k, t; i | j | t | k ---+---+-------+---- 0 | | zero | 1 | 4 | one | -1 2 | 3 | two | 2 2 | 3 | two | 4 3 | 2 | three | -3 4 | 1 | four | 5 | 0 | five | -5 5 | 0 | five | -5 6 | 6 | six | 7 | 7 | seven | 8 | 8 | eight | | | null | | 0 | zero | (13 rows) SELECT * FROM J1_TBL RIGHT OUTER JOIN J2_TBL USING (i); i | j | t | k ---+---+-------+---- 0 | | zero | 1 | 4 | one | -1 2 | 3 | two | 2 2 | 3 | two | 4 3 | 2 | three | -3 5 | 0 | five | -5 5 | 0 | five | -5 | | | | | | 0 (9 rows) SELECT * FROM J1_TBL RIGHT JOIN J2_TBL USING (i); i | j | t | k ---+---+-------+---- 0 | | zero | 1 | 4 | one | -1 2 | 3 | two | 2 2 | 3 | two | 4 3 | 2 | three | -3 5 | 0 | five | -5 5 | 0 | five | -5 | | | | | | 0 (9 rows) SELECT * FROM J1_TBL FULL OUTER JOIN J2_TBL USING (i) ORDER BY i, k, t; i | j | t | k ---+---+-------+---- 0 | | zero | 1 | 4 | one | -1 2 | 3 | two | 2 2 | 3 | two | 4 3 | 2 | three | -3 4 | 1 | four | 5 | 0 | five | -5 5 | 0 | five | -5 6 | 6 | six | 7 | 7 | seven | 8 | 8 | eight | | | | 0 | | null | | 0 | zero | | | | (15 rows) SELECT * FROM J1_TBL FULL JOIN J2_TBL USING (i) ORDER BY i, k, t; i | j | t | k ---+---+-------+---- 0 | | zero | 1 | 4 | one | -1 2 | 3 | two | 2 2 | 3 | two | 4 3 | 2 | three | -3 4 | 1 | four | 5 | 0 | five | -5 5 | 0 | five | -5 6 | 6 | six | 7 | 7 | seven | 8 | 8 | eight | | | | 0 | | null | | 0 | zero | | | | (15 rows) SELECT * FROM J1_TBL LEFT JOIN J2_TBL USING (i) WHERE (k = 1); i | j | t | k ---+---+---+--- (0 rows) SELECT * FROM J1_TBL LEFT JOIN J2_TBL USING (i) WHERE (i = 1); i | j | t | k ---+---+-----+---- 1 | 4 | one | -1 (1 row) -- -- semijoin selectivity for <> -- explain (costs off) select * from int4_tbl i4, tenk1 a where exists(select * from tenk1 b where a.twothousand = b.twothousand and a.fivethous <> b.fivethous) and i4.f1 = a.tenthous; QUERY PLAN ---------------------------------------------- Hash Semi Join Hash Cond: (a.twothousand = b.twothousand) Join Filter: (a.fivethous <> b.fivethous) -> Hash Join Hash Cond: (a.tenthous = i4.f1) -> Seq Scan on tenk1 a -> Hash -> Seq Scan on int4_tbl i4 -> Hash -> Seq Scan on tenk1 b (10 rows) -- -- More complicated constructs -- -- -- Multiway full join -- CREATE TABLE t1 (name TEXT, n INTEGER); CREATE TABLE t2 (name TEXT, n INTEGER); CREATE TABLE t3 (name TEXT, n INTEGER); INSERT INTO t1 VALUES ( 'bb', 11 ); INSERT INTO t2 VALUES ( 'bb', 12 ); INSERT INTO t2 VALUES ( 'cc', 22 ); INSERT INTO t2 VALUES ( 'ee', 42 ); INSERT INTO t3 VALUES ( 'bb', 13 ); INSERT INTO t3 VALUES ( 'cc', 23 ); INSERT INTO t3 VALUES ( 'dd', 33 ); SELECT * FROM t1 FULL JOIN t2 USING (name) FULL JOIN t3 USING (name); name | n | n | n ------+----+----+---- bb | 11 | 12 | 13 cc | | 22 | 23 dd | | | 33 ee | | 42 | (4 rows) -- -- Test interactions of join syntax and subqueries -- -- Basic cases (we expect planner to pull up the subquery here) SELECT * FROM (SELECT * FROM t2) as s2 INNER JOIN (SELECT * FROM t3) s3 USING (name); name | n | n ------+----+---- bb | 12 | 13 cc | 22 | 23 (2 rows) SELECT * FROM (SELECT * FROM t2) as s2 LEFT JOIN (SELECT * FROM t3) s3 USING (name); name | n | n ------+----+---- bb | 12 | 13 cc | 22 | 23 ee | 42 | (3 rows) SELECT * FROM (SELECT * FROM t2) as s2 FULL JOIN (SELECT * FROM t3) s3 USING (name); name | n | n ------+----+---- bb | 12 | 13 cc | 22 | 23 dd | | 33 ee | 42 | (4 rows) -- Cases with non-nullable expressions in subquery results; -- make sure these go to null as expected SELECT * FROM (SELECT name, n as s2_n, 2 as s2_2 FROM t2) as s2 NATURAL INNER JOIN (SELECT name, n as s3_n, 3 as s3_2 FROM t3) s3; name | s2_n | s2_2 | s3_n | s3_2 ------+------+------+------+------ bb | 12 | 2 | 13 | 3 cc | 22 | 2 | 23 | 3 (2 rows) SELECT * FROM (SELECT name, n as s2_n, 2 as s2_2 FROM t2) as s2 NATURAL LEFT JOIN (SELECT name, n as s3_n, 3 as s3_2 FROM t3) s3; name | s2_n | s2_2 | s3_n | s3_2 ------+------+------+------+------ bb | 12 | 2 | 13 | 3 cc | 22 | 2 | 23 | 3 ee | 42 | 2 | | (3 rows) SELECT * FROM (SELECT name, n as s2_n, 2 as s2_2 FROM t2) as s2 NATURAL FULL JOIN (SELECT name, n as s3_n, 3 as s3_2 FROM t3) s3; name | s2_n | s2_2 | s3_n | s3_2 ------+------+------+------+------ bb | 12 | 2 | 13 | 3 cc | 22 | 2 | 23 | 3 dd | | | 33 | 3 ee | 42 | 2 | | (4 rows) SELECT * FROM (SELECT name, n as s1_n, 1 as s1_1 FROM t1) as s1 NATURAL INNER JOIN (SELECT name, n as s2_n, 2 as s2_2 FROM t2) as s2 NATURAL INNER JOIN (SELECT name, n as s3_n, 3 as s3_2 FROM t3) s3; name | s1_n | s1_1 | s2_n | s2_2 | s3_n | s3_2 ------+------+------+------+------+------+------ bb | 11 | 1 | 12 | 2 | 13 | 3 (1 row) SELECT * FROM (SELECT name, n as s1_n, 1 as s1_1 FROM t1) as s1 NATURAL FULL JOIN (SELECT name, n as s2_n, 2 as s2_2 FROM t2) as s2 NATURAL FULL JOIN (SELECT name, n as s3_n, 3 as s3_2 FROM t3) s3; name | s1_n | s1_1 | s2_n | s2_2 | s3_n | s3_2 ------+------+------+------+------+------+------ bb | 11 | 1 | 12 | 2 | 13 | 3 cc | | | 22 | 2 | 23 | 3 dd | | | | | 33 | 3 ee | | | 42 | 2 | | (4 rows) SELECT * FROM (SELECT name, n as s1_n FROM t1) as s1 NATURAL FULL JOIN (SELECT * FROM (SELECT name, n as s2_n FROM t2) as s2 NATURAL FULL JOIN (SELECT name, n as s3_n FROM t3) as s3 ) ss2; name | s1_n | s2_n | s3_n ------+------+------+------ bb | 11 | 12 | 13 cc | | 22 | 23 dd | | | 33 ee | | 42 | (4 rows) SELECT * FROM (SELECT name, n as s1_n FROM t1) as s1 NATURAL FULL JOIN (SELECT * FROM (SELECT name, n as s2_n, 2 as s2_2 FROM t2) as s2 NATURAL FULL JOIN (SELECT name, n as s3_n FROM t3) as s3 ) ss2; name | s1_n | s2_n | s2_2 | s3_n ------+------+------+------+------ bb | 11 | 12 | 2 | 13 cc | | 22 | 2 | 23 dd | | | | 33 ee | | 42 | 2 | (4 rows) -- Constants as join keys can also be problematic SELECT * FROM (SELECT name, n as s1_n FROM t1) as s1 FULL JOIN (SELECT name, 2 as s2_n FROM t2) as s2 ON (s1_n = s2_n); name | s1_n | name | s2_n ------+------+------+------ | | bb | 2 | | cc | 2 | | ee | 2 bb | 11 | | (4 rows) -- Test for propagation of nullability constraints into sub-joins create temp table x (x1 int, x2 int); insert into x values (1,11); insert into x values (2,22); insert into x values (3,null); insert into x values (4,44); insert into x values (5,null); create temp table y (y1 int, y2 int); insert into y values (1,111); insert into y values (2,222); insert into y values (3,333); insert into y values (4,null); select * from x; x1 | x2 ----+---- 1 | 11 2 | 22 3 | 4 | 44 5 | (5 rows) select * from y; y1 | y2 ----+----- 1 | 111 2 | 222 3 | 333 4 | (4 rows) select * from x left join y on (x1 = y1 and x2 is not null); x1 | x2 | y1 | y2 ----+----+----+----- 1 | 11 | 1 | 111 2 | 22 | 2 | 222 3 | | | 4 | 44 | 4 | 5 | | | (5 rows) select * from x left join y on (x1 = y1 and y2 is not null); x1 | x2 | y1 | y2 ----+----+----+----- 1 | 11 | 1 | 111 2 | 22 | 2 | 222 3 | | 3 | 333 4 | 44 | | 5 | | | (5 rows) select * from (x left join y on (x1 = y1)) left join x xx(xx1,xx2) on (x1 = xx1); x1 | x2 | y1 | y2 | xx1 | xx2 ----+----+----+-----+-----+----- 1 | 11 | 1 | 111 | 1 | 11 2 | 22 | 2 | 222 | 2 | 22 3 | | 3 | 333 | 3 | 4 | 44 | 4 | | 4 | 44 5 | | | | 5 | (5 rows) select * from (x left join y on (x1 = y1)) left join x xx(xx1,xx2) on (x1 = xx1 and x2 is not null); x1 | x2 | y1 | y2 | xx1 | xx2 ----+----+----+-----+-----+----- 1 | 11 | 1 | 111 | 1 | 11 2 | 22 | 2 | 222 | 2 | 22 3 | | 3 | 333 | | 4 | 44 | 4 | | 4 | 44 5 | | | | | (5 rows) select * from (x left join y on (x1 = y1)) left join x xx(xx1,xx2) on (x1 = xx1 and y2 is not null); x1 | x2 | y1 | y2 | xx1 | xx2 ----+----+----+-----+-----+----- 1 | 11 | 1 | 111 | 1 | 11 2 | 22 | 2 | 222 | 2 | 22 3 | | 3 | 333 | 3 | 4 | 44 | 4 | | | 5 | | | | | (5 rows) select * from (x left join y on (x1 = y1)) left join x xx(xx1,xx2) on (x1 = xx1 and xx2 is not null); x1 | x2 | y1 | y2 | xx1 | xx2 ----+----+----+-----+-----+----- 1 | 11 | 1 | 111 | 1 | 11 2 | 22 | 2 | 222 | 2 | 22 3 | | 3 | 333 | | 4 | 44 | 4 | | 4 | 44 5 | | | | | (5 rows) -- these should NOT give the same answers as above select * from (x left join y on (x1 = y1)) left join x xx(xx1,xx2) on (x1 = xx1) where (x2 is not null); x1 | x2 | y1 | y2 | xx1 | xx2 ----+----+----+-----+-----+----- 1 | 11 | 1 | 111 | 1 | 11 2 | 22 | 2 | 222 | 2 | 22 4 | 44 | 4 | | 4 | 44 (3 rows) select * from (x left join y on (x1 = y1)) left join x xx(xx1,xx2) on (x1 = xx1) where (y2 is not null); x1 | x2 | y1 | y2 | xx1 | xx2 ----+----+----+-----+-----+----- 1 | 11 | 1 | 111 | 1 | 11 2 | 22 | 2 | 222 | 2 | 22 3 | | 3 | 333 | 3 | (3 rows) select * from (x left join y on (x1 = y1)) left join x xx(xx1,xx2) on (x1 = xx1) where (xx2 is not null); x1 | x2 | y1 | y2 | xx1 | xx2 ----+----+----+-----+-----+----- 1 | 11 | 1 | 111 | 1 | 11 2 | 22 | 2 | 222 | 2 | 22 4 | 44 | 4 | | 4 | 44 (3 rows) -- -- regression test: check for bug with propagation of implied equality -- to outside an IN -- select count(*) from tenk1 a where unique1 in (select unique1 from tenk1 b join tenk1 c using (unique1) where b.unique2 = 42); count ------- 1 (1 row) -- -- regression test: check for failure to generate a plan with multiple -- degenerate IN clauses -- select count(*) from tenk1 x where x.unique1 in (select a.f1 from int4_tbl a,float8_tbl b where a.f1=b.f1) and x.unique1 = 0 and x.unique1 in (select aa.f1 from int4_tbl aa,float8_tbl bb where aa.f1=bb.f1); count ------- 1 (1 row) -- try that with GEQO too begin; set geqo = on; set geqo_threshold = 2; select count(*) from tenk1 x where x.unique1 in (select a.f1 from int4_tbl a,float8_tbl b where a.f1=b.f1) and x.unique1 = 0 and x.unique1 in (select aa.f1 from int4_tbl aa,float8_tbl bb where aa.f1=bb.f1); count ------- 1 (1 row) rollback; -- -- regression test: be sure we cope with proven-dummy append rels -- explain (costs off) select aa, bb, unique1, unique1 from tenk1 right join b_star on aa = unique1 where bb < bb and bb is null; QUERY PLAN -------------------------- Result One-Time Filter: false (2 rows) select aa, bb, unique1, unique1 from tenk1 right join b_star on aa = unique1 where bb < bb and bb is null; aa | bb | unique1 | unique1 ----+----+---------+--------- (0 rows) -- -- regression test: check handling of empty-FROM subquery underneath outer join -- explain (costs off) select * from int8_tbl i1 left join (int8_tbl i2 join (select 123 as x) ss on i2.q1 = x) on i1.q2 = i2.q2 order by 1, 2; QUERY PLAN ------------------------------------------- Sort Sort Key: i1.q1, i1.q2 -> Hash Left Join Hash Cond: (i1.q2 = i2.q2) -> Seq Scan on int8_tbl i1 -> Hash -> Seq Scan on int8_tbl i2 Filter: (q1 = 123) (8 rows) select * from int8_tbl i1 left join (int8_tbl i2 join (select 123 as x) ss on i2.q1 = x) on i1.q2 = i2.q2 order by 1, 2; q1 | q2 | q1 | q2 | x ------------------+-------------------+-----+------------------+----- 123 | 456 | 123 | 456 | 123 123 | 4567890123456789 | 123 | 4567890123456789 | 123 4567890123456789 | -4567890123456789 | | | 4567890123456789 | 123 | | | 4567890123456789 | 4567890123456789 | 123 | 4567890123456789 | 123 (5 rows) -- -- regression test: check a case where join_clause_is_movable_into() -- used to give an imprecise result, causing an assertion failure -- select count(*) from (select t3.tenthous as x1, coalesce(t1.stringu1, t2.stringu1) as x2 from tenk1 t1 left join tenk1 t2 on t1.unique1 = t2.unique1 join tenk1 t3 on t1.unique2 = t3.unique2) ss, tenk1 t4, tenk1 t5 where t4.thousand = t5.unique1 and ss.x1 = t4.tenthous and ss.x2 = t5.stringu1; count ------- 1000 (1 row) -- -- regression test: check a case where we formerly missed including an EC -- enforcement clause because it was expected to be handled at scan level -- explain (costs off) select a.f1, b.f1, t.thousand, t.tenthous from tenk1 t, (select sum(f1)+1 as f1 from int4_tbl i4a) a, (select sum(f1) as f1 from int4_tbl i4b) b where b.f1 = t.thousand and a.f1 = b.f1 and (a.f1+b.f1+999) = t.tenthous; QUERY PLAN ----------------------------------------------------------------------------------------------------------------- Nested Loop -> Nested Loop Join Filter: ((sum(i4b.f1)) = ((sum(i4a.f1) + 1))) -> Aggregate -> Seq Scan on int4_tbl i4a -> Aggregate -> Seq Scan on int4_tbl i4b -> Index Only Scan using tenk1_thous_tenthous on tenk1 t Index Cond: ((thousand = (sum(i4b.f1))) AND (tenthous = ((((sum(i4a.f1) + 1)) + (sum(i4b.f1))) + 999))) (9 rows) select a.f1, b.f1, t.thousand, t.tenthous from tenk1 t, (select sum(f1)+1 as f1 from int4_tbl i4a) a, (select sum(f1) as f1 from int4_tbl i4b) b where b.f1 = t.thousand and a.f1 = b.f1 and (a.f1+b.f1+999) = t.tenthous; f1 | f1 | thousand | tenthous ----+----+----------+---------- (0 rows) -- -- checks for correct handling of quals in multiway outer joins -- explain (costs off) select t1.f1 from int4_tbl t1, int4_tbl t2 left join int4_tbl t3 on t3.f1 > 0 left join int4_tbl t4 on t3.f1 > 1 where t4.f1 is null; QUERY PLAN ------------------------------------------------------- Nested Loop -> Nested Loop Left Join Filter: (t4.f1 IS NULL) -> Seq Scan on int4_tbl t2 -> Materialize -> Nested Loop Left Join Join Filter: (t3.f1 > 1) -> Seq Scan on int4_tbl t3 Filter: (f1 > 0) -> Materialize -> Seq Scan on int4_tbl t4 -> Seq Scan on int4_tbl t1 (12 rows) select t1.f1 from int4_tbl t1, int4_tbl t2 left join int4_tbl t3 on t3.f1 > 0 left join int4_tbl t4 on t3.f1 > 1 where t4.f1 is null; f1 ---- (0 rows) explain (costs off) select * from int4_tbl t1 left join int4_tbl t2 on true left join int4_tbl t3 on t2.f1 > 0 left join int4_tbl t4 on t3.f1 > 0; QUERY PLAN ------------------------------------------------------- Nested Loop Left Join -> Seq Scan on int4_tbl t1 -> Materialize -> Nested Loop Left Join Join Filter: (t3.f1 > 0) -> Nested Loop Left Join Join Filter: (t2.f1 > 0) -> Seq Scan on int4_tbl t2 -> Materialize -> Seq Scan on int4_tbl t3 -> Materialize -> Seq Scan on int4_tbl t4 (12 rows) explain (costs off) select * from onek t1 left join onek t2 on t1.unique1 = t2.unique1 left join onek t3 on t2.unique1 != t3.unique1 left join onek t4 on t3.unique1 = t4.unique1; QUERY PLAN ---------------------------------------------------- Nested Loop Left Join Join Filter: (t2.unique1 <> t3.unique1) -> Hash Left Join Hash Cond: (t1.unique1 = t2.unique1) -> Seq Scan on onek t1 -> Hash -> Seq Scan on onek t2 -> Materialize -> Hash Left Join Hash Cond: (t3.unique1 = t4.unique1) -> Seq Scan on onek t3 -> Hash -> Seq Scan on onek t4 (13 rows) explain (costs off) select * from int4_tbl t1 left join (select now() from int4_tbl t2 left join int4_tbl t3 on t2.f1 = t3.f1 left join int4_tbl t4 on t3.f1 = t4.f1) s on true inner join int4_tbl t5 on true; QUERY PLAN ------------------------------------------------------------- Nested Loop -> Nested Loop Left Join -> Seq Scan on int4_tbl t1 -> Materialize -> Hash Left Join Hash Cond: (t3.f1 = t4.f1) -> Hash Left Join Hash Cond: (t2.f1 = t3.f1) -> Seq Scan on int4_tbl t2 -> Hash -> Seq Scan on int4_tbl t3 -> Hash -> Seq Scan on int4_tbl t4 -> Materialize -> Seq Scan on int4_tbl t5 (15 rows) explain (costs off) select * from int4_tbl t1 left join int4_tbl t2 on true left join int4_tbl t3 on true left join int4_tbl t4 on t2.f1 = t3.f1; QUERY PLAN ------------------------------------------------- Nested Loop Left Join Join Filter: (t2.f1 = t3.f1) -> Nested Loop Left Join -> Nested Loop Left Join -> Seq Scan on int4_tbl t1 -> Materialize -> Seq Scan on int4_tbl t2 -> Materialize -> Seq Scan on int4_tbl t3 -> Materialize -> Seq Scan on int4_tbl t4 (11 rows) explain (costs off) select * from int4_tbl t1 left join int4_tbl t2 on true left join int4_tbl t3 on t2.f1 = t3.f1 left join int4_tbl t4 on t3.f1 != t4.f1; QUERY PLAN ------------------------------------------------------- Nested Loop Left Join -> Seq Scan on int4_tbl t1 -> Materialize -> Nested Loop Left Join Join Filter: (t3.f1 <> t4.f1) -> Hash Left Join Hash Cond: (t2.f1 = t3.f1) -> Seq Scan on int4_tbl t2 -> Hash -> Seq Scan on int4_tbl t3 -> Materialize -> Seq Scan on int4_tbl t4 (12 rows) explain (costs off) select * from int4_tbl t1 left join (int4_tbl t2 left join int4_tbl t3 on t2.f1 > 0) on t2.f1 > 1 left join int4_tbl t4 on t2.f1 > 2 and t3.f1 > 3 where t1.f1 = coalesce(t2.f1, 1); QUERY PLAN ---------------------------------------------------- Nested Loop Left Join Join Filter: ((t2.f1 > 2) AND (t3.f1 > 3)) -> Nested Loop Left Join Join Filter: (t2.f1 > 0) -> Nested Loop Left Join Filter: (t1.f1 = COALESCE(t2.f1, 1)) -> Seq Scan on int4_tbl t1 -> Materialize -> Seq Scan on int4_tbl t2 Filter: (f1 > 1) -> Seq Scan on int4_tbl t3 -> Materialize -> Seq Scan on int4_tbl t4 (13 rows) explain (costs off) select * from int4_tbl t1 left join ((select t2.f1 from int4_tbl t2 left join int4_tbl t3 on t2.f1 > 0 where t3.f1 is null) s left join tenk1 t4 on s.f1 > 1) on s.f1 = t1.f1; QUERY PLAN ------------------------------------------------- Nested Loop Left Join Join Filter: (t2.f1 > 1) -> Hash Right Join Hash Cond: (t2.f1 = t1.f1) -> Nested Loop Left Join Join Filter: (t2.f1 > 0) Filter: (t3.f1 IS NULL) -> Seq Scan on int4_tbl t2 -> Materialize -> Seq Scan on int4_tbl t3 -> Hash -> Seq Scan on int4_tbl t1 -> Seq Scan on tenk1 t4 (13 rows) explain (costs off) select * from onek t1 left join onek t2 on t1.unique1 = t2.unique1 left join onek t3 on t2.unique1 = t3.unique1 left join onek t4 on t3.unique1 = t4.unique1 and t2.unique2 = t4.unique2; QUERY PLAN ------------------------------------------------------------------------ Hash Left Join Hash Cond: ((t3.unique1 = t4.unique1) AND (t2.unique2 = t4.unique2)) -> Hash Left Join Hash Cond: (t2.unique1 = t3.unique1) -> Hash Left Join Hash Cond: (t1.unique1 = t2.unique1) -> Seq Scan on onek t1 -> Hash -> Seq Scan on onek t2 -> Hash -> Seq Scan on onek t3 -> Hash -> Seq Scan on onek t4 (13 rows) explain (costs off) select * from int8_tbl t1 left join (int8_tbl t2 left join int8_tbl t3 full join int8_tbl t4 on false on false) left join int8_tbl t5 on t2.q1 = t5.q1 on t2.q2 = 123; QUERY PLAN -------------------------------------------------- Nested Loop Left Join -> Seq Scan on int8_tbl t1 -> Materialize -> Nested Loop Left Join Join Filter: (t2.q1 = t5.q1) -> Nested Loop Left Join Join Filter: false -> Seq Scan on int8_tbl t2 Filter: (q2 = 123) -> Result One-Time Filter: false -> Seq Scan on int8_tbl t5 (12 rows) -- -- check a case where we formerly got confused by conflicting sort orders -- in redundant merge join path keys -- explain (costs off) select * from j1_tbl full join (select * from j2_tbl order by j2_tbl.i desc, j2_tbl.k asc) j2_tbl on j1_tbl.i = j2_tbl.i and j1_tbl.i = j2_tbl.k; QUERY PLAN ----------------------------------------------------------------- Merge Full Join Merge Cond: ((j2_tbl.i = j1_tbl.i) AND (j2_tbl.k = j1_tbl.i)) -> Sort Sort Key: j2_tbl.i DESC, j2_tbl.k -> Seq Scan on j2_tbl -> Sort Sort Key: j1_tbl.i DESC -> Seq Scan on j1_tbl (8 rows) select * from j1_tbl full join (select * from j2_tbl order by j2_tbl.i desc, j2_tbl.k asc) j2_tbl on j1_tbl.i = j2_tbl.i and j1_tbl.i = j2_tbl.k; i | j | t | i | k ---+---+-------+---+---- | | | | 0 | | | | | 0 | zero | | | | null | | 8 | 8 | eight | | 7 | 7 | seven | | 6 | 6 | six | | | | | 5 | -5 | | | 5 | -5 5 | 0 | five | | 4 | 1 | four | | | | | 3 | -3 3 | 2 | three | | 2 | 3 | two | 2 | 2 | | | 2 | 4 | | | 1 | -1 | | | 0 | 1 | 4 | one | | 0 | | zero | | (19 rows) -- -- a different check for handling of redundant sort keys in merge joins -- explain (costs off) select count(*) from (select * from tenk1 x order by x.thousand, x.twothousand, x.fivethous) x left join (select * from tenk1 y order by y.unique2) y on x.thousand = y.unique2 and x.twothousand = y.hundred and x.fivethous = y.unique2; QUERY PLAN ---------------------------------------------------------------------------------- Aggregate -> Merge Left Join Merge Cond: (x.thousand = y.unique2) Join Filter: ((x.twothousand = y.hundred) AND (x.fivethous = y.unique2)) -> Sort Sort Key: x.thousand, x.twothousand, x.fivethous -> Seq Scan on tenk1 x -> Materialize -> Index Scan using tenk1_unique2 on tenk1 y (9 rows) select count(*) from (select * from tenk1 x order by x.thousand, x.twothousand, x.fivethous) x left join (select * from tenk1 y order by y.unique2) y on x.thousand = y.unique2 and x.twothousand = y.hundred and x.fivethous = y.unique2; count ------- 10000 (1 row) set enable_hashjoin = 0; set enable_nestloop = 0; set enable_hashagg = 0; -- -- Check that we use the pathkeys from a prefix of the group by / order by -- clause for the join pathkeys when that prefix covers all join quals. We -- expect this to lead to an incremental sort for the group by / order by. -- explain (costs off) select x.thousand, x.twothousand, count(*) from tenk1 x inner join tenk1 y on x.thousand = y.thousand group by x.thousand, x.twothousand order by x.thousand desc, x.twothousand; QUERY PLAN ---------------------------------------------------------------------------------- GroupAggregate Group Key: x.thousand, x.twothousand -> Incremental Sort Sort Key: x.thousand DESC, x.twothousand Presorted Key: x.thousand -> Merge Join Merge Cond: (y.thousand = x.thousand) -> Index Only Scan Backward using tenk1_thous_tenthous on tenk1 y -> Sort Sort Key: x.thousand DESC -> Seq Scan on tenk1 x (11 rows) reset enable_hashagg; reset enable_nestloop; reset enable_hashjoin; -- -- Clean up -- DROP TABLE t1; DROP TABLE t2; DROP TABLE t3; DROP TABLE J1_TBL; DROP TABLE J2_TBL; -- Both DELETE and UPDATE allow the specification of additional tables -- to "join" against to determine which rows should be modified. CREATE TEMP TABLE t1 (a int, b int); CREATE TEMP TABLE t2 (a int, b int); CREATE TEMP TABLE t3 (x int, y int); INSERT INTO t1 VALUES (5, 10); INSERT INTO t1 VALUES (15, 20); INSERT INTO t1 VALUES (100, 100); INSERT INTO t1 VALUES (200, 1000); INSERT INTO t2 VALUES (200, 2000); INSERT INTO t3 VALUES (5, 20); INSERT INTO t3 VALUES (6, 7); INSERT INTO t3 VALUES (7, 8); INSERT INTO t3 VALUES (500, 100); DELETE FROM t3 USING t1 table1 WHERE t3.x = table1.a; SELECT * FROM t3; x | y -----+----- 6 | 7 7 | 8 500 | 100 (3 rows) DELETE FROM t3 USING t1 JOIN t2 USING (a) WHERE t3.x > t1.a; SELECT * FROM t3; x | y ---+--- 6 | 7 7 | 8 (2 rows) DELETE FROM t3 USING t3 t3_other WHERE t3.x = t3_other.x AND t3.y = t3_other.y; SELECT * FROM t3; x | y ---+--- (0 rows) -- Test join against inheritance tree create temp table t2a () inherits (t2); insert into t2a values (200, 2001); select * from t1 left join t2 on (t1.a = t2.a); a | b | a | b -----+------+-----+------ 5 | 10 | | 15 | 20 | | 100 | 100 | | 200 | 1000 | 200 | 2000 200 | 1000 | 200 | 2001 (5 rows) -- Test matching of column name with wrong alias select t1.x from t1 join t3 on (t1.a = t3.x); ERROR: column t1.x does not exist LINE 1: select t1.x from t1 join t3 on (t1.a = t3.x); ^ HINT: Perhaps you meant to reference the column "t3.x". -- Test matching of locking clause with wrong alias select t1.*, t2.*, unnamed_join.* from t1 join t2 on (t1.a = t2.a), t3 as unnamed_join for update of unnamed_join; a | b | a | b | x | y ---+---+---+---+---+--- (0 rows) select foo.*, unnamed_join.* from t1 join t2 using (a) as foo, t3 as unnamed_join for update of unnamed_join; a | x | y ---+---+--- (0 rows) select foo.*, unnamed_join.* from t1 join t2 using (a) as foo, t3 as unnamed_join for update of foo; ERROR: FOR UPDATE cannot be applied to a join LINE 3: for update of foo; ^ select bar.*, unnamed_join.* from (t1 join t2 using (a) as foo) as bar, t3 as unnamed_join for update of foo; ERROR: relation "foo" in FOR UPDATE clause not found in FROM clause LINE 3: for update of foo; ^ select bar.*, unnamed_join.* from (t1 join t2 using (a) as foo) as bar, t3 as unnamed_join for update of bar; ERROR: FOR UPDATE cannot be applied to a join LINE 3: for update of bar; ^ -- -- regression test for 8.1 merge right join bug -- CREATE TEMP TABLE tt1 ( tt1_id int4, joincol int4 ); INSERT INTO tt1 VALUES (1, 11); INSERT INTO tt1 VALUES (2, NULL); CREATE TEMP TABLE tt2 ( tt2_id int4, joincol int4 ); INSERT INTO tt2 VALUES (21, 11); INSERT INTO tt2 VALUES (22, 11); set enable_hashjoin to off; set enable_nestloop to off; -- these should give the same results select tt1.*, tt2.* from tt1 left join tt2 on tt1.joincol = tt2.joincol; tt1_id | joincol | tt2_id | joincol --------+---------+--------+--------- 1 | 11 | 21 | 11 1 | 11 | 22 | 11 2 | | | (3 rows) select tt1.*, tt2.* from tt2 right join tt1 on tt1.joincol = tt2.joincol; tt1_id | joincol | tt2_id | joincol --------+---------+--------+--------- 1 | 11 | 21 | 11 1 | 11 | 22 | 11 2 | | | (3 rows) reset enable_hashjoin; reset enable_nestloop; -- -- regression test for bug #13908 (hash join with skew tuples & nbatch increase) -- set work_mem to '64kB'; set enable_mergejoin to off; set enable_memoize to off; explain (costs off) select count(*) from tenk1 a, tenk1 b where a.hundred = b.thousand and (b.fivethous % 10) < 10; QUERY PLAN ------------------------------------------------------------ Aggregate -> Hash Join Hash Cond: (a.hundred = b.thousand) -> Index Only Scan using tenk1_hundred on tenk1 a -> Hash -> Seq Scan on tenk1 b Filter: ((fivethous % 10) < 10) (7 rows) select count(*) from tenk1 a, tenk1 b where a.hundred = b.thousand and (b.fivethous % 10) < 10; count -------- 100000 (1 row) reset work_mem; reset enable_mergejoin; reset enable_memoize; -- -- regression test for 8.2 bug with improper re-ordering of left joins -- create temp table tt3(f1 int, f2 text); insert into tt3 select x, repeat('xyzzy', 100) from generate_series(1,10000) x; analyze tt3; create temp table tt4(f1 int); insert into tt4 values (0),(1),(9999); analyze tt4; set enable_nestloop to off; EXPLAIN (COSTS OFF) SELECT a.f1 FROM tt4 a LEFT JOIN ( SELECT b.f1 FROM tt3 b LEFT JOIN tt3 c ON (b.f1 = c.f1) WHERE COALESCE(c.f1, 0) = 0 ) AS d ON (a.f1 = d.f1) WHERE COALESCE(d.f1, 0) = 0 ORDER BY 1; QUERY PLAN ----------------------------------------------- Sort Sort Key: a.f1 -> Hash Right Join Hash Cond: (b.f1 = a.f1) Filter: (COALESCE(b.f1, 0) = 0) -> Hash Left Join Hash Cond: (b.f1 = c.f1) Filter: (COALESCE(c.f1, 0) = 0) -> Seq Scan on tt3 b -> Hash -> Seq Scan on tt3 c -> Hash -> Seq Scan on tt4 a (13 rows) SELECT a.f1 FROM tt4 a LEFT JOIN ( SELECT b.f1 FROM tt3 b LEFT JOIN tt3 c ON (b.f1 = c.f1) WHERE COALESCE(c.f1, 0) = 0 ) AS d ON (a.f1 = d.f1) WHERE COALESCE(d.f1, 0) = 0 ORDER BY 1; f1 ------ 0 1 9999 (3 rows) reset enable_nestloop; -- -- basic semijoin and antijoin recognition tests -- explain (costs off) select a.* from tenk1 a where unique1 in (select unique2 from tenk1 b); QUERY PLAN ------------------------------------------------------------ Hash Semi Join Hash Cond: (a.unique1 = b.unique2) -> Seq Scan on tenk1 a -> Hash -> Index Only Scan using tenk1_unique2 on tenk1 b (5 rows) -- sadly, this is not an antijoin explain (costs off) select a.* from tenk1 a where unique1 not in (select unique2 from tenk1 b); QUERY PLAN -------------------------------------------------------- Seq Scan on tenk1 a Filter: (NOT (hashed SubPlan 1)) SubPlan 1 -> Index Only Scan using tenk1_unique2 on tenk1 b (4 rows) explain (costs off) select a.* from tenk1 a where exists (select 1 from tenk1 b where a.unique1 = b.unique2); QUERY PLAN ------------------------------------------------------------ Hash Semi Join Hash Cond: (a.unique1 = b.unique2) -> Seq Scan on tenk1 a -> Hash -> Index Only Scan using tenk1_unique2 on tenk1 b (5 rows) explain (costs off) select a.* from tenk1 a where not exists (select 1 from tenk1 b where a.unique1 = b.unique2); QUERY PLAN ------------------------------------------------------------ Hash Anti Join Hash Cond: (a.unique1 = b.unique2) -> Seq Scan on tenk1 a -> Hash -> Index Only Scan using tenk1_unique2 on tenk1 b (5 rows) explain (costs off) select a.* from tenk1 a left join tenk1 b on a.unique1 = b.unique2 where b.unique2 is null; QUERY PLAN ------------------------------------------------------------ Hash Anti Join Hash Cond: (a.unique1 = b.unique2) -> Seq Scan on tenk1 a -> Hash -> Index Only Scan using tenk1_unique2 on tenk1 b (5 rows) -- -- regression test for proper handling of outer joins within antijoins -- create temp table tt4x(c1 int, c2 int, c3 int); explain (costs off) select * from tt4x t1 where not exists ( select 1 from tt4x t2 left join tt4x t3 on t2.c3 = t3.c1 left join ( select t5.c1 as c1 from tt4x t4 left join tt4x t5 on t4.c2 = t5.c1 ) a1 on t3.c2 = a1.c1 where t1.c1 = t2.c2 ); QUERY PLAN --------------------------------------------------------- Hash Anti Join Hash Cond: (t1.c1 = t2.c2) -> Seq Scan on tt4x t1 -> Hash -> Merge Right Join Merge Cond: (t5.c1 = t3.c2) -> Merge Join Merge Cond: (t4.c2 = t5.c1) -> Sort Sort Key: t4.c2 -> Seq Scan on tt4x t4 -> Sort Sort Key: t5.c1 -> Seq Scan on tt4x t5 -> Sort Sort Key: t3.c2 -> Merge Left Join Merge Cond: (t2.c3 = t3.c1) -> Sort Sort Key: t2.c3 -> Seq Scan on tt4x t2 -> Sort Sort Key: t3.c1 -> Seq Scan on tt4x t3 (24 rows) -- -- regression test for problems of the sort depicted in bug #3494 -- create temp table tt5(f1 int, f2 int); create temp table tt6(f1 int, f2 int); insert into tt5 values(1, 10); insert into tt5 values(1, 11); insert into tt6 values(1, 9); insert into tt6 values(1, 2); insert into tt6 values(2, 9); select * from tt5,tt6 where tt5.f1 = tt6.f1 and tt5.f1 = tt5.f2 - tt6.f2; f1 | f2 | f1 | f2 ----+----+----+---- 1 | 10 | 1 | 9 (1 row) -- -- regression test for problems of the sort depicted in bug #3588 -- create temp table xx (pkxx int); create temp table yy (pkyy int, pkxx int); insert into xx values (1); insert into xx values (2); insert into xx values (3); insert into yy values (101, 1); insert into yy values (201, 2); insert into yy values (301, NULL); select yy.pkyy as yy_pkyy, yy.pkxx as yy_pkxx, yya.pkyy as yya_pkyy, xxa.pkxx as xxa_pkxx, xxb.pkxx as xxb_pkxx from yy left join (SELECT * FROM yy where pkyy = 101) as yya ON yy.pkyy = yya.pkyy left join xx xxa on yya.pkxx = xxa.pkxx left join xx xxb on coalesce (xxa.pkxx, 1) = xxb.pkxx; yy_pkyy | yy_pkxx | yya_pkyy | xxa_pkxx | xxb_pkxx ---------+---------+----------+----------+---------- 101 | 1 | 101 | 1 | 1 201 | 2 | | | 1 301 | | | | 1 (3 rows) -- -- regression test for improper pushing of constants across outer-join clauses -- (as seen in early 8.2.x releases) -- create temp table zt1 (f1 int primary key); create temp table zt2 (f2 int primary key); create temp table zt3 (f3 int primary key); insert into zt1 values(53); insert into zt2 values(53); select * from zt2 left join zt3 on (f2 = f3) left join zt1 on (f3 = f1) where f2 = 53; f2 | f3 | f1 ----+----+---- 53 | | (1 row) create temp view zv1 as select *,'dummy'::text AS junk from zt1; select * from zt2 left join zt3 on (f2 = f3) left join zv1 on (f3 = f1) where f2 = 53; f2 | f3 | f1 | junk ----+----+----+------ 53 | | | (1 row) -- -- regression test for improper extraction of OR indexqual conditions -- (as seen in early 8.3.x releases) -- select a.unique2, a.ten, b.tenthous, b.unique2, b.hundred from tenk1 a left join tenk1 b on a.unique2 = b.tenthous where a.unique1 = 42 and ((b.unique2 is null and a.ten = 2) or b.hundred = 3); unique2 | ten | tenthous | unique2 | hundred ---------+-----+----------+---------+--------- (0 rows) -- -- test proper positioning of one-time quals in EXISTS (8.4devel bug) -- prepare foo(bool) as select count(*) from tenk1 a left join tenk1 b on (a.unique2 = b.unique1 and exists (select 1 from tenk1 c where c.thousand = b.unique2 and $1)); execute foo(true); count ------- 10000 (1 row) execute foo(false); count ------- 10000 (1 row) -- -- test for sane behavior with noncanonical merge clauses, per bug #4926 -- begin; set enable_mergejoin = 1; set enable_hashjoin = 0; set enable_nestloop = 0; create temp table a (i integer); create temp table b (x integer, y integer); select * from a left join b on i = x and i = y and x = i; i | x | y ---+---+--- (0 rows) rollback; -- -- test handling of merge clauses using record_ops -- begin; create type mycomptype as (id int, v bigint); create temp table tidv (idv mycomptype); create index on tidv (idv); explain (costs off) select a.idv, b.idv from tidv a, tidv b where a.idv = b.idv; QUERY PLAN ---------------------------------------------------------- Merge Join Merge Cond: (a.idv = b.idv) -> Index Only Scan using tidv_idv_idx on tidv a -> Materialize -> Index Only Scan using tidv_idv_idx on tidv b (5 rows) set enable_mergejoin = 0; set enable_hashjoin = 0; explain (costs off) select a.idv, b.idv from tidv a, tidv b where a.idv = b.idv; QUERY PLAN ---------------------------------------------------- Nested Loop -> Seq Scan on tidv a -> Index Only Scan using tidv_idv_idx on tidv b Index Cond: (idv = a.idv) (4 rows) rollback; -- -- test NULL behavior of whole-row Vars, per bug #5025 -- select t1.q2, count(t2.*) from int8_tbl t1 left join int8_tbl t2 on (t1.q2 = t2.q1) group by t1.q2 order by 1; q2 | count -------------------+------- -4567890123456789 | 0 123 | 2 456 | 0 4567890123456789 | 6 (4 rows) select t1.q2, count(t2.*) from int8_tbl t1 left join (select * from int8_tbl) t2 on (t1.q2 = t2.q1) group by t1.q2 order by 1; q2 | count -------------------+------- -4567890123456789 | 0 123 | 2 456 | 0 4567890123456789 | 6 (4 rows) select t1.q2, count(t2.*) from int8_tbl t1 left join (select * from int8_tbl offset 0) t2 on (t1.q2 = t2.q1) group by t1.q2 order by 1; q2 | count -------------------+------- -4567890123456789 | 0 123 | 2 456 | 0 4567890123456789 | 6 (4 rows) select t1.q2, count(t2.*) from int8_tbl t1 left join (select q1, case when q2=1 then 1 else q2 end as q2 from int8_tbl) t2 on (t1.q2 = t2.q1) group by t1.q2 order by 1; q2 | count -------------------+------- -4567890123456789 | 0 123 | 2 456 | 0 4567890123456789 | 6 (4 rows) -- -- test incorrect failure to NULL pulled-up subexpressions -- begin; create temp table a ( code char not null, constraint a_pk primary key (code) ); create temp table b ( a char not null, num integer not null, constraint b_pk primary key (a, num) ); create temp table c ( name char not null, a char, constraint c_pk primary key (name) ); insert into a (code) values ('p'); insert into a (code) values ('q'); insert into b (a, num) values ('p', 1); insert into b (a, num) values ('p', 2); insert into c (name, a) values ('A', 'p'); insert into c (name, a) values ('B', 'q'); insert into c (name, a) values ('C', null); select c.name, ss.code, ss.b_cnt, ss.const from c left join (select a.code, coalesce(b_grp.cnt, 0) as b_cnt, -1 as const from a left join (select count(1) as cnt, b.a from b group by b.a) as b_grp on a.code = b_grp.a ) as ss on (c.a = ss.code) order by c.name; name | code | b_cnt | const ------+------+-------+------- A | p | 2 | -1 B | q | 0 | -1 C | | | (3 rows) rollback; -- -- test incorrect handling of placeholders that only appear in targetlists, -- per bug #6154 -- SELECT * FROM ( SELECT 1 as key1 ) sub1 LEFT JOIN ( SELECT sub3.key3, sub4.value2, COALESCE(sub4.value2, 66) as value3 FROM ( SELECT 1 as key3 ) sub3 LEFT JOIN ( SELECT sub5.key5, COALESCE(sub6.value1, 1) as value2 FROM ( SELECT 1 as key5 ) sub5 LEFT JOIN ( SELECT 2 as key6, 42 as value1 ) sub6 ON sub5.key5 = sub6.key6 ) sub4 ON sub4.key5 = sub3.key3 ) sub2 ON sub1.key1 = sub2.key3; key1 | key3 | value2 | value3 ------+------+--------+-------- 1 | 1 | 1 | 1 (1 row) -- test the path using join aliases, too SELECT * FROM ( SELECT 1 as key1 ) sub1 LEFT JOIN ( SELECT sub3.key3, value2, COALESCE(value2, 66) as value3 FROM ( SELECT 1 as key3 ) sub3 LEFT JOIN ( SELECT sub5.key5, COALESCE(sub6.value1, 1) as value2 FROM ( SELECT 1 as key5 ) sub5 LEFT JOIN ( SELECT 2 as key6, 42 as value1 ) sub6 ON sub5.key5 = sub6.key6 ) sub4 ON sub4.key5 = sub3.key3 ) sub2 ON sub1.key1 = sub2.key3; key1 | key3 | value2 | value3 ------+------+--------+-------- 1 | 1 | 1 | 1 (1 row) -- -- test case where a PlaceHolderVar is used as a nestloop parameter -- EXPLAIN (COSTS OFF) SELECT qq, unique1 FROM ( SELECT COALESCE(q1, 0) AS qq FROM int8_tbl a ) AS ss1 FULL OUTER JOIN ( SELECT COALESCE(q2, -1) AS qq FROM int8_tbl b ) AS ss2 USING (qq) INNER JOIN tenk1 c ON qq = unique2; QUERY PLAN --------------------------------------------------------------------------------------------------------- Nested Loop -> Hash Full Join Hash Cond: ((COALESCE(a.q1, '0'::bigint)) = (COALESCE(b.q2, '-1'::bigint))) -> Seq Scan on int8_tbl a -> Hash -> Seq Scan on int8_tbl b -> Index Scan using tenk1_unique2 on tenk1 c Index Cond: (unique2 = COALESCE((COALESCE(a.q1, '0'::bigint)), (COALESCE(b.q2, '-1'::bigint)))) (8 rows) SELECT qq, unique1 FROM ( SELECT COALESCE(q1, 0) AS qq FROM int8_tbl a ) AS ss1 FULL OUTER JOIN ( SELECT COALESCE(q2, -1) AS qq FROM int8_tbl b ) AS ss2 USING (qq) INNER JOIN tenk1 c ON qq = unique2; qq | unique1 -----+--------- 123 | 4596 123 | 4596 456 | 7318 (3 rows) -- -- nested nestloops can require nested PlaceHolderVars -- create temp table nt1 ( id int primary key, a1 boolean, a2 boolean ); create temp table nt2 ( id int primary key, nt1_id int, b1 boolean, b2 boolean, foreign key (nt1_id) references nt1(id) ); create temp table nt3 ( id int primary key, nt2_id int, c1 boolean, foreign key (nt2_id) references nt2(id) ); insert into nt1 values (1,true,true); insert into nt1 values (2,true,false); insert into nt1 values (3,false,false); insert into nt2 values (1,1,true,true); insert into nt2 values (2,2,true,false); insert into nt2 values (3,3,false,false); insert into nt3 values (1,1,true); insert into nt3 values (2,2,false); insert into nt3 values (3,3,true); explain (costs off) select nt3.id from nt3 as nt3 left join (select nt2.*, (nt2.b1 and ss1.a3) AS b3 from nt2 as nt2 left join (select nt1.*, (nt1.id is not null) as a3 from nt1) as ss1 on ss1.id = nt2.nt1_id ) as ss2 on ss2.id = nt3.nt2_id where nt3.id = 1 and ss2.b3; QUERY PLAN ----------------------------------------------- Nested Loop -> Nested Loop -> Index Scan using nt3_pkey on nt3 Index Cond: (id = 1) -> Index Scan using nt2_pkey on nt2 Index Cond: (id = nt3.nt2_id) -> Index Only Scan using nt1_pkey on nt1 Index Cond: (id = nt2.nt1_id) Filter: (nt2.b1 AND (id IS NOT NULL)) (9 rows) select nt3.id from nt3 as nt3 left join (select nt2.*, (nt2.b1 and ss1.a3) AS b3 from nt2 as nt2 left join (select nt1.*, (nt1.id is not null) as a3 from nt1) as ss1 on ss1.id = nt2.nt1_id ) as ss2 on ss2.id = nt3.nt2_id where nt3.id = 1 and ss2.b3; id ---- 1 (1 row) -- -- test case where a PlaceHolderVar is propagated into a subquery -- explain (costs off) select * from int8_tbl t1 left join (select q1 as x, 42 as y from int8_tbl t2) ss on t1.q2 = ss.x where 1 = (select 1 from int8_tbl t3 where ss.y is not null limit 1) order by 1,2; QUERY PLAN ----------------------------------------------------------- Sort Sort Key: t1.q1, t1.q2 -> Hash Left Join Hash Cond: (t1.q2 = t2.q1) Filter: (1 = (SubPlan 1)) -> Seq Scan on int8_tbl t1 -> Hash -> Seq Scan on int8_tbl t2 SubPlan 1 -> Limit -> Result One-Time Filter: ((42) IS NOT NULL) -> Seq Scan on int8_tbl t3 (13 rows) select * from int8_tbl t1 left join (select q1 as x, 42 as y from int8_tbl t2) ss on t1.q2 = ss.x where 1 = (select 1 from int8_tbl t3 where ss.y is not null limit 1) order by 1,2; q1 | q2 | x | y ------------------+------------------+------------------+---- 123 | 4567890123456789 | 4567890123456789 | 42 123 | 4567890123456789 | 4567890123456789 | 42 123 | 4567890123456789 | 4567890123456789 | 42 4567890123456789 | 123 | 123 | 42 4567890123456789 | 123 | 123 | 42 4567890123456789 | 4567890123456789 | 4567890123456789 | 42 4567890123456789 | 4567890123456789 | 4567890123456789 | 42 4567890123456789 | 4567890123456789 | 4567890123456789 | 42 (8 rows) -- -- variant where a PlaceHolderVar is needed at a join, but not above the join -- explain (costs off) select * from int4_tbl as i41, lateral (select 1 as x from (select i41.f1 as lat, i42.f1 as loc from int8_tbl as i81, int4_tbl as i42) as ss1 right join int4_tbl as i43 on (i43.f1 > 1) where ss1.loc = ss1.lat) as ss2 where i41.f1 > 0; QUERY PLAN -------------------------------------------------- Nested Loop -> Nested Loop -> Seq Scan on int4_tbl i41 Filter: (f1 > 0) -> Nested Loop Join Filter: (i42.f1 = i41.f1) -> Seq Scan on int8_tbl i81 -> Materialize -> Seq Scan on int4_tbl i42 -> Materialize -> Seq Scan on int4_tbl i43 Filter: (f1 > 1) (12 rows) select * from int4_tbl as i41, lateral (select 1 as x from (select i41.f1 as lat, i42.f1 as loc from int8_tbl as i81, int4_tbl as i42) as ss1 right join int4_tbl as i43 on (i43.f1 > 1) where ss1.loc = ss1.lat) as ss2 where i41.f1 > 0; f1 | x ------------+--- 123456 | 1 123456 | 1 123456 | 1 123456 | 1 123456 | 1 123456 | 1 123456 | 1 123456 | 1 123456 | 1 123456 | 1 2147483647 | 1 2147483647 | 1 2147483647 | 1 2147483647 | 1 2147483647 | 1 2147483647 | 1 2147483647 | 1 2147483647 | 1 2147483647 | 1 2147483647 | 1 (20 rows) -- -- test the corner cases FULL JOIN ON TRUE and FULL JOIN ON FALSE -- select * from int4_tbl a full join int4_tbl b on true; f1 | f1 -------------+------------- 0 | 0 0 | 123456 0 | -123456 0 | 2147483647 0 | -2147483647 123456 | 0 123456 | 123456 123456 | -123456 123456 | 2147483647 123456 | -2147483647 -123456 | 0 -123456 | 123456 -123456 | -123456 -123456 | 2147483647 -123456 | -2147483647 2147483647 | 0 2147483647 | 123456 2147483647 | -123456 2147483647 | 2147483647 2147483647 | -2147483647 -2147483647 | 0 -2147483647 | 123456 -2147483647 | -123456 -2147483647 | 2147483647 -2147483647 | -2147483647 (25 rows) select * from int4_tbl a full join int4_tbl b on false; f1 | f1 -------------+------------- | 0 | 123456 | -123456 | 2147483647 | -2147483647 0 | 123456 | -123456 | 2147483647 | -2147483647 | (10 rows) -- -- test for ability to use a cartesian join when necessary -- create temp table q1 as select 1 as q1; create temp table q2 as select 0 as q2; analyze q1; analyze q2; explain (costs off) select * from tenk1 join int4_tbl on f1 = twothousand, q1, q2 where q1 = thousand or q2 = thousand; QUERY PLAN ------------------------------------------------------------------------ Hash Join Hash Cond: (tenk1.twothousand = int4_tbl.f1) -> Nested Loop -> Nested Loop -> Seq Scan on q1 -> Seq Scan on q2 -> Bitmap Heap Scan on tenk1 Recheck Cond: ((q1.q1 = thousand) OR (q2.q2 = thousand)) -> BitmapOr -> Bitmap Index Scan on tenk1_thous_tenthous Index Cond: (thousand = q1.q1) -> Bitmap Index Scan on tenk1_thous_tenthous Index Cond: (thousand = q2.q2) -> Hash -> Seq Scan on int4_tbl (15 rows) explain (costs off) select * from tenk1 join int4_tbl on f1 = twothousand, q1, q2 where thousand = (q1 + q2); QUERY PLAN -------------------------------------------------------------- Hash Join Hash Cond: (tenk1.twothousand = int4_tbl.f1) -> Nested Loop -> Nested Loop -> Seq Scan on q1 -> Seq Scan on q2 -> Bitmap Heap Scan on tenk1 Recheck Cond: (thousand = (q1.q1 + q2.q2)) -> Bitmap Index Scan on tenk1_thous_tenthous Index Cond: (thousand = (q1.q1 + q2.q2)) -> Hash -> Seq Scan on int4_tbl (12 rows) -- -- test ability to generate a suitable plan for a star-schema query -- explain (costs off) select * from tenk1, int8_tbl a, int8_tbl b where thousand = a.q1 and tenthous = b.q1 and a.q2 = 1 and b.q2 = 2; QUERY PLAN --------------------------------------------------------------------- Nested Loop -> Seq Scan on int8_tbl b Filter: (q2 = 2) -> Nested Loop -> Seq Scan on int8_tbl a Filter: (q2 = 1) -> Index Scan using tenk1_thous_tenthous on tenk1 Index Cond: ((thousand = a.q1) AND (tenthous = b.q1)) (8 rows) -- -- test a corner case in which we shouldn't apply the star-schema optimization -- explain (costs off) select t1.unique2, t1.stringu1, t2.unique1, t2.stringu2 from tenk1 t1 inner join int4_tbl i1 left join (select v1.x2, v2.y1, 11 AS d1 from (select 1,0 from onerow) v1(x1,x2) left join (select 3,1 from onerow) v2(y1,y2) on v1.x1 = v2.y2) subq1 on (i1.f1 = subq1.x2) on (t1.unique2 = subq1.d1) left join tenk1 t2 on (subq1.y1 = t2.unique1) where t1.unique2 < 42 and t1.stringu1 > t2.stringu2; QUERY PLAN ----------------------------------------------------------------------- Nested Loop -> Nested Loop Join Filter: (t1.stringu1 > t2.stringu2) -> Nested Loop -> Nested Loop -> Seq Scan on onerow -> Seq Scan on onerow onerow_1 -> Index Scan using tenk1_unique2 on tenk1 t1 Index Cond: ((unique2 = (11)) AND (unique2 < 42)) -> Index Scan using tenk1_unique1 on tenk1 t2 Index Cond: (unique1 = (3)) -> Seq Scan on int4_tbl i1 Filter: (f1 = 0) (13 rows) select t1.unique2, t1.stringu1, t2.unique1, t2.stringu2 from tenk1 t1 inner join int4_tbl i1 left join (select v1.x2, v2.y1, 11 AS d1 from (select 1,0 from onerow) v1(x1,x2) left join (select 3,1 from onerow) v2(y1,y2) on v1.x1 = v2.y2) subq1 on (i1.f1 = subq1.x2) on (t1.unique2 = subq1.d1) left join tenk1 t2 on (subq1.y1 = t2.unique1) where t1.unique2 < 42 and t1.stringu1 > t2.stringu2; unique2 | stringu1 | unique1 | stringu2 ---------+----------+---------+---------- 11 | WFAAAA | 3 | LKIAAA (1 row) -- variant that isn't quite a star-schema case select ss1.d1 from tenk1 as t1 inner join tenk1 as t2 on t1.tenthous = t2.ten inner join int8_tbl as i8 left join int4_tbl as i4 inner join (select 64::information_schema.cardinal_number as d1 from tenk1 t3, lateral (select abs(t3.unique1) + random()) ss0(x) where t3.fivethous < 0) as ss1 on i4.f1 = ss1.d1 on i8.q1 = i4.f1 on t1.tenthous = ss1.d1 where t1.unique1 < i4.f1; d1 ---- (0 rows) -- this variant is foldable by the remove-useless-RESULT-RTEs code explain (costs off) select t1.unique2, t1.stringu1, t2.unique1, t2.stringu2 from tenk1 t1 inner join int4_tbl i1 left join (select v1.x2, v2.y1, 11 AS d1 from (values(1,0)) v1(x1,x2) left join (values(3,1)) v2(y1,y2) on v1.x1 = v2.y2) subq1 on (i1.f1 = subq1.x2) on (t1.unique2 = subq1.d1) left join tenk1 t2 on (subq1.y1 = t2.unique1) where t1.unique2 < 42 and t1.stringu1 > t2.stringu2; QUERY PLAN ----------------------------------------------------------------- Nested Loop Join Filter: (t1.stringu1 > t2.stringu2) -> Nested Loop -> Seq Scan on int4_tbl i1 Filter: (f1 = 0) -> Index Scan using tenk1_unique2 on tenk1 t1 Index Cond: ((unique2 = (11)) AND (unique2 < 42)) -> Index Scan using tenk1_unique1 on tenk1 t2 Index Cond: (unique1 = (3)) (9 rows) select t1.unique2, t1.stringu1, t2.unique1, t2.stringu2 from tenk1 t1 inner join int4_tbl i1 left join (select v1.x2, v2.y1, 11 AS d1 from (values(1,0)) v1(x1,x2) left join (values(3,1)) v2(y1,y2) on v1.x1 = v2.y2) subq1 on (i1.f1 = subq1.x2) on (t1.unique2 = subq1.d1) left join tenk1 t2 on (subq1.y1 = t2.unique1) where t1.unique2 < 42 and t1.stringu1 > t2.stringu2; unique2 | stringu1 | unique1 | stringu2 ---------+----------+---------+---------- 11 | WFAAAA | 3 | LKIAAA (1 row) -- Here's a variant that we can't fold too aggressively, though, -- or we end up with noplace to evaluate the lateral PHV explain (verbose, costs off) select * from (select 1 as x) ss1 left join (select 2 as y) ss2 on (true), lateral (select ss2.y as z limit 1) ss3; QUERY PLAN --------------------------- Nested Loop Output: 1, (2), ((2)) -> Result Output: 2 -> Limit Output: ((2)) -> Result Output: (2) (8 rows) select * from (select 1 as x) ss1 left join (select 2 as y) ss2 on (true), lateral (select ss2.y as z limit 1) ss3; x | y | z ---+---+--- 1 | 2 | 2 (1 row) -- Test proper handling of appendrel PHVs during useless-RTE removal explain (costs off) select * from (select 0 as z) as t1 left join (select true as a) as t2 on true, lateral (select true as b union all select a as b) as t3 where b; QUERY PLAN --------------------------------------- Nested Loop -> Result -> Append -> Result -> Result One-Time Filter: (true) (6 rows) select * from (select 0 as z) as t1 left join (select true as a) as t2 on true, lateral (select true as b union all select a as b) as t3 where b; z | a | b ---+---+--- 0 | t | t 0 | t | t (2 rows) -- Test PHV in a semijoin qual, which confused useless-RTE removal (bug #17700) explain (verbose, costs off) with ctetable as not materialized ( select 1 as f1 ) select * from ctetable c1 where f1 in ( select c3.f1 from ctetable c2 full join ctetable c3 on true ); QUERY PLAN ---------------------------- Result Output: 1 One-Time Filter: (1 = 1) (3 rows) with ctetable as not materialized ( select 1 as f1 ) select * from ctetable c1 where f1 in ( select c3.f1 from ctetable c2 full join ctetable c3 on true ); f1 ---- 1 (1 row) -- Test PHV that winds up in a Result node, despite having nonempty nullingrels explain (verbose, costs off) select table_catalog, table_name from int4_tbl t1 inner join (int8_tbl t2 left join information_schema.column_udt_usage on null) on null; QUERY PLAN ------------------------------------------------------------------------------------------------------------------- Result Output: (current_database())::information_schema.sql_identifier, (c.relname)::information_schema.sql_identifier One-Time Filter: false (3 rows) -- Test handling of qual pushdown to appendrel members with non-Var outputs explain (verbose, costs off) select * from int4_tbl left join ( select text 'foo' union all select text 'bar' ) ss(x) on true where ss.x is null; QUERY PLAN ----------------------------------------- Nested Loop Left Join Output: int4_tbl.f1, ('foo'::text) Filter: (('foo'::text) IS NULL) -> Seq Scan on public.int4_tbl Output: int4_tbl.f1 -> Materialize Output: ('foo'::text) -> Append -> Result Output: 'foo'::text -> Result Output: 'bar'::text (12 rows) -- -- test inlining of immutable functions -- create function f_immutable_int4(i integer) returns integer as $$ begin return i; end; $$ language plpgsql immutable; -- check optimization of function scan with join explain (costs off) select unique1 from tenk1, (select * from f_immutable_int4(1) x) x where x = unique1; QUERY PLAN ---------------------------------------------- Index Only Scan using tenk1_unique1 on tenk1 Index Cond: (unique1 = 1) (2 rows) explain (verbose, costs off) select unique1, x.* from tenk1, (select *, random() from f_immutable_int4(1) x) x where x = unique1; QUERY PLAN ----------------------------------------------------------- Nested Loop Output: tenk1.unique1, (1), (random()) -> Result Output: 1, random() -> Index Only Scan using tenk1_unique1 on public.tenk1 Output: tenk1.unique1 Index Cond: (tenk1.unique1 = (1)) (7 rows) explain (costs off) select unique1 from tenk1, f_immutable_int4(1) x where x = unique1; QUERY PLAN ---------------------------------------------- Index Only Scan using tenk1_unique1 on tenk1 Index Cond: (unique1 = 1) (2 rows) explain (costs off) select unique1 from tenk1, lateral f_immutable_int4(1) x where x = unique1; QUERY PLAN ---------------------------------------------- Index Only Scan using tenk1_unique1 on tenk1 Index Cond: (unique1 = 1) (2 rows) explain (costs off) select unique1 from tenk1, lateral f_immutable_int4(1) x where x in (select 17); QUERY PLAN -------------------------- Result One-Time Filter: false (2 rows) explain (costs off) select unique1, x from tenk1 join f_immutable_int4(1) x on unique1 = x; QUERY PLAN ---------------------------------------------- Index Only Scan using tenk1_unique1 on tenk1 Index Cond: (unique1 = 1) (2 rows) explain (costs off) select unique1, x from tenk1 left join f_immutable_int4(1) x on unique1 = x; QUERY PLAN ---------------------------------------------------- Nested Loop Left Join Join Filter: (tenk1.unique1 = 1) -> Index Only Scan using tenk1_unique1 on tenk1 -> Materialize -> Result (5 rows) explain (costs off) select unique1, x from tenk1 right join f_immutable_int4(1) x on unique1 = x; QUERY PLAN ---------------------------------------------------- Nested Loop Left Join -> Result -> Index Only Scan using tenk1_unique1 on tenk1 Index Cond: (unique1 = 1) (4 rows) explain (costs off) select unique1, x from tenk1 full join f_immutable_int4(1) x on unique1 = x; QUERY PLAN ---------------------------------------------------- Merge Full Join Merge Cond: (tenk1.unique1 = (1)) -> Index Only Scan using tenk1_unique1 on tenk1 -> Sort Sort Key: (1) -> Result (6 rows) -- check that pullup of a const function allows further const-folding explain (costs off) select unique1 from tenk1, f_immutable_int4(1) x where x = 42; QUERY PLAN -------------------------- Result One-Time Filter: false (2 rows) -- test inlining of immutable functions with PlaceHolderVars explain (costs off) select nt3.id from nt3 as nt3 left join (select nt2.*, (nt2.b1 or i4 = 42) AS b3 from nt2 as nt2 left join f_immutable_int4(0) i4 on i4 = nt2.nt1_id ) as ss2 on ss2.id = nt3.nt2_id where nt3.id = 1 and ss2.b3; QUERY PLAN ---------------------------------------------- Nested Loop Left Join Filter: ((nt2.b1 OR ((0) = 42))) -> Index Scan using nt3_pkey on nt3 Index Cond: (id = 1) -> Nested Loop Left Join Join Filter: (0 = nt2.nt1_id) -> Index Scan using nt2_pkey on nt2 Index Cond: (id = nt3.nt2_id) -> Result (9 rows) drop function f_immutable_int4(int); -- test inlining when function returns composite create function mki8(bigint, bigint) returns int8_tbl as $$select row($1,$2)::int8_tbl$$ language sql; create function mki4(int) returns int4_tbl as $$select row($1)::int4_tbl$$ language sql; explain (verbose, costs off) select * from mki8(1,2); QUERY PLAN ------------------------------------ Function Scan on mki8 Output: q1, q2 Function Call: '(1,2)'::int8_tbl (3 rows) select * from mki8(1,2); q1 | q2 ----+---- 1 | 2 (1 row) explain (verbose, costs off) select * from mki4(42); QUERY PLAN ----------------------------------- Function Scan on mki4 Output: f1 Function Call: '(42)'::int4_tbl (3 rows) select * from mki4(42); f1 ---- 42 (1 row) drop function mki8(bigint, bigint); drop function mki4(int); -- -- test extraction of restriction OR clauses from join OR clause -- (we used to only do this for indexable clauses) -- explain (costs off) select * from tenk1 a join tenk1 b on (a.unique1 = 1 and b.unique1 = 2) or (a.unique2 = 3 and b.hundred = 4); QUERY PLAN ------------------------------------------------------------------------------------------------- Nested Loop Join Filter: (((a.unique1 = 1) AND (b.unique1 = 2)) OR ((a.unique2 = 3) AND (b.hundred = 4))) -> Bitmap Heap Scan on tenk1 b Recheck Cond: ((unique1 = 2) OR (hundred = 4)) -> BitmapOr -> Bitmap Index Scan on tenk1_unique1 Index Cond: (unique1 = 2) -> Bitmap Index Scan on tenk1_hundred Index Cond: (hundred = 4) -> Materialize -> Bitmap Heap Scan on tenk1 a Recheck Cond: ((unique1 = 1) OR (unique2 = 3)) -> BitmapOr -> Bitmap Index Scan on tenk1_unique1 Index Cond: (unique1 = 1) -> Bitmap Index Scan on tenk1_unique2 Index Cond: (unique2 = 3) (17 rows) explain (costs off) select * from tenk1 a join tenk1 b on (a.unique1 = 1 and b.unique1 = 2) or (a.unique2 = 3 and b.ten = 4); QUERY PLAN --------------------------------------------------------------------------------------------- Nested Loop Join Filter: (((a.unique1 = 1) AND (b.unique1 = 2)) OR ((a.unique2 = 3) AND (b.ten = 4))) -> Seq Scan on tenk1 b Filter: ((unique1 = 2) OR (ten = 4)) -> Materialize -> Bitmap Heap Scan on tenk1 a Recheck Cond: ((unique1 = 1) OR (unique2 = 3)) -> BitmapOr -> Bitmap Index Scan on tenk1_unique1 Index Cond: (unique1 = 1) -> Bitmap Index Scan on tenk1_unique2 Index Cond: (unique2 = 3) (12 rows) explain (costs off) select * from tenk1 a join tenk1 b on (a.unique1 = 1 and b.unique1 = 2) or ((a.unique2 = 3 or a.unique2 = 7) and b.hundred = 4); QUERY PLAN ---------------------------------------------------------------------------------------------------------------------- Nested Loop Join Filter: (((a.unique1 = 1) AND (b.unique1 = 2)) OR (((a.unique2 = 3) OR (a.unique2 = 7)) AND (b.hundred = 4))) -> Bitmap Heap Scan on tenk1 b Recheck Cond: ((unique1 = 2) OR (hundred = 4)) -> BitmapOr -> Bitmap Index Scan on tenk1_unique1 Index Cond: (unique1 = 2) -> Bitmap Index Scan on tenk1_hundred Index Cond: (hundred = 4) -> Materialize -> Bitmap Heap Scan on tenk1 a Recheck Cond: ((unique1 = 1) OR (unique2 = 3) OR (unique2 = 7)) -> BitmapOr -> Bitmap Index Scan on tenk1_unique1 Index Cond: (unique1 = 1) -> Bitmap Index Scan on tenk1_unique2 Index Cond: (unique2 = 3) -> Bitmap Index Scan on tenk1_unique2 Index Cond: (unique2 = 7) (19 rows) -- -- test placement of movable quals in a parameterized join tree -- explain (costs off) select * from tenk1 t1 left join (tenk1 t2 join tenk1 t3 on t2.thousand = t3.unique2) on t1.hundred = t2.hundred and t1.ten = t3.ten where t1.unique1 = 1; QUERY PLAN -------------------------------------------------------- Nested Loop Left Join -> Index Scan using tenk1_unique1 on tenk1 t1 Index Cond: (unique1 = 1) -> Nested Loop Join Filter: (t1.ten = t3.ten) -> Bitmap Heap Scan on tenk1 t2 Recheck Cond: (t1.hundred = hundred) -> Bitmap Index Scan on tenk1_hundred Index Cond: (hundred = t1.hundred) -> Index Scan using tenk1_unique2 on tenk1 t3 Index Cond: (unique2 = t2.thousand) (11 rows) explain (costs off) select * from tenk1 t1 left join (tenk1 t2 join tenk1 t3 on t2.thousand = t3.unique2) on t1.hundred = t2.hundred and t1.ten + t2.ten = t3.ten where t1.unique1 = 1; QUERY PLAN -------------------------------------------------------- Nested Loop Left Join -> Index Scan using tenk1_unique1 on tenk1 t1 Index Cond: (unique1 = 1) -> Nested Loop Join Filter: ((t1.ten + t2.ten) = t3.ten) -> Bitmap Heap Scan on tenk1 t2 Recheck Cond: (t1.hundred = hundred) -> Bitmap Index Scan on tenk1_hundred Index Cond: (hundred = t1.hundred) -> Index Scan using tenk1_unique2 on tenk1 t3 Index Cond: (unique2 = t2.thousand) (11 rows) explain (costs off) select count(*) from tenk1 a join tenk1 b on a.unique1 = b.unique2 left join tenk1 c on a.unique2 = b.unique1 and c.thousand = a.thousand join int4_tbl on b.thousand = f1; QUERY PLAN ------------------------------------------------------------------------- Aggregate -> Nested Loop Left Join Join Filter: (a.unique2 = b.unique1) -> Nested Loop -> Nested Loop -> Seq Scan on int4_tbl -> Bitmap Heap Scan on tenk1 b Recheck Cond: (thousand = int4_tbl.f1) -> Bitmap Index Scan on tenk1_thous_tenthous Index Cond: (thousand = int4_tbl.f1) -> Index Scan using tenk1_unique1 on tenk1 a Index Cond: (unique1 = b.unique2) -> Index Only Scan using tenk1_thous_tenthous on tenk1 c Index Cond: (thousand = a.thousand) (14 rows) select count(*) from tenk1 a join tenk1 b on a.unique1 = b.unique2 left join tenk1 c on a.unique2 = b.unique1 and c.thousand = a.thousand join int4_tbl on b.thousand = f1; count ------- 10 (1 row) explain (costs off) select b.unique1 from tenk1 a join tenk1 b on a.unique1 = b.unique2 left join tenk1 c on b.unique1 = 42 and c.thousand = a.thousand join int4_tbl i1 on b.thousand = f1 right join int4_tbl i2 on i2.f1 = b.tenthous order by 1; QUERY PLAN ----------------------------------------------------------------------------------------- Sort Sort Key: b.unique1 -> Nested Loop Left Join -> Seq Scan on int4_tbl i2 -> Nested Loop Left Join Join Filter: (b.unique1 = 42) -> Nested Loop -> Nested Loop -> Seq Scan on int4_tbl i1 -> Index Scan using tenk1_thous_tenthous on tenk1 b Index Cond: ((thousand = i1.f1) AND (tenthous = i2.f1)) -> Index Scan using tenk1_unique1 on tenk1 a Index Cond: (unique1 = b.unique2) -> Index Only Scan using tenk1_thous_tenthous on tenk1 c Index Cond: (thousand = a.thousand) (15 rows) select b.unique1 from tenk1 a join tenk1 b on a.unique1 = b.unique2 left join tenk1 c on b.unique1 = 42 and c.thousand = a.thousand join int4_tbl i1 on b.thousand = f1 right join int4_tbl i2 on i2.f1 = b.tenthous order by 1; unique1 --------- 0 (5 rows) explain (costs off) select * from ( select unique1, q1, coalesce(unique1, -1) + q1 as fault from int8_tbl left join tenk1 on (q2 = unique2) ) ss where fault = 122 order by fault; QUERY PLAN -------------------------------------------------------------------------- Nested Loop Left Join Filter: ((COALESCE(tenk1.unique1, '-1'::integer) + int8_tbl.q1) = 122) -> Seq Scan on int8_tbl -> Index Scan using tenk1_unique2 on tenk1 Index Cond: (unique2 = int8_tbl.q2) (5 rows) select * from ( select unique1, q1, coalesce(unique1, -1) + q1 as fault from int8_tbl left join tenk1 on (q2 = unique2) ) ss where fault = 122 order by fault; unique1 | q1 | fault ---------+-----+------- | 123 | 122 (1 row) explain (costs off) select * from (values (1, array[10,20]), (2, array[20,30])) as v1(v1x,v1ys) left join (values (1, 10), (2, 20)) as v2(v2x,v2y) on v2x = v1x left join unnest(v1ys) as u1(u1y) on u1y = v2y; QUERY PLAN ------------------------------------------------------------- Nested Loop Left Join -> Values Scan on "*VALUES*" -> Hash Right Join Hash Cond: (u1.u1y = "*VALUES*_1".column2) Filter: ("*VALUES*_1".column1 = "*VALUES*".column1) -> Function Scan on unnest u1 -> Hash -> Values Scan on "*VALUES*_1" (8 rows) select * from (values (1, array[10,20]), (2, array[20,30])) as v1(v1x,v1ys) left join (values (1, 10), (2, 20)) as v2(v2x,v2y) on v2x = v1x left join unnest(v1ys) as u1(u1y) on u1y = v2y; v1x | v1ys | v2x | v2y | u1y -----+---------+-----+-----+----- 1 | {10,20} | 1 | 10 | 10 2 | {20,30} | 2 | 20 | 20 (2 rows) -- -- test handling of potential equivalence clauses above outer joins -- explain (costs off) select q1, unique2, thousand, hundred from int8_tbl a left join tenk1 b on q1 = unique2 where coalesce(thousand,123) = q1 and q1 = coalesce(hundred,123); QUERY PLAN ---------------------------------------------------------------------------------------------------------- Nested Loop Left Join Filter: ((COALESCE(b.thousand, 123) = COALESCE(b.hundred, 123)) AND (a.q1 = COALESCE(b.hundred, 123))) -> Seq Scan on int8_tbl a -> Index Scan using tenk1_unique2 on tenk1 b Index Cond: (unique2 = a.q1) (5 rows) select q1, unique2, thousand, hundred from int8_tbl a left join tenk1 b on q1 = unique2 where coalesce(thousand,123) = q1 and q1 = coalesce(hundred,123); q1 | unique2 | thousand | hundred ----+---------+----------+--------- (0 rows) explain (costs off) select f1, unique2, case when unique2 is null then f1 else 0 end from int4_tbl a left join tenk1 b on f1 = unique2 where (case when unique2 is null then f1 else 0 end) = 0; QUERY PLAN -------------------------------------------------------------------- Nested Loop Left Join Filter: (CASE WHEN (b.unique2 IS NULL) THEN a.f1 ELSE 0 END = 0) -> Seq Scan on int4_tbl a -> Index Only Scan using tenk1_unique2 on tenk1 b Index Cond: (unique2 = a.f1) (5 rows) select f1, unique2, case when unique2 is null then f1 else 0 end from int4_tbl a left join tenk1 b on f1 = unique2 where (case when unique2 is null then f1 else 0 end) = 0; f1 | unique2 | case ----+---------+------ 0 | 0 | 0 (1 row) -- -- another case with equivalence clauses above outer joins (bug #8591) -- explain (costs off) select a.unique1, b.unique1, c.unique1, coalesce(b.twothousand, a.twothousand) from tenk1 a left join tenk1 b on b.thousand = a.unique1 left join tenk1 c on c.unique2 = coalesce(b.twothousand, a.twothousand) where a.unique2 < 10 and coalesce(b.twothousand, a.twothousand) = 44; QUERY PLAN --------------------------------------------------------------- Nested Loop Left Join -> Nested Loop Left Join Filter: (COALESCE(b.twothousand, a.twothousand) = 44) -> Index Scan using tenk1_unique2 on tenk1 a Index Cond: (unique2 < 10) -> Bitmap Heap Scan on tenk1 b Recheck Cond: (thousand = a.unique1) -> Bitmap Index Scan on tenk1_thous_tenthous Index Cond: (thousand = a.unique1) -> Index Scan using tenk1_unique2 on tenk1 c Index Cond: (unique2 = 44) (11 rows) select a.unique1, b.unique1, c.unique1, coalesce(b.twothousand, a.twothousand) from tenk1 a left join tenk1 b on b.thousand = a.unique1 left join tenk1 c on c.unique2 = coalesce(b.twothousand, a.twothousand) where a.unique2 < 10 and coalesce(b.twothousand, a.twothousand) = 44; unique1 | unique1 | unique1 | coalesce ---------+---------+---------+---------- (0 rows) -- related case explain (costs off) select * from int8_tbl t1 left join int8_tbl t2 on t1.q2 = t2.q1, lateral (select * from int8_tbl t3 where t2.q1 = t2.q2) ss; QUERY PLAN ------------------------------------------- Nested Loop -> Hash Left Join Hash Cond: (t1.q2 = t2.q1) Filter: (t2.q1 = t2.q2) -> Seq Scan on int8_tbl t1 -> Hash -> Seq Scan on int8_tbl t2 -> Seq Scan on int8_tbl t3 (8 rows) select * from int8_tbl t1 left join int8_tbl t2 on t1.q2 = t2.q1, lateral (select * from int8_tbl t3 where t2.q1 = t2.q2) ss; q1 | q2 | q1 | q2 | q1 | q2 ------------------+------------------+------------------+------------------+------------------+------------------- 123 | 4567890123456789 | 4567890123456789 | 4567890123456789 | 123 | 456 123 | 4567890123456789 | 4567890123456789 | 4567890123456789 | 123 | 4567890123456789 123 | 4567890123456789 | 4567890123456789 | 4567890123456789 | 4567890123456789 | 123 123 | 4567890123456789 | 4567890123456789 | 4567890123456789 | 4567890123456789 | 4567890123456789 123 | 4567890123456789 | 4567890123456789 | 4567890123456789 | 4567890123456789 | -4567890123456789 4567890123456789 | 4567890123456789 | 4567890123456789 | 4567890123456789 | 123 | 456 4567890123456789 | 4567890123456789 | 4567890123456789 | 4567890123456789 | 123 | 4567890123456789 4567890123456789 | 4567890123456789 | 4567890123456789 | 4567890123456789 | 4567890123456789 | 123 4567890123456789 | 4567890123456789 | 4567890123456789 | 4567890123456789 | 4567890123456789 | 4567890123456789 4567890123456789 | 4567890123456789 | 4567890123456789 | 4567890123456789 | 4567890123456789 | -4567890123456789 (10 rows) -- -- check handling of join aliases when flattening multiple levels of subquery -- explain (verbose, costs off) select foo1.join_key as foo1_id, foo3.join_key AS foo3_id, bug_field from (values (0),(1)) foo1(join_key) left join (select join_key, bug_field from (select ss1.join_key, ss1.bug_field from (select f1 as join_key, 666 as bug_field from int4_tbl i1) ss1 ) foo2 left join (select unique2 as join_key from tenk1 i2) ss2 using (join_key) ) foo3 using (join_key); QUERY PLAN -------------------------------------------------------------------------- Nested Loop Left Join Output: "*VALUES*".column1, i1.f1, (666) Join Filter: ("*VALUES*".column1 = i1.f1) -> Values Scan on "*VALUES*" Output: "*VALUES*".column1 -> Materialize Output: i1.f1, (666) -> Nested Loop Left Join Output: i1.f1, 666 -> Seq Scan on public.int4_tbl i1 Output: i1.f1 -> Index Only Scan using tenk1_unique2 on public.tenk1 i2 Output: i2.unique2 Index Cond: (i2.unique2 = i1.f1) (14 rows) select foo1.join_key as foo1_id, foo3.join_key AS foo3_id, bug_field from (values (0),(1)) foo1(join_key) left join (select join_key, bug_field from (select ss1.join_key, ss1.bug_field from (select f1 as join_key, 666 as bug_field from int4_tbl i1) ss1 ) foo2 left join (select unique2 as join_key from tenk1 i2) ss2 using (join_key) ) foo3 using (join_key); foo1_id | foo3_id | bug_field ---------+---------+----------- 0 | 0 | 666 1 | | (2 rows) -- -- check handling of a variable-free join alias -- explain (verbose, costs off) select * from int4_tbl i0 left join ( (select *, 123 as x from int4_tbl i1) ss1 left join (select *, q2 as x from int8_tbl i2) ss2 using (x) ) ss0 on (i0.f1 = ss0.f1) order by i0.f1, x; QUERY PLAN ------------------------------------------------------------- Sort Output: i0.f1, ('123'::bigint), i1.f1, i2.q1, i2.q2 Sort Key: i0.f1, ('123'::bigint) -> Hash Right Join Output: i0.f1, ('123'::bigint), i1.f1, i2.q1, i2.q2 Hash Cond: (i1.f1 = i0.f1) -> Nested Loop Left Join Output: i1.f1, i2.q1, i2.q2, '123'::bigint -> Seq Scan on public.int4_tbl i1 Output: i1.f1 -> Materialize Output: i2.q1, i2.q2 -> Seq Scan on public.int8_tbl i2 Output: i2.q1, i2.q2 Filter: (123 = i2.q2) -> Hash Output: i0.f1 -> Seq Scan on public.int4_tbl i0 Output: i0.f1 (19 rows) select * from int4_tbl i0 left join ( (select *, 123 as x from int4_tbl i1) ss1 left join (select *, q2 as x from int8_tbl i2) ss2 using (x) ) ss0 on (i0.f1 = ss0.f1) order by i0.f1, x; f1 | x | f1 | q1 | q2 -------------+-----+-------------+------------------+----- -2147483647 | 123 | -2147483647 | 4567890123456789 | 123 -123456 | 123 | -123456 | 4567890123456789 | 123 0 | 123 | 0 | 4567890123456789 | 123 123456 | 123 | 123456 | 4567890123456789 | 123 2147483647 | 123 | 2147483647 | 4567890123456789 | 123 (5 rows) -- -- test successful handling of nested outer joins with degenerate join quals -- explain (verbose, costs off) select t1.* from text_tbl t1 left join (select *, '***'::text as d1 from int8_tbl i8b1) b1 left join int8_tbl i8 left join (select *, null::int as d2 from int8_tbl i8b2) b2 on (i8.q1 = b2.q1) on (b2.d2 = b1.q2) on (t1.f1 = b1.d1) left join int4_tbl i4 on (i8.q2 = i4.f1); QUERY PLAN ---------------------------------------------------------------------- Hash Left Join Output: t1.f1 Hash Cond: (i8.q2 = i4.f1) -> Nested Loop Left Join Output: t1.f1, i8.q2 Join Filter: (t1.f1 = '***'::text) -> Seq Scan on public.text_tbl t1 Output: t1.f1 -> Materialize Output: i8.q2 -> Hash Right Join Output: i8.q2 Hash Cond: ((NULL::integer) = i8b1.q2) -> Hash Join Output: i8.q2, (NULL::integer) Hash Cond: (i8.q1 = i8b2.q1) -> Seq Scan on public.int8_tbl i8 Output: i8.q1, i8.q2 -> Hash Output: i8b2.q1, (NULL::integer) -> Seq Scan on public.int8_tbl i8b2 Output: i8b2.q1, NULL::integer -> Hash Output: i8b1.q2 -> Seq Scan on public.int8_tbl i8b1 Output: i8b1.q2 -> Hash Output: i4.f1 -> Seq Scan on public.int4_tbl i4 Output: i4.f1 (30 rows) select t1.* from text_tbl t1 left join (select *, '***'::text as d1 from int8_tbl i8b1) b1 left join int8_tbl i8 left join (select *, null::int as d2 from int8_tbl i8b2) b2 on (i8.q1 = b2.q1) on (b2.d2 = b1.q2) on (t1.f1 = b1.d1) left join int4_tbl i4 on (i8.q2 = i4.f1); f1 ------------------- doh! hi de ho neighbor (2 rows) explain (verbose, costs off) select t1.* from text_tbl t1 left join (select *, '***'::text as d1 from int8_tbl i8b1) b1 left join int8_tbl i8 left join (select *, null::int as d2 from int8_tbl i8b2, int4_tbl i4b2) b2 on (i8.q1 = b2.q1) on (b2.d2 = b1.q2) on (t1.f1 = b1.d1) left join int4_tbl i4 on (i8.q2 = i4.f1); QUERY PLAN ---------------------------------------------------------------------------- Hash Left Join Output: t1.f1 Hash Cond: (i8.q2 = i4.f1) -> Nested Loop Left Join Output: t1.f1, i8.q2 Join Filter: (t1.f1 = '***'::text) -> Seq Scan on public.text_tbl t1 Output: t1.f1 -> Materialize Output: i8.q2 -> Hash Right Join Output: i8.q2 Hash Cond: ((NULL::integer) = i8b1.q2) -> Hash Right Join Output: i8.q2, (NULL::integer) Hash Cond: (i8b2.q1 = i8.q1) -> Nested Loop Output: i8b2.q1, NULL::integer -> Seq Scan on public.int8_tbl i8b2 Output: i8b2.q1, i8b2.q2 -> Materialize -> Seq Scan on public.int4_tbl i4b2 -> Hash Output: i8.q1, i8.q2 -> Seq Scan on public.int8_tbl i8 Output: i8.q1, i8.q2 -> Hash Output: i8b1.q2 -> Seq Scan on public.int8_tbl i8b1 Output: i8b1.q2 -> Hash Output: i4.f1 -> Seq Scan on public.int4_tbl i4 Output: i4.f1 (34 rows) select t1.* from text_tbl t1 left join (select *, '***'::text as d1 from int8_tbl i8b1) b1 left join int8_tbl i8 left join (select *, null::int as d2 from int8_tbl i8b2, int4_tbl i4b2) b2 on (i8.q1 = b2.q1) on (b2.d2 = b1.q2) on (t1.f1 = b1.d1) left join int4_tbl i4 on (i8.q2 = i4.f1); f1 ------------------- doh! hi de ho neighbor (2 rows) explain (verbose, costs off) select t1.* from text_tbl t1 left join (select *, '***'::text as d1 from int8_tbl i8b1) b1 left join int8_tbl i8 left join (select *, null::int as d2 from int8_tbl i8b2, int4_tbl i4b2 where q1 = f1) b2 on (i8.q1 = b2.q1) on (b2.d2 = b1.q2) on (t1.f1 = b1.d1) left join int4_tbl i4 on (i8.q2 = i4.f1); QUERY PLAN ---------------------------------------------------------------------------- Hash Left Join Output: t1.f1 Hash Cond: (i8.q2 = i4.f1) -> Nested Loop Left Join Output: t1.f1, i8.q2 Join Filter: (t1.f1 = '***'::text) -> Seq Scan on public.text_tbl t1 Output: t1.f1 -> Materialize Output: i8.q2 -> Hash Right Join Output: i8.q2 Hash Cond: ((NULL::integer) = i8b1.q2) -> Hash Right Join Output: i8.q2, (NULL::integer) Hash Cond: (i8b2.q1 = i8.q1) -> Hash Join Output: i8b2.q1, NULL::integer Hash Cond: (i8b2.q1 = i4b2.f1) -> Seq Scan on public.int8_tbl i8b2 Output: i8b2.q1, i8b2.q2 -> Hash Output: i4b2.f1 -> Seq Scan on public.int4_tbl i4b2 Output: i4b2.f1 -> Hash Output: i8.q1, i8.q2 -> Seq Scan on public.int8_tbl i8 Output: i8.q1, i8.q2 -> Hash Output: i8b1.q2 -> Seq Scan on public.int8_tbl i8b1 Output: i8b1.q2 -> Hash Output: i4.f1 -> Seq Scan on public.int4_tbl i4 Output: i4.f1 (37 rows) select t1.* from text_tbl t1 left join (select *, '***'::text as d1 from int8_tbl i8b1) b1 left join int8_tbl i8 left join (select *, null::int as d2 from int8_tbl i8b2, int4_tbl i4b2 where q1 = f1) b2 on (i8.q1 = b2.q1) on (b2.d2 = b1.q2) on (t1.f1 = b1.d1) left join int4_tbl i4 on (i8.q2 = i4.f1); f1 ------------------- doh! hi de ho neighbor (2 rows) explain (verbose, costs off) select * from text_tbl t1 inner join int8_tbl i8 on i8.q2 = 456 right join text_tbl t2 on t1.f1 = 'doh!' left join int4_tbl i4 on i8.q1 = i4.f1; QUERY PLAN -------------------------------------------------------- Nested Loop Left Join Output: t1.f1, i8.q1, i8.q2, t2.f1, i4.f1 -> Seq Scan on public.text_tbl t2 Output: t2.f1 -> Materialize Output: i8.q1, i8.q2, i4.f1, t1.f1 -> Nested Loop Output: i8.q1, i8.q2, i4.f1, t1.f1 -> Nested Loop Left Join Output: i8.q1, i8.q2, i4.f1 Join Filter: (i8.q1 = i4.f1) -> Seq Scan on public.int8_tbl i8 Output: i8.q1, i8.q2 Filter: (i8.q2 = 456) -> Seq Scan on public.int4_tbl i4 Output: i4.f1 -> Seq Scan on public.text_tbl t1 Output: t1.f1 Filter: (t1.f1 = 'doh!'::text) (19 rows) select * from text_tbl t1 inner join int8_tbl i8 on i8.q2 = 456 right join text_tbl t2 on t1.f1 = 'doh!' left join int4_tbl i4 on i8.q1 = i4.f1; f1 | q1 | q2 | f1 | f1 ------+-----+-----+-------------------+---- doh! | 123 | 456 | doh! | doh! | 123 | 456 | hi de ho neighbor | (2 rows) -- check handling of a variable-free qual for a non-commutable outer join explain (costs off) select nspname from (select 1 as x) ss1 left join ( select n.nspname, c.relname from pg_class c left join pg_namespace n on n.oid = c.relnamespace where c.relkind = 'r' ) ss2 on false; QUERY PLAN -------------------------------- Nested Loop Left Join Join Filter: false -> Result -> Result One-Time Filter: false (5 rows) -- check handling of apparently-commutable outer joins with non-commutable -- joins between them explain (costs off) select 1 from int4_tbl i4 left join int8_tbl i8 on i4.f1 is not null left join (select 1 as a) ss1 on null join int4_tbl i42 on ss1.a is null or i8.q1 <> i8.q2 right join (select 2 as b) ss2 on ss2.b < i4.f1; QUERY PLAN ----------------------------------------------------------- Nested Loop Left Join -> Result -> Nested Loop -> Nested Loop Left Join Join Filter: NULL::boolean Filter: (((1) IS NULL) OR (i8.q1 <> i8.q2)) -> Nested Loop Left Join Join Filter: (i4.f1 IS NOT NULL) -> Seq Scan on int4_tbl i4 Filter: (2 < f1) -> Materialize -> Seq Scan on int8_tbl i8 -> Result One-Time Filter: false -> Materialize -> Seq Scan on int4_tbl i42 (16 rows) -- -- test for appropriate join order in the presence of lateral references -- explain (verbose, costs off) select * from text_tbl t1 left join int8_tbl i8 on i8.q2 = 123, lateral (select i8.q1, t2.f1 from text_tbl t2 limit 1) as ss where t1.f1 = ss.f1; QUERY PLAN -------------------------------------------------- Nested Loop Output: t1.f1, i8.q1, i8.q2, (i8.q1), t2.f1 Join Filter: (t1.f1 = t2.f1) -> Nested Loop Left Join Output: t1.f1, i8.q1, i8.q2 -> Seq Scan on public.text_tbl t1 Output: t1.f1 -> Materialize Output: i8.q1, i8.q2 -> Seq Scan on public.int8_tbl i8 Output: i8.q1, i8.q2 Filter: (i8.q2 = 123) -> Memoize Output: (i8.q1), t2.f1 Cache Key: i8.q1 Cache Mode: binary -> Limit Output: (i8.q1), t2.f1 -> Seq Scan on public.text_tbl t2 Output: i8.q1, t2.f1 (20 rows) select * from text_tbl t1 left join int8_tbl i8 on i8.q2 = 123, lateral (select i8.q1, t2.f1 from text_tbl t2 limit 1) as ss where t1.f1 = ss.f1; f1 | q1 | q2 | q1 | f1 ------+------------------+-----+------------------+------ doh! | 4567890123456789 | 123 | 4567890123456789 | doh! (1 row) explain (verbose, costs off) select * from text_tbl t1 left join int8_tbl i8 on i8.q2 = 123, lateral (select i8.q1, t2.f1 from text_tbl t2 limit 1) as ss1, lateral (select ss1.* from text_tbl t3 limit 1) as ss2 where t1.f1 = ss2.f1; QUERY PLAN ------------------------------------------------------------------- Nested Loop Output: t1.f1, i8.q1, i8.q2, (i8.q1), t2.f1, ((i8.q1)), (t2.f1) Join Filter: (t1.f1 = (t2.f1)) -> Nested Loop Output: t1.f1, i8.q1, i8.q2, (i8.q1), t2.f1 -> Nested Loop Left Join Output: t1.f1, i8.q1, i8.q2 -> Seq Scan on public.text_tbl t1 Output: t1.f1 -> Materialize Output: i8.q1, i8.q2 -> Seq Scan on public.int8_tbl i8 Output: i8.q1, i8.q2 Filter: (i8.q2 = 123) -> Memoize Output: (i8.q1), t2.f1 Cache Key: i8.q1 Cache Mode: binary -> Limit Output: (i8.q1), t2.f1 -> Seq Scan on public.text_tbl t2 Output: i8.q1, t2.f1 -> Memoize Output: ((i8.q1)), (t2.f1) Cache Key: (i8.q1), t2.f1 Cache Mode: binary -> Limit Output: ((i8.q1)), (t2.f1) -> Seq Scan on public.text_tbl t3 Output: (i8.q1), t2.f1 (30 rows) select * from text_tbl t1 left join int8_tbl i8 on i8.q2 = 123, lateral (select i8.q1, t2.f1 from text_tbl t2 limit 1) as ss1, lateral (select ss1.* from text_tbl t3 limit 1) as ss2 where t1.f1 = ss2.f1; f1 | q1 | q2 | q1 | f1 | q1 | f1 ------+------------------+-----+------------------+------+------------------+------ doh! | 4567890123456789 | 123 | 4567890123456789 | doh! | 4567890123456789 | doh! (1 row) explain (verbose, costs off) select 1 from text_tbl as tt1 inner join text_tbl as tt2 on (tt1.f1 = 'foo') left join text_tbl as tt3 on (tt3.f1 = 'foo') left join text_tbl as tt4 on (tt3.f1 = tt4.f1), lateral (select tt4.f1 as c0 from text_tbl as tt5 limit 1) as ss1 where tt1.f1 = ss1.c0; QUERY PLAN ---------------------------------------------------------- Nested Loop Output: 1 -> Nested Loop Left Join Output: tt1.f1, tt4.f1 -> Nested Loop Output: tt1.f1 -> Seq Scan on public.text_tbl tt1 Output: tt1.f1 Filter: (tt1.f1 = 'foo'::text) -> Seq Scan on public.text_tbl tt2 Output: tt2.f1 -> Materialize Output: tt4.f1 -> Nested Loop Left Join Output: tt4.f1 -> Seq Scan on public.text_tbl tt3 Output: tt3.f1 Filter: (tt3.f1 = 'foo'::text) -> Seq Scan on public.text_tbl tt4 Output: tt4.f1 Filter: (tt4.f1 = 'foo'::text) -> Memoize Output: ss1.c0 Cache Key: tt4.f1 Cache Mode: binary -> Subquery Scan on ss1 Output: ss1.c0 Filter: (ss1.c0 = 'foo'::text) -> Limit Output: (tt4.f1) -> Seq Scan on public.text_tbl tt5 Output: tt4.f1 (32 rows) select 1 from text_tbl as tt1 inner join text_tbl as tt2 on (tt1.f1 = 'foo') left join text_tbl as tt3 on (tt3.f1 = 'foo') left join text_tbl as tt4 on (tt3.f1 = tt4.f1), lateral (select tt4.f1 as c0 from text_tbl as tt5 limit 1) as ss1 where tt1.f1 = ss1.c0; ?column? ---------- (0 rows) explain (verbose, costs off) select 1 from int4_tbl as i4 inner join ((select 42 as n from int4_tbl x1 left join int8_tbl x2 on f1 = q1) as ss1 right join (select 1 as z) as ss2 on true) on false, lateral (select i4.f1, ss1.n from int8_tbl as i8 limit 1) as ss3; QUERY PLAN -------------------------- Result Output: 1 One-Time Filter: false (3 rows) select 1 from int4_tbl as i4 inner join ((select 42 as n from int4_tbl x1 left join int8_tbl x2 on f1 = q1) as ss1 right join (select 1 as z) as ss2 on true) on false, lateral (select i4.f1, ss1.n from int8_tbl as i8 limit 1) as ss3; ?column? ---------- (0 rows) -- -- check a case in which a PlaceHolderVar forces join order -- explain (verbose, costs off) select ss2.* from int4_tbl i41 left join int8_tbl i8 join (select i42.f1 as c1, i43.f1 as c2, 42 as c3 from int4_tbl i42, int4_tbl i43) ss1 on i8.q1 = ss1.c2 on i41.f1 = ss1.c1, lateral (select i41.*, i8.*, ss1.* from text_tbl limit 1) ss2 where ss1.c2 = 0; QUERY PLAN ------------------------------------------------------------------------ Nested Loop Output: (i41.f1), (i8.q1), (i8.q2), (i42.f1), (i43.f1), ((42)) -> Hash Join Output: i41.f1, i42.f1, i8.q1, i8.q2, i43.f1, 42 Hash Cond: (i41.f1 = i42.f1) -> Nested Loop Output: i8.q1, i8.q2, i43.f1, i41.f1 -> Nested Loop Output: i8.q1, i8.q2, i43.f1 -> Seq Scan on public.int8_tbl i8 Output: i8.q1, i8.q2 Filter: (i8.q1 = 0) -> Seq Scan on public.int4_tbl i43 Output: i43.f1 Filter: (i43.f1 = 0) -> Seq Scan on public.int4_tbl i41 Output: i41.f1 -> Hash Output: i42.f1 -> Seq Scan on public.int4_tbl i42 Output: i42.f1 -> Limit Output: (i41.f1), (i8.q1), (i8.q2), (i42.f1), (i43.f1), ((42)) -> Seq Scan on public.text_tbl Output: i41.f1, i8.q1, i8.q2, i42.f1, i43.f1, (42) (25 rows) select ss2.* from int4_tbl i41 left join int8_tbl i8 join (select i42.f1 as c1, i43.f1 as c2, 42 as c3 from int4_tbl i42, int4_tbl i43) ss1 on i8.q1 = ss1.c2 on i41.f1 = ss1.c1, lateral (select i41.*, i8.*, ss1.* from text_tbl limit 1) ss2 where ss1.c2 = 0; f1 | q1 | q2 | c1 | c2 | c3 ----+----+----+----+----+---- (0 rows) -- -- test successful handling of full join underneath left join (bug #14105) -- explain (costs off) select * from (select 1 as id) as xx left join (tenk1 as a1 full join (select 1 as id) as yy on (a1.unique1 = yy.id)) on (xx.id = coalesce(yy.id)); QUERY PLAN --------------------------------------- Nested Loop Left Join -> Result -> Hash Full Join Hash Cond: (a1.unique1 = (1)) Filter: (1 = COALESCE((1))) -> Seq Scan on tenk1 a1 -> Hash -> Result (8 rows) select * from (select 1 as id) as xx left join (tenk1 as a1 full join (select 1 as id) as yy on (a1.unique1 = yy.id)) on (xx.id = coalesce(yy.id)); id | unique1 | unique2 | two | four | ten | twenty | hundred | thousand | twothousand | fivethous | tenthous | odd | even | stringu1 | stringu2 | string4 | id ----+---------+---------+-----+------+-----+--------+---------+----------+-------------+-----------+----------+-----+------+----------+----------+---------+---- 1 | 1 | 2838 | 1 | 1 | 1 | 1 | 1 | 1 | 1 | 1 | 1 | 2 | 3 | BAAAAA | EFEAAA | OOOOxx | 1 (1 row) -- -- test ability to push constants through outer join clauses -- explain (costs off) select * from int4_tbl a left join tenk1 b on f1 = unique2 where f1 = 0; QUERY PLAN ------------------------------------------------- Nested Loop Left Join -> Seq Scan on int4_tbl a Filter: (f1 = 0) -> Index Scan using tenk1_unique2 on tenk1 b Index Cond: (unique2 = 0) (5 rows) explain (costs off) select * from tenk1 a full join tenk1 b using(unique2) where unique2 = 42; QUERY PLAN ------------------------------------------------- Merge Full Join -> Index Scan using tenk1_unique2 on tenk1 a Index Cond: (unique2 = 42) -> Index Scan using tenk1_unique2 on tenk1 b Index Cond: (unique2 = 42) (5 rows) -- -- test that quals attached to an outer join have correct semantics, -- specifically that they don't re-use expressions computed below the join; -- we force a mergejoin so that coalesce(b.q1, 1) appears as a join input -- set enable_hashjoin to off; set enable_nestloop to off; explain (verbose, costs off) select a.q2, b.q1 from int8_tbl a left join int8_tbl b on a.q2 = coalesce(b.q1, 1) where coalesce(b.q1, 1) > 0; QUERY PLAN --------------------------------------------------------- Merge Left Join Output: a.q2, b.q1 Merge Cond: (a.q2 = (COALESCE(b.q1, '1'::bigint))) Filter: (COALESCE(b.q1, '1'::bigint) > 0) -> Sort Output: a.q2 Sort Key: a.q2 -> Seq Scan on public.int8_tbl a Output: a.q2 -> Sort Output: b.q1, (COALESCE(b.q1, '1'::bigint)) Sort Key: (COALESCE(b.q1, '1'::bigint)) -> Seq Scan on public.int8_tbl b Output: b.q1, COALESCE(b.q1, '1'::bigint) (14 rows) select a.q2, b.q1 from int8_tbl a left join int8_tbl b on a.q2 = coalesce(b.q1, 1) where coalesce(b.q1, 1) > 0; q2 | q1 -------------------+------------------ -4567890123456789 | 123 | 123 123 | 123 456 | 4567890123456789 | 4567890123456789 4567890123456789 | 4567890123456789 4567890123456789 | 4567890123456789 4567890123456789 | 4567890123456789 4567890123456789 | 4567890123456789 4567890123456789 | 4567890123456789 (10 rows) reset enable_hashjoin; reset enable_nestloop; -- -- test join strength reduction with a SubPlan providing the proof -- explain (costs off) select a.unique1, b.unique2 from onek a left join onek b on a.unique1 = b.unique2 where b.unique2 = any (select q1 from int8_tbl c where c.q1 < b.unique1); QUERY PLAN ---------------------------------------------------------- Hash Join Hash Cond: (b.unique2 = a.unique1) -> Seq Scan on onek b Filter: (SubPlan 1) SubPlan 1 -> Seq Scan on int8_tbl c Filter: (q1 < b.unique1) -> Hash -> Index Only Scan using onek_unique1 on onek a (9 rows) select a.unique1, b.unique2 from onek a left join onek b on a.unique1 = b.unique2 where b.unique2 = any (select q1 from int8_tbl c where c.q1 < b.unique1); unique1 | unique2 ---------+--------- 123 | 123 (1 row) -- -- test full-join strength reduction -- explain (costs off) select a.unique1, b.unique2 from onek a full join onek b on a.unique1 = b.unique2 where a.unique1 = 42; QUERY PLAN ---------------------------------------------------- Nested Loop Left Join -> Index Only Scan using onek_unique1 on onek a Index Cond: (unique1 = 42) -> Index Only Scan using onek_unique2 on onek b Index Cond: (unique2 = 42) (5 rows) select a.unique1, b.unique2 from onek a full join onek b on a.unique1 = b.unique2 where a.unique1 = 42; unique1 | unique2 ---------+--------- 42 | 42 (1 row) explain (costs off) select a.unique1, b.unique2 from onek a full join onek b on a.unique1 = b.unique2 where b.unique2 = 43; QUERY PLAN ---------------------------------------------------- Nested Loop Left Join -> Index Only Scan using onek_unique2 on onek b Index Cond: (unique2 = 43) -> Index Only Scan using onek_unique1 on onek a Index Cond: (unique1 = 43) (5 rows) select a.unique1, b.unique2 from onek a full join onek b on a.unique1 = b.unique2 where b.unique2 = 43; unique1 | unique2 ---------+--------- 43 | 43 (1 row) explain (costs off) select a.unique1, b.unique2 from onek a full join onek b on a.unique1 = b.unique2 where a.unique1 = 42 and b.unique2 = 42; QUERY PLAN ---------------------------------------------------- Nested Loop -> Index Only Scan using onek_unique1 on onek a Index Cond: (unique1 = 42) -> Index Only Scan using onek_unique2 on onek b Index Cond: (unique2 = 42) (5 rows) select a.unique1, b.unique2 from onek a full join onek b on a.unique1 = b.unique2 where a.unique1 = 42 and b.unique2 = 42; unique1 | unique2 ---------+--------- 42 | 42 (1 row) -- -- test result-RTE removal underneath a full join -- explain (costs off) select * from (select * from int8_tbl i81 join (values(123,2)) v(v1,v2) on q2=v1) ss1 full join (select * from (values(456,2)) w(v1,v2) join int8_tbl i82 on q2=v1) ss2 on true; QUERY PLAN -------------------------------------- Merge Full Join -> Seq Scan on int8_tbl i81 Filter: (q2 = 123) -> Materialize -> Seq Scan on int8_tbl i82 Filter: (q2 = 456) (6 rows) select * from (select * from int8_tbl i81 join (values(123,2)) v(v1,v2) on q2=v1) ss1 full join (select * from (values(456,2)) w(v1,v2) join int8_tbl i82 on q2=v1) ss2 on true; q1 | q2 | v1 | v2 | v1 | v2 | q1 | q2 ------------------+-----+-----+----+-----+----+-----+----- 4567890123456789 | 123 | 123 | 2 | 456 | 2 | 123 | 456 (1 row) -- -- test join removal -- begin; CREATE TEMP TABLE a (id int PRIMARY KEY, b_id int); CREATE TEMP TABLE b (id int PRIMARY KEY, c_id int); CREATE TEMP TABLE c (id int PRIMARY KEY); CREATE TEMP TABLE d (a int, b int); INSERT INTO a VALUES (0, 0), (1, NULL); INSERT INTO b VALUES (0, 0), (1, NULL); INSERT INTO c VALUES (0), (1); INSERT INTO d VALUES (1,3), (2,2), (3,1); -- all three cases should be optimizable into a simple seqscan explain (costs off) SELECT a.* FROM a LEFT JOIN b ON a.b_id = b.id; QUERY PLAN --------------- Seq Scan on a (1 row) explain (costs off) SELECT b.* FROM b LEFT JOIN c ON b.c_id = c.id; QUERY PLAN --------------- Seq Scan on b (1 row) explain (costs off) SELECT a.* FROM a LEFT JOIN (b left join c on b.c_id = c.id) ON (a.b_id = b.id); QUERY PLAN --------------- Seq Scan on a (1 row) -- check optimization of outer join within another special join explain (costs off) select id from a where id in ( select b.id from b left join c on b.id = c.id ); QUERY PLAN ---------------------------- Hash Join Hash Cond: (a.id = b.id) -> Seq Scan on a -> Hash -> Seq Scan on b (5 rows) -- check optimization with oddly-nested outer joins explain (costs off) select a1.id from (a a1 left join a a2 on true) left join (a a3 left join a a4 on a3.id = a4.id) on a2.id = a3.id; QUERY PLAN ------------------------------ Nested Loop Left Join -> Seq Scan on a a1 -> Materialize -> Seq Scan on a a2 (4 rows) explain (costs off) select a1.id from (a a1 left join a a2 on a1.id = a2.id) left join (a a3 left join a a4 on a3.id = a4.id) on a2.id = a3.id; QUERY PLAN ------------------ Seq Scan on a a1 (1 row) -- another example (bug #17781) explain (costs off) select ss1.f1 from int4_tbl as t1 left join (int4_tbl as t2 right join int4_tbl as t3 on null left join (int4_tbl as t4 right join int8_tbl as t5 on null) on t2.f1 = t4.f1 left join ((select null as f1 from int4_tbl as t6) as ss1 inner join int8_tbl as t7 on null) on t5.q1 = t7.q2) on false; QUERY PLAN -------------------------------- Nested Loop Left Join Join Filter: false -> Seq Scan on int4_tbl t1 -> Result One-Time Filter: false (5 rows) -- variant with Var rather than PHV coming from t6 explain (costs off) select ss1.f1 from int4_tbl as t1 left join (int4_tbl as t2 right join int4_tbl as t3 on null left join (int4_tbl as t4 right join int8_tbl as t5 on null) on t2.f1 = t4.f1 left join ((select f1 from int4_tbl as t6) as ss1 inner join int8_tbl as t7 on null) on t5.q1 = t7.q2) on false; QUERY PLAN -------------------------------- Nested Loop Left Join Join Filter: false -> Seq Scan on int4_tbl t1 -> Result One-Time Filter: false (5 rows) -- per further discussion of bug #17781 explain (costs off) select ss1.x from (select f1/2 as x from int4_tbl i4 left join a on a.id = i4.f1) ss1 right join int8_tbl i8 on true where current_user is not null; -- this is to add a Result node QUERY PLAN ----------------------------------------------- Result One-Time Filter: (CURRENT_USER IS NOT NULL) -> Nested Loop Left Join -> Seq Scan on int8_tbl i8 -> Materialize -> Seq Scan on int4_tbl i4 (6 rows) -- and further discussion of bug #17781 explain (costs off) select * from int8_tbl t1 left join (int8_tbl t2 left join onek t3 on t2.q1 > t3.unique1) on t1.q2 = t2.q2 left join onek t4 on t2.q2 < t3.unique2; QUERY PLAN ------------------------------------------------- Nested Loop Left Join Join Filter: (t2.q2 < t3.unique2) -> Nested Loop Left Join Join Filter: (t2.q1 > t3.unique1) -> Hash Left Join Hash Cond: (t1.q2 = t2.q2) -> Seq Scan on int8_tbl t1 -> Hash -> Seq Scan on int8_tbl t2 -> Materialize -> Seq Scan on onek t3 -> Materialize -> Seq Scan on onek t4 (13 rows) -- More tests of correct placement of pseudoconstant quals -- simple constant-false condition explain (costs off) select * from int8_tbl t1 left join (int8_tbl t2 inner join int8_tbl t3 on false left join int8_tbl t4 on t2.q2 = t4.q2) on t1.q1 = t2.q1; QUERY PLAN -------------------------------------- Hash Left Join Hash Cond: (t1.q1 = q1) -> Seq Scan on int8_tbl t1 -> Hash -> Result One-Time Filter: false (6 rows) -- deduce constant-false from an EquivalenceClass explain (costs off) select * from int8_tbl t1 left join (int8_tbl t2 inner join int8_tbl t3 on (t2.q1-t3.q2) = 0 and (t2.q1-t3.q2) = 1 left join int8_tbl t4 on t2.q2 = t4.q2) on t1.q1 = t2.q1; QUERY PLAN -------------------------------------- Hash Left Join Hash Cond: (t1.q1 = q1) -> Seq Scan on int8_tbl t1 -> Hash -> Result One-Time Filter: false (6 rows) -- pseudoconstant based on an outer-level Param explain (costs off) select exists( select * from int8_tbl t1 left join (int8_tbl t2 inner join int8_tbl t3 on x0.f1 = 1 left join int8_tbl t4 on t2.q2 = t4.q2) on t1.q1 = t2.q1 ) from int4_tbl x0; QUERY PLAN --------------------------------------------------------------------- Seq Scan on int4_tbl x0 SubPlan 1 -> Nested Loop Left Join Join Filter: (t2.q2 = t4.q2) -> Nested Loop Left Join Join Filter: (t1.q1 = t2.q1) -> Seq Scan on int8_tbl t1 -> Materialize -> Result One-Time Filter: (x0.f1 = 1) -> Nested Loop -> Seq Scan on int8_tbl t2 -> Materialize -> Seq Scan on int8_tbl t3 -> Materialize -> Seq Scan on int8_tbl t4 (16 rows) -- check that join removal works for a left join when joining a subquery -- that is guaranteed to be unique by its GROUP BY clause explain (costs off) select d.* from d left join (select * from b group by b.id, b.c_id) s on d.a = s.id and d.b = s.c_id; QUERY PLAN --------------- Seq Scan on d (1 row) -- similarly, but keying off a DISTINCT clause explain (costs off) select d.* from d left join (select distinct * from b) s on d.a = s.id and d.b = s.c_id; QUERY PLAN --------------- Seq Scan on d (1 row) -- join removal is not possible when the GROUP BY contains a column that is -- not in the join condition. (Note: as of 9.6, we notice that b.id is a -- primary key and so drop b.c_id from the GROUP BY of the resulting plan; -- but this happens too late for join removal in the outer plan level.) explain (costs off) select d.* from d left join (select * from b group by b.id, b.c_id) s on d.a = s.id; QUERY PLAN ------------------------------------------ Merge Right Join Merge Cond: (b.id = d.a) -> Group Group Key: b.id -> Index Scan using b_pkey on b -> Sort Sort Key: d.a -> Seq Scan on d (8 rows) -- similarly, but keying off a DISTINCT clause explain (costs off) select d.* from d left join (select distinct * from b) s on d.a = s.id; QUERY PLAN -------------------------------------- Merge Right Join Merge Cond: (b.id = d.a) -> Unique -> Sort Sort Key: b.id, b.c_id -> Seq Scan on b -> Sort Sort Key: d.a -> Seq Scan on d (9 rows) -- join removal is not possible here explain (costs off) select 1 from a t1 left join (a t2 left join a t3 on t2.id = 1) on t2.id = 1; QUERY PLAN -------------------------------------------------------- Nested Loop Left Join -> Seq Scan on a t1 -> Materialize -> Nested Loop Left Join Join Filter: (t2.id = 1) -> Index Only Scan using a_pkey on a t2 Index Cond: (id = 1) -> Seq Scan on a t3 (8 rows) -- check join removal works when uniqueness of the join condition is enforced -- by a UNION explain (costs off) select d.* from d left join (select id from a union select id from b) s on d.a = s.id; QUERY PLAN --------------- Seq Scan on d (1 row) -- check join removal with a cross-type comparison operator explain (costs off) select i8.* from int8_tbl i8 left join (select f1 from int4_tbl group by f1) i4 on i8.q1 = i4.f1; QUERY PLAN ------------------------- Seq Scan on int8_tbl i8 (1 row) -- check join removal with lateral references explain (costs off) select 1 from (select a.id FROM a left join b on a.b_id = b.id) q, lateral generate_series(1, q.id) gs(i) where q.id = gs.i; QUERY PLAN ------------------------------------------- Nested Loop -> Seq Scan on a -> Function Scan on generate_series gs Filter: (a.id = i) (4 rows) -- check join removal within RHS of an outer join explain (costs off) select c.id, ss.a from c left join (select d.a from onerow, d left join b on d.a = b.id) ss on c.id = ss.a; QUERY PLAN -------------------------------- Hash Right Join Hash Cond: (d.a = c.id) -> Nested Loop -> Seq Scan on onerow -> Seq Scan on d -> Hash -> Seq Scan on c (7 rows) CREATE TEMP TABLE parted_b (id int PRIMARY KEY) partition by range(id); CREATE TEMP TABLE parted_b1 partition of parted_b for values from (0) to (10); -- test join removals on a partitioned table explain (costs off) select a.* from a left join parted_b pb on a.b_id = pb.id; QUERY PLAN --------------- Seq Scan on a (1 row) rollback; create temp table parent (k int primary key, pd int); create temp table child (k int unique, cd int); insert into parent values (1, 10), (2, 20), (3, 30); insert into child values (1, 100), (4, 400); -- this case is optimizable select p.* from parent p left join child c on (p.k = c.k); k | pd ---+---- 1 | 10 2 | 20 3 | 30 (3 rows) explain (costs off) select p.* from parent p left join child c on (p.k = c.k); QUERY PLAN ---------------------- Seq Scan on parent p (1 row) -- this case is not select p.*, linked from parent p left join (select c.*, true as linked from child c) as ss on (p.k = ss.k); k | pd | linked ---+----+-------- 1 | 10 | t 2 | 20 | 3 | 30 | (3 rows) explain (costs off) select p.*, linked from parent p left join (select c.*, true as linked from child c) as ss on (p.k = ss.k); QUERY PLAN --------------------------------- Hash Left Join Hash Cond: (p.k = c.k) -> Seq Scan on parent p -> Hash -> Seq Scan on child c (5 rows) -- check for a 9.0rc1 bug: join removal breaks pseudoconstant qual handling select p.* from parent p left join child c on (p.k = c.k) where p.k = 1 and p.k = 2; k | pd ---+---- (0 rows) explain (costs off) select p.* from parent p left join child c on (p.k = c.k) where p.k = 1 and p.k = 2; QUERY PLAN ------------------------------------------------ Result One-Time Filter: false -> Index Scan using parent_pkey on parent p Index Cond: (k = 1) (4 rows) select p.* from (parent p left join child c on (p.k = c.k)) join parent x on p.k = x.k where p.k = 1 and p.k = 2; k | pd ---+---- (0 rows) explain (costs off) select p.* from (parent p left join child c on (p.k = c.k)) join parent x on p.k = x.k where p.k = 1 and p.k = 2; QUERY PLAN -------------------------- Result One-Time Filter: false (2 rows) -- bug 5255: this is not optimizable by join removal begin; CREATE TEMP TABLE a (id int PRIMARY KEY); CREATE TEMP TABLE b (id int PRIMARY KEY, a_id int); INSERT INTO a VALUES (0), (1); INSERT INTO b VALUES (0, 0), (1, NULL); SELECT * FROM b LEFT JOIN a ON (b.a_id = a.id) WHERE (a.id IS NULL OR a.id > 0); id | a_id | id ----+------+---- 1 | | (1 row) SELECT b.* FROM b LEFT JOIN a ON (b.a_id = a.id) WHERE (a.id IS NULL OR a.id > 0); id | a_id ----+------ 1 | (1 row) rollback; -- another join removal bug: this is not optimizable, either begin; create temp table innertab (id int8 primary key, dat1 int8); insert into innertab values(123, 42); SELECT * FROM (SELECT 1 AS x) ss1 LEFT JOIN (SELECT q1, q2, COALESCE(dat1, q1) AS y FROM int8_tbl LEFT JOIN innertab ON q2 = id) ss2 ON true; x | q1 | q2 | y ---+------------------+-------------------+------------------ 1 | 123 | 456 | 123 1 | 123 | 4567890123456789 | 123 1 | 4567890123456789 | 123 | 42 1 | 4567890123456789 | 4567890123456789 | 4567890123456789 1 | 4567890123456789 | -4567890123456789 | 4567890123456789 (5 rows) -- join removal bug #17769: can't remove if there's a pushed-down reference EXPLAIN (COSTS OFF) SELECT q2 FROM (SELECT * FROM int8_tbl LEFT JOIN innertab ON q2 = id) ss WHERE COALESCE(dat1, 0) = q1; QUERY PLAN ---------------------------------------------------------------- Nested Loop Left Join Filter: (COALESCE(innertab.dat1, '0'::bigint) = int8_tbl.q1) -> Seq Scan on int8_tbl -> Index Scan using innertab_pkey on innertab Index Cond: (id = int8_tbl.q2) (5 rows) -- join removal bug #17773: otherwise-removable PHV appears in a qual condition EXPLAIN (VERBOSE, COSTS OFF) SELECT q2 FROM (SELECT q2, 'constant'::text AS x FROM int8_tbl LEFT JOIN innertab ON q2 = id) ss RIGHT JOIN int4_tbl ON NULL WHERE x >= x; QUERY PLAN ------------------------------------------------------ Nested Loop Left Join Output: q2 Join Filter: NULL::boolean Filter: (('constant'::text) >= ('constant'::text)) -> Seq Scan on public.int4_tbl Output: int4_tbl.f1 -> Result Output: q2, 'constant'::text One-Time Filter: false (9 rows) -- join removal bug #17786: check that OR conditions are cleaned up EXPLAIN (COSTS OFF) SELECT f1, x FROM int4_tbl JOIN ((SELECT 42 AS x FROM int8_tbl LEFT JOIN innertab ON q1 = id) AS ss1 RIGHT JOIN tenk1 ON NULL) ON tenk1.unique1 = ss1.x OR tenk1.unique2 = ss1.x; QUERY PLAN -------------------------------------------------------------------------- Nested Loop -> Seq Scan on int4_tbl -> Materialize -> Nested Loop Left Join Join Filter: NULL::boolean Filter: ((tenk1.unique1 = (42)) OR (tenk1.unique2 = (42))) -> Seq Scan on tenk1 -> Result One-Time Filter: false (9 rows) rollback; -- another join removal bug: we must clean up correctly when removing a PHV begin; create temp table uniquetbl (f1 text unique); explain (costs off) select t1.* from uniquetbl as t1 left join (select *, '***'::text as d1 from uniquetbl) t2 on t1.f1 = t2.f1 left join uniquetbl t3 on t2.d1 = t3.f1; QUERY PLAN -------------------------- Seq Scan on uniquetbl t1 (1 row) explain (costs off) select t0.* from text_tbl t0 left join (select case t1.ten when 0 then 'doh!'::text else null::text end as case1, t1.stringu2 from tenk1 t1 join int4_tbl i4 ON i4.f1 = t1.unique2 left join uniquetbl u1 ON u1.f1 = t1.string4) ss on t0.f1 = ss.case1 where ss.stringu2 !~* ss.case1; QUERY PLAN -------------------------------------------------------------------------------------------- Nested Loop Join Filter: (t0.f1 = CASE t1.ten WHEN 0 THEN 'doh!'::text ELSE NULL::text END) -> Nested Loop -> Seq Scan on int4_tbl i4 -> Index Scan using tenk1_unique2 on tenk1 t1 Index Cond: (unique2 = i4.f1) Filter: (stringu2 !~* CASE ten WHEN 0 THEN 'doh!'::text ELSE NULL::text END) -> Materialize -> Seq Scan on text_tbl t0 (9 rows) select t0.* from text_tbl t0 left join (select case t1.ten when 0 then 'doh!'::text else null::text end as case1, t1.stringu2 from tenk1 t1 join int4_tbl i4 ON i4.f1 = t1.unique2 left join uniquetbl u1 ON u1.f1 = t1.string4) ss on t0.f1 = ss.case1 where ss.stringu2 !~* ss.case1; f1 ------ doh! (1 row) rollback; -- test case to expose miscomputation of required relid set for a PHV explain (verbose, costs off) select i8.*, ss.v, t.unique2 from int8_tbl i8 left join int4_tbl i4 on i4.f1 = 1 left join lateral (select i4.f1 + 1 as v) as ss on true left join tenk1 t on t.unique2 = ss.v where q2 = 456; QUERY PLAN ------------------------------------------------------------- Nested Loop Left Join Output: i8.q1, i8.q2, ((i4.f1 + 1)), t.unique2 -> Nested Loop Left Join Output: i8.q1, i8.q2, (i4.f1 + 1) -> Seq Scan on public.int8_tbl i8 Output: i8.q1, i8.q2 Filter: (i8.q2 = 456) -> Seq Scan on public.int4_tbl i4 Output: i4.f1 Filter: (i4.f1 = 1) -> Index Only Scan using tenk1_unique2 on public.tenk1 t Output: t.unique2 Index Cond: (t.unique2 = ((i4.f1 + 1))) (13 rows) select i8.*, ss.v, t.unique2 from int8_tbl i8 left join int4_tbl i4 on i4.f1 = 1 left join lateral (select i4.f1 + 1 as v) as ss on true left join tenk1 t on t.unique2 = ss.v where q2 = 456; q1 | q2 | v | unique2 -----+-----+---+--------- 123 | 456 | | (1 row) -- and check a related issue where we miscompute required relids for -- a PHV that's been translated to a child rel create temp table parttbl (a integer primary key) partition by range (a); create temp table parttbl1 partition of parttbl for values from (1) to (100); insert into parttbl values (11), (12); explain (costs off) select * from (select *, 12 as phv from parttbl) as ss right join int4_tbl on true where ss.a = ss.phv and f1 = 0; QUERY PLAN ------------------------------------ Nested Loop -> Seq Scan on int4_tbl Filter: (f1 = 0) -> Seq Scan on parttbl1 parttbl Filter: (a = 12) (5 rows) select * from (select *, 12 as phv from parttbl) as ss right join int4_tbl on true where ss.a = ss.phv and f1 = 0; a | phv | f1 ----+-----+---- 12 | 12 | 0 (1 row) -- bug #8444: we've historically allowed duplicate aliases within aliased JOINs select * from int8_tbl x join (int4_tbl x cross join int4_tbl y) j on q1 = f1; -- error ERROR: column reference "f1" is ambiguous LINE 2: ..._tbl x join (int4_tbl x cross join int4_tbl y) j on q1 = f1; ^ select * from int8_tbl x join (int4_tbl x cross join int4_tbl y) j on q1 = y.f1; -- error ERROR: invalid reference to FROM-clause entry for table "y" LINE 2: ...bl x join (int4_tbl x cross join int4_tbl y) j on q1 = y.f1; ^ DETAIL: There is an entry for table "y", but it cannot be referenced from this part of the query. select * from int8_tbl x join (int4_tbl x cross join int4_tbl y(ff)) j on q1 = f1; -- ok q1 | q2 | f1 | ff ----+----+----+---- (0 rows) -- -- Test hints given on incorrect column references are useful -- select t1.uunique1 from tenk1 t1 join tenk2 t2 on t1.two = t2.two; -- error, prefer "t1" suggestion ERROR: column t1.uunique1 does not exist LINE 1: select t1.uunique1 from ^ HINT: Perhaps you meant to reference the column "t1.unique1". select t2.uunique1 from tenk1 t1 join tenk2 t2 on t1.two = t2.two; -- error, prefer "t2" suggestion ERROR: column t2.uunique1 does not exist LINE 1: select t2.uunique1 from ^ HINT: Perhaps you meant to reference the column "t2.unique1". select uunique1 from tenk1 t1 join tenk2 t2 on t1.two = t2.two; -- error, suggest both at once ERROR: column "uunique1" does not exist LINE 1: select uunique1 from ^ HINT: Perhaps you meant to reference the column "t1.unique1" or the column "t2.unique1". select ctid from tenk1 t1 join tenk2 t2 on t1.two = t2.two; -- error, need qualification ERROR: column "ctid" does not exist LINE 1: select ctid from ^ DETAIL: There are columns named "ctid", but they are in tables that cannot be referenced from this part of the query. HINT: Try using a table-qualified name. -- -- Take care to reference the correct RTE -- select atts.relid::regclass, s.* from pg_stats s join pg_attribute a on s.attname = a.attname and s.tablename = a.attrelid::regclass::text join (select unnest(indkey) attnum, indexrelid from pg_index i) atts on atts.attnum = a.attnum where schemaname != 'pg_catalog'; ERROR: column atts.relid does not exist LINE 1: select atts.relid::regclass, s.* from pg_stats s join ^ -- Test bug in rangetable flattening explain (verbose, costs off) select 1 from (select * from int8_tbl where q1 <> (select 42) offset 0) ss where false; QUERY PLAN -------------------------- Result Output: 1 One-Time Filter: false (3 rows) -- -- Test LATERAL -- select unique2, x.* from tenk1 a, lateral (select * from int4_tbl b where f1 = a.unique1) x; unique2 | f1 ---------+---- 9998 | 0 (1 row) explain (costs off) select unique2, x.* from tenk1 a, lateral (select * from int4_tbl b where f1 = a.unique1) x; QUERY PLAN ------------------------------------------------- Nested Loop -> Seq Scan on int4_tbl b -> Index Scan using tenk1_unique1 on tenk1 a Index Cond: (unique1 = b.f1) (4 rows) select unique2, x.* from int4_tbl x, lateral (select unique2 from tenk1 where f1 = unique1) ss; unique2 | f1 ---------+---- 9998 | 0 (1 row) explain (costs off) select unique2, x.* from int4_tbl x, lateral (select unique2 from tenk1 where f1 = unique1) ss; QUERY PLAN ----------------------------------------------- Nested Loop -> Seq Scan on int4_tbl x -> Index Scan using tenk1_unique1 on tenk1 Index Cond: (unique1 = x.f1) (4 rows) explain (costs off) select unique2, x.* from int4_tbl x cross join lateral (select unique2 from tenk1 where f1 = unique1) ss; QUERY PLAN ----------------------------------------------- Nested Loop -> Seq Scan on int4_tbl x -> Index Scan using tenk1_unique1 on tenk1 Index Cond: (unique1 = x.f1) (4 rows) select unique2, x.* from int4_tbl x left join lateral (select unique1, unique2 from tenk1 where f1 = unique1) ss on true; unique2 | f1 ---------+------------- 9998 | 0 | 123456 | -123456 | 2147483647 | -2147483647 (5 rows) explain (costs off) select unique2, x.* from int4_tbl x left join lateral (select unique1, unique2 from tenk1 where f1 = unique1) ss on true; QUERY PLAN ----------------------------------------------- Nested Loop Left Join -> Seq Scan on int4_tbl x -> Index Scan using tenk1_unique1 on tenk1 Index Cond: (unique1 = x.f1) (4 rows) -- check scoping of lateral versus parent references -- the first of these should return int8_tbl.q2, the second int8_tbl.q1 select *, (select r from (select q1 as q2) x, (select q2 as r) y) from int8_tbl; q1 | q2 | r ------------------+-------------------+------------------- 123 | 456 | 456 123 | 4567890123456789 | 4567890123456789 4567890123456789 | 123 | 123 4567890123456789 | 4567890123456789 | 4567890123456789 4567890123456789 | -4567890123456789 | -4567890123456789 (5 rows) select *, (select r from (select q1 as q2) x, lateral (select q2 as r) y) from int8_tbl; q1 | q2 | r ------------------+-------------------+------------------ 123 | 456 | 123 123 | 4567890123456789 | 123 4567890123456789 | 123 | 4567890123456789 4567890123456789 | 4567890123456789 | 4567890123456789 4567890123456789 | -4567890123456789 | 4567890123456789 (5 rows) -- lateral with function in FROM select count(*) from tenk1 a, lateral generate_series(1,two) g; count ------- 5000 (1 row) explain (costs off) select count(*) from tenk1 a, lateral generate_series(1,two) g; QUERY PLAN ------------------------------------------------------ Aggregate -> Nested Loop -> Seq Scan on tenk1 a -> Memoize Cache Key: a.two Cache Mode: binary -> Function Scan on generate_series g (7 rows) explain (costs off) select count(*) from tenk1 a cross join lateral generate_series(1,two) g; QUERY PLAN ------------------------------------------------------ Aggregate -> Nested Loop -> Seq Scan on tenk1 a -> Memoize Cache Key: a.two Cache Mode: binary -> Function Scan on generate_series g (7 rows) -- don't need the explicit LATERAL keyword for functions explain (costs off) select count(*) from tenk1 a, generate_series(1,two) g; QUERY PLAN ------------------------------------------------------ Aggregate -> Nested Loop -> Seq Scan on tenk1 a -> Memoize Cache Key: a.two Cache Mode: binary -> Function Scan on generate_series g (7 rows) -- lateral with UNION ALL subselect explain (costs off) select * from generate_series(100,200) g, lateral (select * from int8_tbl a where g = q1 union all select * from int8_tbl b where g = q2) ss; QUERY PLAN ------------------------------------------ Nested Loop -> Function Scan on generate_series g -> Append -> Seq Scan on int8_tbl a Filter: (g.g = q1) -> Seq Scan on int8_tbl b Filter: (g.g = q2) (7 rows) select * from generate_series(100,200) g, lateral (select * from int8_tbl a where g = q1 union all select * from int8_tbl b where g = q2) ss; g | q1 | q2 -----+------------------+------------------ 123 | 123 | 456 123 | 123 | 4567890123456789 123 | 4567890123456789 | 123 (3 rows) -- lateral with VALUES explain (costs off) select count(*) from tenk1 a, tenk1 b join lateral (values(a.unique1)) ss(x) on b.unique2 = ss.x; QUERY PLAN ------------------------------------------------------------ Aggregate -> Merge Join Merge Cond: (a.unique1 = b.unique2) -> Index Only Scan using tenk1_unique1 on tenk1 a -> Index Only Scan using tenk1_unique2 on tenk1 b (5 rows) select count(*) from tenk1 a, tenk1 b join lateral (values(a.unique1)) ss(x) on b.unique2 = ss.x; count ------- 10000 (1 row) -- lateral with VALUES, no flattening possible explain (costs off) select count(*) from tenk1 a, tenk1 b join lateral (values(a.unique1),(-1)) ss(x) on b.unique2 = ss.x; QUERY PLAN ------------------------------------------------------------------ Aggregate -> Nested Loop -> Nested Loop -> Index Only Scan using tenk1_unique1 on tenk1 a -> Values Scan on "*VALUES*" -> Memoize Cache Key: "*VALUES*".column1 Cache Mode: logical -> Index Only Scan using tenk1_unique2 on tenk1 b Index Cond: (unique2 = "*VALUES*".column1) (10 rows) select count(*) from tenk1 a, tenk1 b join lateral (values(a.unique1),(-1)) ss(x) on b.unique2 = ss.x; count ------- 10000 (1 row) -- lateral injecting a strange outer join condition explain (costs off) select * from int8_tbl a, int8_tbl x left join lateral (select a.q1 from int4_tbl y) ss(z) on x.q2 = ss.z order by a.q1, a.q2, x.q1, x.q2, ss.z; QUERY PLAN ------------------------------------------------ Sort Sort Key: a.q1, a.q2, x.q1, x.q2, (a.q1) -> Nested Loop -> Seq Scan on int8_tbl a -> Hash Left Join Hash Cond: (x.q2 = (a.q1)) -> Seq Scan on int8_tbl x -> Hash -> Seq Scan on int4_tbl y (9 rows) select * from int8_tbl a, int8_tbl x left join lateral (select a.q1 from int4_tbl y) ss(z) on x.q2 = ss.z order by a.q1, a.q2, x.q1, x.q2, ss.z; q1 | q2 | q1 | q2 | z ------------------+-------------------+------------------+-------------------+------------------ 123 | 456 | 123 | 456 | 123 | 456 | 123 | 4567890123456789 | 123 | 456 | 4567890123456789 | -4567890123456789 | 123 | 456 | 4567890123456789 | 123 | 123 123 | 456 | 4567890123456789 | 123 | 123 123 | 456 | 4567890123456789 | 123 | 123 123 | 456 | 4567890123456789 | 123 | 123 123 | 456 | 4567890123456789 | 123 | 123 123 | 456 | 4567890123456789 | 4567890123456789 | 123 | 4567890123456789 | 123 | 456 | 123 | 4567890123456789 | 123 | 4567890123456789 | 123 | 4567890123456789 | 4567890123456789 | -4567890123456789 | 123 | 4567890123456789 | 4567890123456789 | 123 | 123 123 | 4567890123456789 | 4567890123456789 | 123 | 123 123 | 4567890123456789 | 4567890123456789 | 123 | 123 123 | 4567890123456789 | 4567890123456789 | 123 | 123 123 | 4567890123456789 | 4567890123456789 | 123 | 123 123 | 4567890123456789 | 4567890123456789 | 4567890123456789 | 4567890123456789 | -4567890123456789 | 123 | 456 | 4567890123456789 | -4567890123456789 | 123 | 4567890123456789 | 4567890123456789 4567890123456789 | -4567890123456789 | 123 | 4567890123456789 | 4567890123456789 4567890123456789 | -4567890123456789 | 123 | 4567890123456789 | 4567890123456789 4567890123456789 | -4567890123456789 | 123 | 4567890123456789 | 4567890123456789 4567890123456789 | -4567890123456789 | 123 | 4567890123456789 | 4567890123456789 4567890123456789 | -4567890123456789 | 4567890123456789 | -4567890123456789 | 4567890123456789 | -4567890123456789 | 4567890123456789 | 123 | 4567890123456789 | -4567890123456789 | 4567890123456789 | 4567890123456789 | 4567890123456789 4567890123456789 | -4567890123456789 | 4567890123456789 | 4567890123456789 | 4567890123456789 4567890123456789 | -4567890123456789 | 4567890123456789 | 4567890123456789 | 4567890123456789 4567890123456789 | -4567890123456789 | 4567890123456789 | 4567890123456789 | 4567890123456789 4567890123456789 | -4567890123456789 | 4567890123456789 | 4567890123456789 | 4567890123456789 4567890123456789 | 123 | 123 | 456 | 4567890123456789 | 123 | 123 | 4567890123456789 | 4567890123456789 4567890123456789 | 123 | 123 | 4567890123456789 | 4567890123456789 4567890123456789 | 123 | 123 | 4567890123456789 | 4567890123456789 4567890123456789 | 123 | 123 | 4567890123456789 | 4567890123456789 4567890123456789 | 123 | 123 | 4567890123456789 | 4567890123456789 4567890123456789 | 123 | 4567890123456789 | -4567890123456789 | 4567890123456789 | 123 | 4567890123456789 | 123 | 4567890123456789 | 123 | 4567890123456789 | 4567890123456789 | 4567890123456789 4567890123456789 | 123 | 4567890123456789 | 4567890123456789 | 4567890123456789 4567890123456789 | 123 | 4567890123456789 | 4567890123456789 | 4567890123456789 4567890123456789 | 123 | 4567890123456789 | 4567890123456789 | 4567890123456789 4567890123456789 | 123 | 4567890123456789 | 4567890123456789 | 4567890123456789 4567890123456789 | 4567890123456789 | 123 | 456 | 4567890123456789 | 4567890123456789 | 123 | 4567890123456789 | 4567890123456789 4567890123456789 | 4567890123456789 | 123 | 4567890123456789 | 4567890123456789 4567890123456789 | 4567890123456789 | 123 | 4567890123456789 | 4567890123456789 4567890123456789 | 4567890123456789 | 123 | 4567890123456789 | 4567890123456789 4567890123456789 | 4567890123456789 | 123 | 4567890123456789 | 4567890123456789 4567890123456789 | 4567890123456789 | 4567890123456789 | -4567890123456789 | 4567890123456789 | 4567890123456789 | 4567890123456789 | 123 | 4567890123456789 | 4567890123456789 | 4567890123456789 | 4567890123456789 | 4567890123456789 4567890123456789 | 4567890123456789 | 4567890123456789 | 4567890123456789 | 4567890123456789 4567890123456789 | 4567890123456789 | 4567890123456789 | 4567890123456789 | 4567890123456789 4567890123456789 | 4567890123456789 | 4567890123456789 | 4567890123456789 | 4567890123456789 4567890123456789 | 4567890123456789 | 4567890123456789 | 4567890123456789 | 4567890123456789 (57 rows) -- lateral reference to a join alias variable select * from (select f1/2 as x from int4_tbl) ss1 join int4_tbl i4 on x = f1, lateral (select x) ss2(y); x | f1 | y ---+----+--- 0 | 0 | 0 (1 row) select * from (select f1 as x from int4_tbl) ss1 join int4_tbl i4 on x = f1, lateral (values(x)) ss2(y); x | f1 | y -------------+-------------+------------- 0 | 0 | 0 123456 | 123456 | 123456 -123456 | -123456 | -123456 2147483647 | 2147483647 | 2147483647 -2147483647 | -2147483647 | -2147483647 (5 rows) select * from ((select f1/2 as x from int4_tbl) ss1 join int4_tbl i4 on x = f1) j, lateral (select x) ss2(y); x | f1 | y ---+----+--- 0 | 0 | 0 (1 row) -- lateral references requiring pullup select * from (values(1)) x(lb), lateral generate_series(lb,4) x4; lb | x4 ----+---- 1 | 1 1 | 2 1 | 3 1 | 4 (4 rows) select * from (select f1/1000000000 from int4_tbl) x(lb), lateral generate_series(lb,4) x4; lb | x4 ----+---- 0 | 0 0 | 1 0 | 2 0 | 3 0 | 4 0 | 0 0 | 1 0 | 2 0 | 3 0 | 4 0 | 0 0 | 1 0 | 2 0 | 3 0 | 4 2 | 2 2 | 3 2 | 4 -2 | -2 -2 | -1 -2 | 0 -2 | 1 -2 | 2 -2 | 3 -2 | 4 (25 rows) select * from (values(1)) x(lb), lateral (values(lb)) y(lbcopy); lb | lbcopy ----+-------- 1 | 1 (1 row) select * from (values(1)) x(lb), lateral (select lb from int4_tbl) y(lbcopy); lb | lbcopy ----+-------- 1 | 1 1 | 1 1 | 1 1 | 1 1 | 1 (5 rows) select * from int8_tbl x left join (select q1,coalesce(q2,0) q2 from int8_tbl) y on x.q2 = y.q1, lateral (values(x.q1,y.q1,y.q2)) v(xq1,yq1,yq2); q1 | q2 | q1 | q2 | xq1 | yq1 | yq2 ------------------+-------------------+------------------+-------------------+------------------+------------------+------------------- 123 | 456 | | | 123 | | 123 | 4567890123456789 | 4567890123456789 | -4567890123456789 | 123 | 4567890123456789 | -4567890123456789 123 | 4567890123456789 | 4567890123456789 | 4567890123456789 | 123 | 4567890123456789 | 4567890123456789 123 | 4567890123456789 | 4567890123456789 | 123 | 123 | 4567890123456789 | 123 4567890123456789 | 123 | 123 | 4567890123456789 | 4567890123456789 | 123 | 4567890123456789 4567890123456789 | 123 | 123 | 456 | 4567890123456789 | 123 | 456 4567890123456789 | 4567890123456789 | 4567890123456789 | -4567890123456789 | 4567890123456789 | 4567890123456789 | -4567890123456789 4567890123456789 | 4567890123456789 | 4567890123456789 | 4567890123456789 | 4567890123456789 | 4567890123456789 | 4567890123456789 4567890123456789 | 4567890123456789 | 4567890123456789 | 123 | 4567890123456789 | 4567890123456789 | 123 4567890123456789 | -4567890123456789 | | | 4567890123456789 | | (10 rows) select * from int8_tbl x left join (select q1,coalesce(q2,0) q2 from int8_tbl) y on x.q2 = y.q1, lateral (select x.q1,y.q1,y.q2) v(xq1,yq1,yq2); q1 | q2 | q1 | q2 | xq1 | yq1 | yq2 ------------------+-------------------+------------------+-------------------+------------------+------------------+------------------- 123 | 456 | | | 123 | | 123 | 4567890123456789 | 4567890123456789 | -4567890123456789 | 123 | 4567890123456789 | -4567890123456789 123 | 4567890123456789 | 4567890123456789 | 4567890123456789 | 123 | 4567890123456789 | 4567890123456789 123 | 4567890123456789 | 4567890123456789 | 123 | 123 | 4567890123456789 | 123 4567890123456789 | 123 | 123 | 4567890123456789 | 4567890123456789 | 123 | 4567890123456789 4567890123456789 | 123 | 123 | 456 | 4567890123456789 | 123 | 456 4567890123456789 | 4567890123456789 | 4567890123456789 | -4567890123456789 | 4567890123456789 | 4567890123456789 | -4567890123456789 4567890123456789 | 4567890123456789 | 4567890123456789 | 4567890123456789 | 4567890123456789 | 4567890123456789 | 4567890123456789 4567890123456789 | 4567890123456789 | 4567890123456789 | 123 | 4567890123456789 | 4567890123456789 | 123 4567890123456789 | -4567890123456789 | | | 4567890123456789 | | (10 rows) select x.* from int8_tbl x left join (select q1,coalesce(q2,0) q2 from int8_tbl) y on x.q2 = y.q1, lateral (select x.q1,y.q1,y.q2) v(xq1,yq1,yq2); q1 | q2 ------------------+------------------- 123 | 456 123 | 4567890123456789 123 | 4567890123456789 123 | 4567890123456789 4567890123456789 | 123 4567890123456789 | 123 4567890123456789 | 4567890123456789 4567890123456789 | 4567890123456789 4567890123456789 | 4567890123456789 4567890123456789 | -4567890123456789 (10 rows) select v.* from (int8_tbl x left join (select q1,coalesce(q2,0) q2 from int8_tbl) y on x.q2 = y.q1) left join int4_tbl z on z.f1 = x.q2, lateral (select x.q1,y.q1 union all select x.q2,y.q2) v(vx,vy); vx | vy -------------------+------------------- 123 | 456 | 123 | 4567890123456789 4567890123456789 | -4567890123456789 123 | 4567890123456789 4567890123456789 | 4567890123456789 123 | 4567890123456789 4567890123456789 | 123 4567890123456789 | 123 123 | 4567890123456789 4567890123456789 | 123 123 | 456 4567890123456789 | 4567890123456789 4567890123456789 | -4567890123456789 4567890123456789 | 4567890123456789 4567890123456789 | 4567890123456789 4567890123456789 | 4567890123456789 4567890123456789 | 123 4567890123456789 | -4567890123456789 | (20 rows) select v.* from (int8_tbl x left join (select q1,(select coalesce(q2,0)) q2 from int8_tbl) y on x.q2 = y.q1) left join int4_tbl z on z.f1 = x.q2, lateral (select x.q1,y.q1 union all select x.q2,y.q2) v(vx,vy); vx | vy -------------------+------------------- 4567890123456789 | 123 123 | 456 4567890123456789 | 123 123 | 4567890123456789 4567890123456789 | 4567890123456789 4567890123456789 | 123 123 | 4567890123456789 4567890123456789 | 123 4567890123456789 | 4567890123456789 4567890123456789 | 4567890123456789 123 | 4567890123456789 4567890123456789 | 4567890123456789 4567890123456789 | 4567890123456789 4567890123456789 | -4567890123456789 123 | 4567890123456789 4567890123456789 | -4567890123456789 123 | 456 | 4567890123456789 | -4567890123456789 | (20 rows) select v.* from (int8_tbl x left join (select q1,(select coalesce(q2,0)) q2 from int8_tbl) y on x.q2 = y.q1) left join int4_tbl z on z.f1 = x.q2, lateral (select x.q1,y.q1 from onerow union all select x.q2,y.q2 from onerow) v(vx,vy); vx | vy -------------------+------------------- 4567890123456789 | 123 123 | 456 4567890123456789 | 123 123 | 4567890123456789 4567890123456789 | 4567890123456789 4567890123456789 | 123 123 | 4567890123456789 4567890123456789 | 123 4567890123456789 | 4567890123456789 4567890123456789 | 4567890123456789 123 | 4567890123456789 4567890123456789 | 4567890123456789 4567890123456789 | 4567890123456789 4567890123456789 | -4567890123456789 123 | 4567890123456789 4567890123456789 | -4567890123456789 123 | 456 | 4567890123456789 | -4567890123456789 | (20 rows) explain (verbose, costs off) select * from int8_tbl a left join lateral (select *, a.q2 as x from int8_tbl b) ss on a.q2 = ss.q1; QUERY PLAN ------------------------------------------ Nested Loop Left Join Output: a.q1, a.q2, b.q1, b.q2, (a.q2) -> Seq Scan on public.int8_tbl a Output: a.q1, a.q2 -> Seq Scan on public.int8_tbl b Output: b.q1, b.q2, a.q2 Filter: (a.q2 = b.q1) (7 rows) select * from int8_tbl a left join lateral (select *, a.q2 as x from int8_tbl b) ss on a.q2 = ss.q1; q1 | q2 | q1 | q2 | x ------------------+-------------------+------------------+-------------------+------------------ 123 | 456 | | | 123 | 4567890123456789 | 4567890123456789 | 123 | 4567890123456789 123 | 4567890123456789 | 4567890123456789 | 4567890123456789 | 4567890123456789 123 | 4567890123456789 | 4567890123456789 | -4567890123456789 | 4567890123456789 4567890123456789 | 123 | 123 | 456 | 123 4567890123456789 | 123 | 123 | 4567890123456789 | 123 4567890123456789 | 4567890123456789 | 4567890123456789 | 123 | 4567890123456789 4567890123456789 | 4567890123456789 | 4567890123456789 | 4567890123456789 | 4567890123456789 4567890123456789 | 4567890123456789 | 4567890123456789 | -4567890123456789 | 4567890123456789 4567890123456789 | -4567890123456789 | | | (10 rows) explain (verbose, costs off) select * from int8_tbl a left join lateral (select *, coalesce(a.q2, 42) as x from int8_tbl b) ss on a.q2 = ss.q1; QUERY PLAN ------------------------------------------------------------------ Nested Loop Left Join Output: a.q1, a.q2, b.q1, b.q2, (COALESCE(a.q2, '42'::bigint)) -> Seq Scan on public.int8_tbl a Output: a.q1, a.q2 -> Seq Scan on public.int8_tbl b Output: b.q1, b.q2, COALESCE(a.q2, '42'::bigint) Filter: (a.q2 = b.q1) (7 rows) select * from int8_tbl a left join lateral (select *, coalesce(a.q2, 42) as x from int8_tbl b) ss on a.q2 = ss.q1; q1 | q2 | q1 | q2 | x ------------------+-------------------+------------------+-------------------+------------------ 123 | 456 | | | 123 | 4567890123456789 | 4567890123456789 | 123 | 4567890123456789 123 | 4567890123456789 | 4567890123456789 | 4567890123456789 | 4567890123456789 123 | 4567890123456789 | 4567890123456789 | -4567890123456789 | 4567890123456789 4567890123456789 | 123 | 123 | 456 | 123 4567890123456789 | 123 | 123 | 4567890123456789 | 123 4567890123456789 | 4567890123456789 | 4567890123456789 | 123 | 4567890123456789 4567890123456789 | 4567890123456789 | 4567890123456789 | 4567890123456789 | 4567890123456789 4567890123456789 | 4567890123456789 | 4567890123456789 | -4567890123456789 | 4567890123456789 4567890123456789 | -4567890123456789 | | | (10 rows) -- lateral can result in join conditions appearing below their -- real semantic level explain (verbose, costs off) select * from int4_tbl i left join lateral (select * from int2_tbl j where i.f1 = j.f1) k on true; QUERY PLAN ------------------------------------------- Hash Left Join Output: i.f1, j.f1 Hash Cond: (i.f1 = j.f1) -> Seq Scan on public.int4_tbl i Output: i.f1 -> Hash Output: j.f1 -> Seq Scan on public.int2_tbl j Output: j.f1 (9 rows) select * from int4_tbl i left join lateral (select * from int2_tbl j where i.f1 = j.f1) k on true; f1 | f1 -------------+---- 0 | 0 123456 | -123456 | 2147483647 | -2147483647 | (5 rows) explain (verbose, costs off) select * from int4_tbl i left join lateral (select coalesce(i) from int2_tbl j where i.f1 = j.f1) k on true; QUERY PLAN ------------------------------------- Nested Loop Left Join Output: i.f1, (COALESCE(i.*)) -> Seq Scan on public.int4_tbl i Output: i.f1, i.* -> Seq Scan on public.int2_tbl j Output: j.f1, COALESCE(i.*) Filter: (i.f1 = j.f1) (7 rows) select * from int4_tbl i left join lateral (select coalesce(i) from int2_tbl j where i.f1 = j.f1) k on true; f1 | coalesce -------------+---------- 0 | (0) 123456 | -123456 | 2147483647 | -2147483647 | (5 rows) explain (verbose, costs off) select * from int4_tbl a, lateral ( select * from int4_tbl b left join int8_tbl c on (b.f1 = q1 and a.f1 = q2) ) ss; QUERY PLAN ------------------------------------------------- Nested Loop Output: a.f1, b.f1, c.q1, c.q2 -> Seq Scan on public.int4_tbl a Output: a.f1 -> Hash Left Join Output: b.f1, c.q1, c.q2 Hash Cond: (b.f1 = c.q1) -> Seq Scan on public.int4_tbl b Output: b.f1 -> Hash Output: c.q1, c.q2 -> Seq Scan on public.int8_tbl c Output: c.q1, c.q2 Filter: (a.f1 = c.q2) (14 rows) select * from int4_tbl a, lateral ( select * from int4_tbl b left join int8_tbl c on (b.f1 = q1 and a.f1 = q2) ) ss; f1 | f1 | q1 | q2 -------------+-------------+----+---- 0 | 0 | | 0 | 123456 | | 0 | -123456 | | 0 | 2147483647 | | 0 | -2147483647 | | 123456 | 0 | | 123456 | 123456 | | 123456 | -123456 | | 123456 | 2147483647 | | 123456 | -2147483647 | | -123456 | 0 | | -123456 | 123456 | | -123456 | -123456 | | -123456 | 2147483647 | | -123456 | -2147483647 | | 2147483647 | 0 | | 2147483647 | 123456 | | 2147483647 | -123456 | | 2147483647 | 2147483647 | | 2147483647 | -2147483647 | | -2147483647 | 0 | | -2147483647 | 123456 | | -2147483647 | -123456 | | -2147483647 | 2147483647 | | -2147483647 | -2147483647 | | (25 rows) -- lateral reference in a PlaceHolderVar evaluated at join level explain (verbose, costs off) select * from int8_tbl a left join lateral (select b.q1 as bq1, c.q1 as cq1, least(a.q1,b.q1,c.q1) from int8_tbl b cross join int8_tbl c) ss on a.q2 = ss.bq1; QUERY PLAN ------------------------------------------------------------- Nested Loop Left Join Output: a.q1, a.q2, b.q1, c.q1, (LEAST(a.q1, b.q1, c.q1)) -> Seq Scan on public.int8_tbl a Output: a.q1, a.q2 -> Nested Loop Output: b.q1, c.q1, LEAST(a.q1, b.q1, c.q1) -> Seq Scan on public.int8_tbl b Output: b.q1, b.q2 Filter: (a.q2 = b.q1) -> Seq Scan on public.int8_tbl c Output: c.q1, c.q2 (11 rows) select * from int8_tbl a left join lateral (select b.q1 as bq1, c.q1 as cq1, least(a.q1,b.q1,c.q1) from int8_tbl b cross join int8_tbl c) ss on a.q2 = ss.bq1; q1 | q2 | bq1 | cq1 | least ------------------+-------------------+------------------+------------------+------------------ 123 | 456 | | | 123 | 4567890123456789 | 4567890123456789 | 123 | 123 123 | 4567890123456789 | 4567890123456789 | 123 | 123 123 | 4567890123456789 | 4567890123456789 | 4567890123456789 | 123 123 | 4567890123456789 | 4567890123456789 | 4567890123456789 | 123 123 | 4567890123456789 | 4567890123456789 | 4567890123456789 | 123 123 | 4567890123456789 | 4567890123456789 | 123 | 123 123 | 4567890123456789 | 4567890123456789 | 123 | 123 123 | 4567890123456789 | 4567890123456789 | 4567890123456789 | 123 123 | 4567890123456789 | 4567890123456789 | 4567890123456789 | 123 123 | 4567890123456789 | 4567890123456789 | 4567890123456789 | 123 123 | 4567890123456789 | 4567890123456789 | 123 | 123 123 | 4567890123456789 | 4567890123456789 | 123 | 123 123 | 4567890123456789 | 4567890123456789 | 4567890123456789 | 123 123 | 4567890123456789 | 4567890123456789 | 4567890123456789 | 123 123 | 4567890123456789 | 4567890123456789 | 4567890123456789 | 123 4567890123456789 | 123 | 123 | 123 | 123 4567890123456789 | 123 | 123 | 123 | 123 4567890123456789 | 123 | 123 | 4567890123456789 | 123 4567890123456789 | 123 | 123 | 4567890123456789 | 123 4567890123456789 | 123 | 123 | 4567890123456789 | 123 4567890123456789 | 123 | 123 | 123 | 123 4567890123456789 | 123 | 123 | 123 | 123 4567890123456789 | 123 | 123 | 4567890123456789 | 123 4567890123456789 | 123 | 123 | 4567890123456789 | 123 4567890123456789 | 123 | 123 | 4567890123456789 | 123 4567890123456789 | 4567890123456789 | 4567890123456789 | 123 | 123 4567890123456789 | 4567890123456789 | 4567890123456789 | 123 | 123 4567890123456789 | 4567890123456789 | 4567890123456789 | 4567890123456789 | 4567890123456789 4567890123456789 | 4567890123456789 | 4567890123456789 | 4567890123456789 | 4567890123456789 4567890123456789 | 4567890123456789 | 4567890123456789 | 4567890123456789 | 4567890123456789 4567890123456789 | 4567890123456789 | 4567890123456789 | 123 | 123 4567890123456789 | 4567890123456789 | 4567890123456789 | 123 | 123 4567890123456789 | 4567890123456789 | 4567890123456789 | 4567890123456789 | 4567890123456789 4567890123456789 | 4567890123456789 | 4567890123456789 | 4567890123456789 | 4567890123456789 4567890123456789 | 4567890123456789 | 4567890123456789 | 4567890123456789 | 4567890123456789 4567890123456789 | 4567890123456789 | 4567890123456789 | 123 | 123 4567890123456789 | 4567890123456789 | 4567890123456789 | 123 | 123 4567890123456789 | 4567890123456789 | 4567890123456789 | 4567890123456789 | 4567890123456789 4567890123456789 | 4567890123456789 | 4567890123456789 | 4567890123456789 | 4567890123456789 4567890123456789 | 4567890123456789 | 4567890123456789 | 4567890123456789 | 4567890123456789 4567890123456789 | -4567890123456789 | | | (42 rows) -- case requiring nested PlaceHolderVars explain (verbose, costs off) select * from int8_tbl c left join ( int8_tbl a left join (select q1, coalesce(q2,42) as x from int8_tbl b) ss1 on a.q2 = ss1.q1 cross join lateral (select q1, coalesce(ss1.x,q2) as y from int8_tbl d) ss2 ) on c.q2 = ss2.q1, lateral (select ss2.y offset 0) ss3; QUERY PLAN ------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------ Nested Loop Output: c.q1, c.q2, a.q1, a.q2, b.q1, (COALESCE(b.q2, '42'::bigint)), d.q1, (COALESCE((COALESCE(b.q2, '42'::bigint)), d.q2)), ((COALESCE((COALESCE(b.q2, '42'::bigint)), d.q2))) -> Hash Right Join Output: c.q1, c.q2, a.q1, a.q2, b.q1, (COALESCE(b.q2, '42'::bigint)), d.q1, (COALESCE((COALESCE(b.q2, '42'::bigint)), d.q2)) Hash Cond: (d.q1 = c.q2) -> Nested Loop Output: a.q1, a.q2, b.q1, (COALESCE(b.q2, '42'::bigint)), d.q1, (COALESCE((COALESCE(b.q2, '42'::bigint)), d.q2)) -> Hash Left Join Output: a.q1, a.q2, b.q1, (COALESCE(b.q2, '42'::bigint)) Hash Cond: (a.q2 = b.q1) -> Seq Scan on public.int8_tbl a Output: a.q1, a.q2 -> Hash Output: b.q1, (COALESCE(b.q2, '42'::bigint)) -> Seq Scan on public.int8_tbl b Output: b.q1, COALESCE(b.q2, '42'::bigint) -> Seq Scan on public.int8_tbl d Output: d.q1, COALESCE((COALESCE(b.q2, '42'::bigint)), d.q2) -> Hash Output: c.q1, c.q2 -> Seq Scan on public.int8_tbl c Output: c.q1, c.q2 -> Result Output: (COALESCE((COALESCE(b.q2, '42'::bigint)), d.q2)) (24 rows) -- case that breaks the old ph_may_need optimization explain (verbose, costs off) select c.*,a.*,ss1.q1,ss2.q1,ss3.* from int8_tbl c left join ( int8_tbl a left join (select q1, coalesce(q2,f1) as x from int8_tbl b, int4_tbl b2 where q1 < f1) ss1 on a.q2 = ss1.q1 cross join lateral (select q1, coalesce(ss1.x,q2) as y from int8_tbl d) ss2 ) on c.q2 = ss2.q1, lateral (select * from int4_tbl i where ss2.y > f1) ss3; QUERY PLAN --------------------------------------------------------------------------------------------------------- Nested Loop Output: c.q1, c.q2, a.q1, a.q2, b.q1, d.q1, i.f1 Join Filter: ((COALESCE((COALESCE(b.q2, (b2.f1)::bigint)), d.q2)) > i.f1) -> Hash Right Join Output: c.q1, c.q2, a.q1, a.q2, b.q1, d.q1, (COALESCE((COALESCE(b.q2, (b2.f1)::bigint)), d.q2)) Hash Cond: (d.q1 = c.q2) -> Nested Loop Output: a.q1, a.q2, b.q1, d.q1, (COALESCE((COALESCE(b.q2, (b2.f1)::bigint)), d.q2)) -> Hash Right Join Output: a.q1, a.q2, b.q1, (COALESCE(b.q2, (b2.f1)::bigint)) Hash Cond: (b.q1 = a.q2) -> Nested Loop Output: b.q1, COALESCE(b.q2, (b2.f1)::bigint) Join Filter: (b.q1 < b2.f1) -> Seq Scan on public.int8_tbl b Output: b.q1, b.q2 -> Materialize Output: b2.f1 -> Seq Scan on public.int4_tbl b2 Output: b2.f1 -> Hash Output: a.q1, a.q2 -> Seq Scan on public.int8_tbl a Output: a.q1, a.q2 -> Seq Scan on public.int8_tbl d Output: d.q1, COALESCE((COALESCE(b.q2, (b2.f1)::bigint)), d.q2) -> Hash Output: c.q1, c.q2 -> Seq Scan on public.int8_tbl c Output: c.q1, c.q2 -> Materialize Output: i.f1 -> Seq Scan on public.int4_tbl i Output: i.f1 (34 rows) -- check processing of postponed quals (bug #9041) explain (verbose, costs off) select * from (select 1 as x offset 0) x cross join (select 2 as y offset 0) y left join lateral ( select * from (select 3 as z offset 0) z where z.z = x.x ) zz on zz.z = y.y; QUERY PLAN ---------------------------------------------- Nested Loop Left Join Output: (1), (2), (3) Join Filter: (((3) = (1)) AND ((3) = (2))) -> Nested Loop Output: (1), (2) -> Result Output: 1 -> Result Output: 2 -> Result Output: 3 (11 rows) -- a new postponed-quals issue (bug #17768) explain (costs off) select * from int4_tbl t1, lateral (select * from int4_tbl t2 inner join int4_tbl t3 on t1.f1 = 1 inner join (int4_tbl t4 left join int4_tbl t5 on true) on true) ss; QUERY PLAN ------------------------------------------------- Nested Loop Left Join -> Nested Loop -> Nested Loop -> Nested Loop -> Seq Scan on int4_tbl t1 Filter: (f1 = 1) -> Seq Scan on int4_tbl t2 -> Materialize -> Seq Scan on int4_tbl t3 -> Materialize -> Seq Scan on int4_tbl t4 -> Materialize -> Seq Scan on int4_tbl t5 (13 rows) -- check dummy rels with lateral references (bug #15694) explain (verbose, costs off) select * from int8_tbl i8 left join lateral (select *, i8.q2 from int4_tbl where false) ss on true; QUERY PLAN -------------------------------------- Nested Loop Left Join Output: i8.q1, i8.q2, f1, (i8.q2) Join Filter: false -> Seq Scan on public.int8_tbl i8 Output: i8.q1, i8.q2 -> Result Output: f1, i8.q2 One-Time Filter: false (8 rows) explain (verbose, costs off) select * from int8_tbl i8 left join lateral (select *, i8.q2 from int4_tbl i1, int4_tbl i2 where false) ss on true; QUERY PLAN ----------------------------------------- Nested Loop Left Join Output: i8.q1, i8.q2, f1, f1, (i8.q2) -> Seq Scan on public.int8_tbl i8 Output: i8.q1, i8.q2 -> Result Output: f1, f1, i8.q2 One-Time Filter: false (7 rows) -- check handling of nested appendrels inside LATERAL select * from ((select 2 as v) union all (select 3 as v)) as q1 cross join lateral ((select * from ((select 4 as v) union all (select 5 as v)) as q3) union all (select q1.v) ) as q2; v | v ---+--- 2 | 4 2 | 5 2 | 2 3 | 4 3 | 5 3 | 3 (6 rows) -- check the number of columns specified SELECT * FROM (int8_tbl i cross join int4_tbl j) ss(a,b,c,d); ERROR: join expression "ss" has 3 columns available but 4 columns specified -- check we don't try to do a unique-ified semijoin with LATERAL explain (verbose, costs off) select * from (values (0,9998), (1,1000)) v(id,x), lateral (select f1 from int4_tbl where f1 = any (select unique1 from tenk1 where unique2 = v.x offset 0)) ss; QUERY PLAN ---------------------------------------------------------------------- Nested Loop Output: "*VALUES*".column1, "*VALUES*".column2, int4_tbl.f1 -> Values Scan on "*VALUES*" Output: "*VALUES*".column1, "*VALUES*".column2 -> Nested Loop Semi Join Output: int4_tbl.f1 Join Filter: (int4_tbl.f1 = tenk1.unique1) -> Seq Scan on public.int4_tbl Output: int4_tbl.f1 -> Materialize Output: tenk1.unique1 -> Index Scan using tenk1_unique2 on public.tenk1 Output: tenk1.unique1 Index Cond: (tenk1.unique2 = "*VALUES*".column2) (14 rows) select * from (values (0,9998), (1,1000)) v(id,x), lateral (select f1 from int4_tbl where f1 = any (select unique1 from tenk1 where unique2 = v.x offset 0)) ss; id | x | f1 ----+------+---- 0 | 9998 | 0 (1 row) -- check proper extParam/allParam handling (this isn't exactly a LATERAL issue, -- but we can make the test case much more compact with LATERAL) explain (verbose, costs off) select * from (values (0), (1)) v(id), lateral (select * from int8_tbl t1, lateral (select * from (select * from int8_tbl t2 where q1 = any (select q2 from int8_tbl t3 where q2 = (select greatest(t1.q1,t2.q2)) and (select v.id=0)) offset 0) ss2) ss where t1.q1 = ss.q2) ss0; QUERY PLAN ---------------------------------------------------------------------- Nested Loop Output: "*VALUES*".column1, t1.q1, t1.q2, ss2.q1, ss2.q2 -> Seq Scan on public.int8_tbl t1 Output: t1.q1, t1.q2 -> Nested Loop Output: "*VALUES*".column1, ss2.q1, ss2.q2 -> Values Scan on "*VALUES*" Output: "*VALUES*".column1 -> Subquery Scan on ss2 Output: ss2.q1, ss2.q2 Filter: (t1.q1 = ss2.q2) -> Seq Scan on public.int8_tbl t2 Output: t2.q1, t2.q2 Filter: (SubPlan 3) SubPlan 3 -> Result Output: t3.q2 One-Time Filter: $4 InitPlan 1 (returns $2) -> Result Output: GREATEST(t1.q1, t2.q2) InitPlan 2 (returns $4) -> Result Output: ("*VALUES*".column1 = 0) -> Seq Scan on public.int8_tbl t3 Output: t3.q1, t3.q2 Filter: (t3.q2 = $2) (27 rows) select * from (values (0), (1)) v(id), lateral (select * from int8_tbl t1, lateral (select * from (select * from int8_tbl t2 where q1 = any (select q2 from int8_tbl t3 where q2 = (select greatest(t1.q1,t2.q2)) and (select v.id=0)) offset 0) ss2) ss where t1.q1 = ss.q2) ss0; id | q1 | q2 | q1 | q2 ----+------------------+-------------------+------------------+------------------ 0 | 4567890123456789 | 123 | 4567890123456789 | 4567890123456789 0 | 4567890123456789 | 4567890123456789 | 4567890123456789 | 4567890123456789 0 | 4567890123456789 | -4567890123456789 | 4567890123456789 | 4567890123456789 (3 rows) -- test some error cases where LATERAL should have been used but wasn't select f1,g from int4_tbl a, (select f1 as g) ss; ERROR: column "f1" does not exist LINE 1: select f1,g from int4_tbl a, (select f1 as g) ss; ^ DETAIL: There is a column named "f1" in table "a", but it cannot be referenced from this part of the query. HINT: To reference that column, you must mark this subquery with LATERAL. select f1,g from int4_tbl a, (select a.f1 as g) ss; ERROR: invalid reference to FROM-clause entry for table "a" LINE 1: select f1,g from int4_tbl a, (select a.f1 as g) ss; ^ DETAIL: There is an entry for table "a", but it cannot be referenced from this part of the query. HINT: To reference that table, you must mark this subquery with LATERAL. select f1,g from int4_tbl a cross join (select f1 as g) ss; ERROR: column "f1" does not exist LINE 1: select f1,g from int4_tbl a cross join (select f1 as g) ss; ^ DETAIL: There is a column named "f1" in table "a", but it cannot be referenced from this part of the query. HINT: To reference that column, you must mark this subquery with LATERAL. select f1,g from int4_tbl a cross join (select a.f1 as g) ss; ERROR: invalid reference to FROM-clause entry for table "a" LINE 1: select f1,g from int4_tbl a cross join (select a.f1 as g) ss... ^ DETAIL: There is an entry for table "a", but it cannot be referenced from this part of the query. HINT: To reference that table, you must mark this subquery with LATERAL. -- SQL:2008 says the left table is in scope but illegal to access here select f1,g from int4_tbl a right join lateral generate_series(0, a.f1) g on true; ERROR: invalid reference to FROM-clause entry for table "a" LINE 1: ... int4_tbl a right join lateral generate_series(0, a.f1) g on... ^ DETAIL: The combining JOIN type must be INNER or LEFT for a LATERAL reference. select f1,g from int4_tbl a full join lateral generate_series(0, a.f1) g on true; ERROR: invalid reference to FROM-clause entry for table "a" LINE 1: ...m int4_tbl a full join lateral generate_series(0, a.f1) g on... ^ DETAIL: The combining JOIN type must be INNER or LEFT for a LATERAL reference. -- check we complain about ambiguous table references select * from int8_tbl x cross join (int4_tbl x cross join lateral (select x.f1) ss); ERROR: table reference "x" is ambiguous LINE 2: ...cross join (int4_tbl x cross join lateral (select x.f1) ss); ^ -- LATERAL can be used to put an aggregate into the FROM clause of its query select 1 from tenk1 a, lateral (select max(a.unique1) from int4_tbl b) ss; ERROR: aggregate functions are not allowed in FROM clause of their own query level LINE 1: select 1 from tenk1 a, lateral (select max(a.unique1) from i... ^ -- check behavior of LATERAL in UPDATE/DELETE create temp table xx1 as select f1 as x1, -f1 as x2 from int4_tbl; -- error, can't do this: update xx1 set x2 = f1 from (select * from int4_tbl where f1 = x1) ss; ERROR: column "x1" does not exist LINE 1: ... set x2 = f1 from (select * from int4_tbl where f1 = x1) ss; ^ DETAIL: There is a column named "x1" in table "xx1", but it cannot be referenced from this part of the query. update xx1 set x2 = f1 from (select * from int4_tbl where f1 = xx1.x1) ss; ERROR: invalid reference to FROM-clause entry for table "xx1" LINE 1: ...t x2 = f1 from (select * from int4_tbl where f1 = xx1.x1) ss... ^ DETAIL: There is an entry for table "xx1", but it cannot be referenced from this part of the query. -- can't do it even with LATERAL: update xx1 set x2 = f1 from lateral (select * from int4_tbl where f1 = x1) ss; ERROR: invalid reference to FROM-clause entry for table "xx1" LINE 1: ...= f1 from lateral (select * from int4_tbl where f1 = x1) ss; ^ HINT: There is an entry for table "xx1", but it cannot be referenced from this part of the query. -- we might in future allow something like this, but for now it's an error: update xx1 set x2 = f1 from xx1, lateral (select * from int4_tbl where f1 = x1) ss; ERROR: table name "xx1" specified more than once -- also errors: delete from xx1 using (select * from int4_tbl where f1 = x1) ss; ERROR: column "x1" does not exist LINE 1: ...te from xx1 using (select * from int4_tbl where f1 = x1) ss; ^ DETAIL: There is a column named "x1" in table "xx1", but it cannot be referenced from this part of the query. delete from xx1 using (select * from int4_tbl where f1 = xx1.x1) ss; ERROR: invalid reference to FROM-clause entry for table "xx1" LINE 1: ...from xx1 using (select * from int4_tbl where f1 = xx1.x1) ss... ^ DETAIL: There is an entry for table "xx1", but it cannot be referenced from this part of the query. delete from xx1 using lateral (select * from int4_tbl where f1 = x1) ss; ERROR: invalid reference to FROM-clause entry for table "xx1" LINE 1: ...xx1 using lateral (select * from int4_tbl where f1 = x1) ss; ^ HINT: There is an entry for table "xx1", but it cannot be referenced from this part of the query. -- -- test LATERAL reference propagation down a multi-level inheritance hierarchy -- produced for a multi-level partitioned table hierarchy. -- create table join_pt1 (a int, b int, c varchar) partition by range(a); create table join_pt1p1 partition of join_pt1 for values from (0) to (100) partition by range(b); create table join_pt1p2 partition of join_pt1 for values from (100) to (200); create table join_pt1p1p1 partition of join_pt1p1 for values from (0) to (100); insert into join_pt1 values (1, 1, 'x'), (101, 101, 'y'); create table join_ut1 (a int, b int, c varchar); insert into join_ut1 values (101, 101, 'y'), (2, 2, 'z'); explain (verbose, costs off) select t1.b, ss.phv from join_ut1 t1 left join lateral (select t2.a as t2a, t3.a t3a, least(t1.a, t2.a, t3.a) phv from join_pt1 t2 join join_ut1 t3 on t2.a = t3.b) ss on t1.a = ss.t2a order by t1.a; QUERY PLAN -------------------------------------------------------------------- Sort Output: t1.b, (LEAST(t1.a, t2.a, t3.a)), t1.a Sort Key: t1.a -> Nested Loop Left Join Output: t1.b, (LEAST(t1.a, t2.a, t3.a)), t1.a -> Seq Scan on public.join_ut1 t1 Output: t1.a, t1.b, t1.c -> Hash Join Output: t2.a, LEAST(t1.a, t2.a, t3.a) Hash Cond: (t3.b = t2.a) -> Seq Scan on public.join_ut1 t3 Output: t3.a, t3.b, t3.c -> Hash Output: t2.a -> Append -> Seq Scan on public.join_pt1p1p1 t2_1 Output: t2_1.a Filter: (t1.a = t2_1.a) -> Seq Scan on public.join_pt1p2 t2_2 Output: t2_2.a Filter: (t1.a = t2_2.a) (21 rows) select t1.b, ss.phv from join_ut1 t1 left join lateral (select t2.a as t2a, t3.a t3a, least(t1.a, t2.a, t3.a) phv from join_pt1 t2 join join_ut1 t3 on t2.a = t3.b) ss on t1.a = ss.t2a order by t1.a; b | phv -----+----- 2 | 101 | 101 (2 rows) drop table join_pt1; drop table join_ut1; -- -- test estimation behavior with multi-column foreign key and constant qual -- begin; create table fkest (x integer, x10 integer, x10b integer, x100 integer); insert into fkest select x, x/10, x/10, x/100 from generate_series(1,1000) x; create unique index on fkest(x, x10, x100); analyze fkest; explain (costs off) select * from fkest f1 join fkest f2 on (f1.x = f2.x and f1.x10 = f2.x10b and f1.x100 = f2.x100) join fkest f3 on f1.x = f3.x where f1.x100 = 2; QUERY PLAN ----------------------------------------------------------- Nested Loop -> Hash Join Hash Cond: ((f2.x = f1.x) AND (f2.x10b = f1.x10)) -> Seq Scan on fkest f2 Filter: (x100 = 2) -> Hash -> Seq Scan on fkest f1 Filter: (x100 = 2) -> Index Scan using fkest_x_x10_x100_idx on fkest f3 Index Cond: (x = f1.x) (10 rows) alter table fkest add constraint fk foreign key (x, x10b, x100) references fkest (x, x10, x100); explain (costs off) select * from fkest f1 join fkest f2 on (f1.x = f2.x and f1.x10 = f2.x10b and f1.x100 = f2.x100) join fkest f3 on f1.x = f3.x where f1.x100 = 2; QUERY PLAN ----------------------------------------------------- Hash Join Hash Cond: ((f2.x = f1.x) AND (f2.x10b = f1.x10)) -> Hash Join Hash Cond: (f3.x = f2.x) -> Seq Scan on fkest f3 -> Hash -> Seq Scan on fkest f2 Filter: (x100 = 2) -> Hash -> Seq Scan on fkest f1 Filter: (x100 = 2) (11 rows) rollback; -- -- test that foreign key join estimation performs sanely for outer joins -- begin; create table fkest (a int, b int, c int unique, primary key(a,b)); create table fkest1 (a int, b int, primary key(a,b)); insert into fkest select x/10, x%10, x from generate_series(1,1000) x; insert into fkest1 select x/10, x%10 from generate_series(1,1000) x; alter table fkest1 add constraint fkest1_a_b_fkey foreign key (a,b) references fkest; analyze fkest; analyze fkest1; explain (costs off) select * from fkest f left join fkest1 f1 on f.a = f1.a and f.b = f1.b left join fkest1 f2 on f.a = f2.a and f.b = f2.b left join fkest1 f3 on f.a = f3.a and f.b = f3.b where f.c = 1; QUERY PLAN ------------------------------------------------------------------ Nested Loop Left Join -> Nested Loop Left Join -> Nested Loop Left Join -> Index Scan using fkest_c_key on fkest f Index Cond: (c = 1) -> Index Only Scan using fkest1_pkey on fkest1 f1 Index Cond: ((a = f.a) AND (b = f.b)) -> Index Only Scan using fkest1_pkey on fkest1 f2 Index Cond: ((a = f.a) AND (b = f.b)) -> Index Only Scan using fkest1_pkey on fkest1 f3 Index Cond: ((a = f.a) AND (b = f.b)) (11 rows) rollback; -- -- test planner's ability to mark joins as unique -- create table j1 (id int primary key); create table j2 (id int primary key); create table j3 (id int); insert into j1 values(1),(2),(3); insert into j2 values(1),(2),(3); insert into j3 values(1),(1); analyze j1; analyze j2; analyze j3; -- ensure join is properly marked as unique explain (verbose, costs off) select * from j1 inner join j2 on j1.id = j2.id; QUERY PLAN ----------------------------------- Hash Join Output: j1.id, j2.id Inner Unique: true Hash Cond: (j1.id = j2.id) -> Seq Scan on public.j1 Output: j1.id -> Hash Output: j2.id -> Seq Scan on public.j2 Output: j2.id (10 rows) -- ensure join is not unique when not an equi-join explain (verbose, costs off) select * from j1 inner join j2 on j1.id > j2.id; QUERY PLAN ----------------------------------- Nested Loop Output: j1.id, j2.id Join Filter: (j1.id > j2.id) -> Seq Scan on public.j1 Output: j1.id -> Materialize Output: j2.id -> Seq Scan on public.j2 Output: j2.id (9 rows) -- ensure non-unique rel is not chosen as inner explain (verbose, costs off) select * from j1 inner join j3 on j1.id = j3.id; QUERY PLAN ----------------------------------- Hash Join Output: j1.id, j3.id Inner Unique: true Hash Cond: (j3.id = j1.id) -> Seq Scan on public.j3 Output: j3.id -> Hash Output: j1.id -> Seq Scan on public.j1 Output: j1.id (10 rows) -- ensure left join is marked as unique explain (verbose, costs off) select * from j1 left join j2 on j1.id = j2.id; QUERY PLAN ----------------------------------- Hash Left Join Output: j1.id, j2.id Inner Unique: true Hash Cond: (j1.id = j2.id) -> Seq Scan on public.j1 Output: j1.id -> Hash Output: j2.id -> Seq Scan on public.j2 Output: j2.id (10 rows) -- ensure right join is marked as unique explain (verbose, costs off) select * from j1 right join j2 on j1.id = j2.id; QUERY PLAN ----------------------------------- Hash Left Join Output: j1.id, j2.id Inner Unique: true Hash Cond: (j2.id = j1.id) -> Seq Scan on public.j2 Output: j2.id -> Hash Output: j1.id -> Seq Scan on public.j1 Output: j1.id (10 rows) -- ensure full join is marked as unique explain (verbose, costs off) select * from j1 full join j2 on j1.id = j2.id; QUERY PLAN ----------------------------------- Hash Full Join Output: j1.id, j2.id Inner Unique: true Hash Cond: (j1.id = j2.id) -> Seq Scan on public.j1 Output: j1.id -> Hash Output: j2.id -> Seq Scan on public.j2 Output: j2.id (10 rows) -- a clauseless (cross) join can't be unique explain (verbose, costs off) select * from j1 cross join j2; QUERY PLAN ----------------------------------- Nested Loop Output: j1.id, j2.id -> Seq Scan on public.j1 Output: j1.id -> Materialize Output: j2.id -> Seq Scan on public.j2 Output: j2.id (8 rows) -- ensure a natural join is marked as unique explain (verbose, costs off) select * from j1 natural join j2; QUERY PLAN ----------------------------------- Hash Join Output: j1.id Inner Unique: true Hash Cond: (j1.id = j2.id) -> Seq Scan on public.j1 Output: j1.id -> Hash Output: j2.id -> Seq Scan on public.j2 Output: j2.id (10 rows) -- ensure a distinct clause allows the inner to become unique explain (verbose, costs off) select * from j1 inner join (select distinct id from j3) j3 on j1.id = j3.id; QUERY PLAN ----------------------------------------- Nested Loop Output: j1.id, j3.id Inner Unique: true Join Filter: (j1.id = j3.id) -> Unique Output: j3.id -> Sort Output: j3.id Sort Key: j3.id -> Seq Scan on public.j3 Output: j3.id -> Seq Scan on public.j1 Output: j1.id (13 rows) -- ensure group by clause allows the inner to become unique explain (verbose, costs off) select * from j1 inner join (select id from j3 group by id) j3 on j1.id = j3.id; QUERY PLAN ----------------------------------------- Nested Loop Output: j1.id, j3.id Inner Unique: true Join Filter: (j1.id = j3.id) -> Group Output: j3.id Group Key: j3.id -> Sort Output: j3.id Sort Key: j3.id -> Seq Scan on public.j3 Output: j3.id -> Seq Scan on public.j1 Output: j1.id (14 rows) drop table j1; drop table j2; drop table j3; -- test more complex permutations of unique joins create table j1 (id1 int, id2 int, primary key(id1,id2)); create table j2 (id1 int, id2 int, primary key(id1,id2)); create table j3 (id1 int, id2 int, primary key(id1,id2)); insert into j1 values(1,1),(1,2); insert into j2 values(1,1); insert into j3 values(1,1); analyze j1; analyze j2; analyze j3; -- ensure there's no unique join when not all columns which are part of the -- unique index are seen in the join clause explain (verbose, costs off) select * from j1 inner join j2 on j1.id1 = j2.id1; QUERY PLAN ------------------------------------------ Nested Loop Output: j1.id1, j1.id2, j2.id1, j2.id2 Join Filter: (j1.id1 = j2.id1) -> Seq Scan on public.j2 Output: j2.id1, j2.id2 -> Seq Scan on public.j1 Output: j1.id1, j1.id2 (7 rows) -- ensure proper unique detection with multiple join quals explain (verbose, costs off) select * from j1 inner join j2 on j1.id1 = j2.id1 and j1.id2 = j2.id2; QUERY PLAN ---------------------------------------------------------- Nested Loop Output: j1.id1, j1.id2, j2.id1, j2.id2 Inner Unique: true Join Filter: ((j1.id1 = j2.id1) AND (j1.id2 = j2.id2)) -> Seq Scan on public.j2 Output: j2.id1, j2.id2 -> Seq Scan on public.j1 Output: j1.id1, j1.id2 (8 rows) -- ensure we don't detect the join to be unique when quals are not part of the -- join condition explain (verbose, costs off) select * from j1 inner join j2 on j1.id1 = j2.id1 where j1.id2 = 1; QUERY PLAN ------------------------------------------ Nested Loop Output: j1.id1, j1.id2, j2.id1, j2.id2 Join Filter: (j1.id1 = j2.id1) -> Seq Scan on public.j1 Output: j1.id1, j1.id2 Filter: (j1.id2 = 1) -> Seq Scan on public.j2 Output: j2.id1, j2.id2 (8 rows) -- as above, but for left joins. explain (verbose, costs off) select * from j1 left join j2 on j1.id1 = j2.id1 where j1.id2 = 1; QUERY PLAN ------------------------------------------ Nested Loop Left Join Output: j1.id1, j1.id2, j2.id1, j2.id2 Join Filter: (j1.id1 = j2.id1) -> Seq Scan on public.j1 Output: j1.id1, j1.id2 Filter: (j1.id2 = 1) -> Seq Scan on public.j2 Output: j2.id1, j2.id2 (8 rows) -- validate logic in merge joins which skips mark and restore. -- it should only do this if all quals which were used to detect the unique -- are present as join quals, and not plain quals. set enable_nestloop to 0; set enable_hashjoin to 0; set enable_sort to 0; -- create indexes that will be preferred over the PKs to perform the join create index j1_id1_idx on j1 (id1) where id1 % 1000 = 1; create index j2_id1_idx on j2 (id1) where id1 % 1000 = 1; -- need an additional row in j2, if we want j2_id1_idx to be preferred insert into j2 values(1,2); analyze j2; explain (costs off) select * from j1 inner join j2 on j1.id1 = j2.id1 and j1.id2 = j2.id2 where j1.id1 % 1000 = 1 and j2.id1 % 1000 = 1; QUERY PLAN ----------------------------------------- Merge Join Merge Cond: (j1.id1 = j2.id1) Join Filter: (j2.id2 = j1.id2) -> Index Scan using j1_id1_idx on j1 -> Index Scan using j2_id1_idx on j2 (5 rows) select * from j1 inner join j2 on j1.id1 = j2.id1 and j1.id2 = j2.id2 where j1.id1 % 1000 = 1 and j2.id1 % 1000 = 1; id1 | id2 | id1 | id2 -----+-----+-----+----- 1 | 1 | 1 | 1 1 | 2 | 1 | 2 (2 rows) -- Exercise array keys mark/restore B-Tree code explain (costs off) select * from j1 inner join j2 on j1.id1 = j2.id1 and j1.id2 = j2.id2 where j1.id1 % 1000 = 1 and j2.id1 % 1000 = 1 and j2.id1 = any (array[1]); QUERY PLAN ---------------------------------------------------- Merge Join Merge Cond: (j1.id1 = j2.id1) Join Filter: (j2.id2 = j1.id2) -> Index Scan using j1_id1_idx on j1 -> Index Scan using j2_id1_idx on j2 Index Cond: (id1 = ANY ('{1}'::integer[])) (6 rows) select * from j1 inner join j2 on j1.id1 = j2.id1 and j1.id2 = j2.id2 where j1.id1 % 1000 = 1 and j2.id1 % 1000 = 1 and j2.id1 = any (array[1]); id1 | id2 | id1 | id2 -----+-----+-----+----- 1 | 1 | 1 | 1 1 | 2 | 1 | 2 (2 rows) -- Exercise array keys "find extreme element" B-Tree code explain (costs off) select * from j1 inner join j2 on j1.id1 = j2.id1 and j1.id2 = j2.id2 where j1.id1 % 1000 = 1 and j2.id1 % 1000 = 1 and j2.id1 >= any (array[1,5]); QUERY PLAN ------------------------------------------------------- Merge Join Merge Cond: (j1.id1 = j2.id1) Join Filter: (j2.id2 = j1.id2) -> Index Scan using j1_id1_idx on j1 -> Index Only Scan using j2_pkey on j2 Index Cond: (id1 >= ANY ('{1,5}'::integer[])) Filter: ((id1 % 1000) = 1) (7 rows) select * from j1 inner join j2 on j1.id1 = j2.id1 and j1.id2 = j2.id2 where j1.id1 % 1000 = 1 and j2.id1 % 1000 = 1 and j2.id1 >= any (array[1,5]); id1 | id2 | id1 | id2 -----+-----+-----+----- 1 | 1 | 1 | 1 1 | 2 | 1 | 2 (2 rows) reset enable_nestloop; reset enable_hashjoin; reset enable_sort; drop table j1; drop table j2; drop table j3; -- check that semijoin inner is not seen as unique for a portion of the outerrel explain (verbose, costs off) select t1.unique1, t2.hundred from onek t1, tenk1 t2 where exists (select 1 from tenk1 t3 where t3.thousand = t1.unique1 and t3.tenthous = t2.hundred) and t1.unique1 < 1; QUERY PLAN --------------------------------------------------------------------------------- Nested Loop Output: t1.unique1, t2.hundred -> Hash Join Output: t1.unique1, t3.tenthous Hash Cond: (t3.thousand = t1.unique1) -> HashAggregate Output: t3.thousand, t3.tenthous Group Key: t3.thousand, t3.tenthous -> Index Only Scan using tenk1_thous_tenthous on public.tenk1 t3 Output: t3.thousand, t3.tenthous -> Hash Output: t1.unique1 -> Index Only Scan using onek_unique1 on public.onek t1 Output: t1.unique1 Index Cond: (t1.unique1 < 1) -> Index Only Scan using tenk1_hundred on public.tenk1 t2 Output: t2.hundred Index Cond: (t2.hundred = t3.tenthous) (18 rows) -- ... unless it actually is unique create table j3 as select unique1, tenthous from onek; vacuum analyze j3; create unique index on j3(unique1, tenthous); explain (verbose, costs off) select t1.unique1, t2.hundred from onek t1, tenk1 t2 where exists (select 1 from j3 where j3.unique1 = t1.unique1 and j3.tenthous = t2.hundred) and t1.unique1 < 1; QUERY PLAN ------------------------------------------------------------------------ Nested Loop Output: t1.unique1, t2.hundred -> Nested Loop Output: t1.unique1, j3.tenthous -> Index Only Scan using onek_unique1 on public.onek t1 Output: t1.unique1 Index Cond: (t1.unique1 < 1) -> Index Only Scan using j3_unique1_tenthous_idx on public.j3 Output: j3.unique1, j3.tenthous Index Cond: (j3.unique1 = t1.unique1) -> Index Only Scan using tenk1_hundred on public.tenk1 t2 Output: t2.hundred Index Cond: (t2.hundred = j3.tenthous) (13 rows) drop table j3;