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Diffstat (limited to 'src/test/regress/expected/with.out')
| -rw-r--r-- | src/test/regress/expected/with.out | 3532 |
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diff --git a/src/test/regress/expected/with.out b/src/test/regress/expected/with.out new file mode 100644 index 0000000..a01efa5 --- /dev/null +++ b/src/test/regress/expected/with.out @@ -0,0 +1,3532 @@ +-- +-- Tests for common table expressions (WITH query, ... SELECT ...) +-- +-- Basic WITH +WITH q1(x,y) AS (SELECT 1,2) +SELECT * FROM q1, q1 AS q2; + x | y | x | y +---+---+---+--- + 1 | 2 | 1 | 2 +(1 row) + +-- Multiple uses are evaluated only once +SELECT count(*) FROM ( + WITH q1(x) AS (SELECT random() FROM generate_series(1, 5)) + SELECT * FROM q1 + UNION + SELECT * FROM q1 +) ss; + count +------- + 5 +(1 row) + +-- WITH RECURSIVE +-- sum of 1..100 +WITH RECURSIVE t(n) AS ( + VALUES (1) +UNION ALL + SELECT n+1 FROM t WHERE n < 100 +) +SELECT sum(n) FROM t; + sum +------ + 5050 +(1 row) + +WITH RECURSIVE t(n) AS ( + SELECT (VALUES(1)) +UNION ALL + SELECT n+1 FROM t WHERE n < 5 +) +SELECT * FROM t; + n +--- + 1 + 2 + 3 + 4 + 5 +(5 rows) + +-- UNION DISTINCT requires hashable type +WITH RECURSIVE t(n) AS ( + VALUES (1::money) +UNION + SELECT n+1::money FROM t WHERE n < 100::money +) +SELECT sum(n) FROM t; +ERROR: could not implement recursive UNION +DETAIL: All column datatypes must be hashable. +-- recursive view +CREATE RECURSIVE VIEW nums (n) AS + VALUES (1) +UNION ALL + SELECT n+1 FROM nums WHERE n < 5; +SELECT * FROM nums; + n +--- + 1 + 2 + 3 + 4 + 5 +(5 rows) + +CREATE OR REPLACE RECURSIVE VIEW nums (n) AS + VALUES (1) +UNION ALL + SELECT n+1 FROM nums WHERE n < 6; +SELECT * FROM nums; + n +--- + 1 + 2 + 3 + 4 + 5 + 6 +(6 rows) + +-- This is an infinite loop with UNION ALL, but not with UNION +WITH RECURSIVE t(n) AS ( + SELECT 1 +UNION + SELECT 10-n FROM t) +SELECT * FROM t; + n +--- + 1 + 9 +(2 rows) + +-- This'd be an infinite loop, but outside query reads only as much as needed +WITH RECURSIVE t(n) AS ( + VALUES (1) +UNION ALL + SELECT n+1 FROM t) +SELECT * FROM t LIMIT 10; + n +---- + 1 + 2 + 3 + 4 + 5 + 6 + 7 + 8 + 9 + 10 +(10 rows) + +-- UNION case should have same property +WITH RECURSIVE t(n) AS ( + SELECT 1 +UNION + SELECT n+1 FROM t) +SELECT * FROM t LIMIT 10; + n +---- + 1 + 2 + 3 + 4 + 5 + 6 + 7 + 8 + 9 + 10 +(10 rows) + +-- Test behavior with an unknown-type literal in the WITH +WITH q AS (SELECT 'foo' AS x) +SELECT x, pg_typeof(x) FROM q; + x | pg_typeof +-----+----------- + foo | text +(1 row) + +WITH RECURSIVE t(n) AS ( + SELECT 'foo' +UNION ALL + SELECT n || ' bar' FROM t WHERE length(n) < 20 +) +SELECT n, pg_typeof(n) FROM t; + n | pg_typeof +-------------------------+----------- + foo | text + foo bar | text + foo bar bar | text + foo bar bar bar | text + foo bar bar bar bar | text + foo bar bar bar bar bar | text +(6 rows) + +-- In a perfect world, this would work and resolve the literal as int ... +-- but for now, we have to be content with resolving to text too soon. +WITH RECURSIVE t(n) AS ( + SELECT '7' +UNION ALL + SELECT n+1 FROM t WHERE n < 10 +) +SELECT n, pg_typeof(n) FROM t; +ERROR: operator does not exist: text + integer +LINE 4: SELECT n+1 FROM t WHERE n < 10 + ^ +HINT: No operator matches the given name and argument types. You might need to add explicit type casts. +-- Deeply nested WITH caused a list-munging problem in v13 +-- Detection of cross-references and self-references +WITH RECURSIVE w1(c1) AS + (WITH w2(c2) AS + (WITH w3(c3) AS + (WITH w4(c4) AS + (WITH w5(c5) AS + (WITH RECURSIVE w6(c6) AS + (WITH w6(c6) AS + (WITH w8(c8) AS + (SELECT 1) + SELECT * FROM w8) + SELECT * FROM w6) + SELECT * FROM w6) + SELECT * FROM w5) + SELECT * FROM w4) + SELECT * FROM w3) + SELECT * FROM w2) +SELECT * FROM w1; + c1 +---- + 1 +(1 row) + +-- Detection of invalid self-references +WITH RECURSIVE outermost(x) AS ( + SELECT 1 + UNION (WITH innermost1 AS ( + SELECT 2 + UNION (WITH innermost2 AS ( + SELECT 3 + UNION (WITH innermost3 AS ( + SELECT 4 + UNION (WITH innermost4 AS ( + SELECT 5 + UNION (WITH innermost5 AS ( + SELECT 6 + UNION (WITH innermost6 AS + (SELECT 7) + SELECT * FROM innermost6)) + SELECT * FROM innermost5)) + SELECT * FROM innermost4)) + SELECT * FROM innermost3)) + SELECT * FROM innermost2)) + SELECT * FROM outermost + UNION SELECT * FROM innermost1) + ) + SELECT * FROM outermost ORDER BY 1; + x +--- + 1 + 2 + 3 + 4 + 5 + 6 + 7 +(7 rows) + +-- +-- Some examples with a tree +-- +-- department structure represented here is as follows: +-- +-- ROOT-+->A-+->B-+->C +-- | | +-- | +->D-+->F +-- +->E-+->G +CREATE TEMP TABLE department ( + id INTEGER PRIMARY KEY, -- department ID + parent_department INTEGER REFERENCES department, -- upper department ID + name TEXT -- department name +); +INSERT INTO department VALUES (0, NULL, 'ROOT'); +INSERT INTO department VALUES (1, 0, 'A'); +INSERT INTO department VALUES (2, 1, 'B'); +INSERT INTO department VALUES (3, 2, 'C'); +INSERT INTO department VALUES (4, 2, 'D'); +INSERT INTO department VALUES (5, 0, 'E'); +INSERT INTO department VALUES (6, 4, 'F'); +INSERT INTO department VALUES (7, 5, 'G'); +-- extract all departments under 'A'. Result should be A, B, C, D and F +WITH RECURSIVE subdepartment AS +( + -- non recursive term + SELECT name as root_name, * FROM department WHERE name = 'A' + UNION ALL + -- recursive term + SELECT sd.root_name, d.* FROM department AS d, subdepartment AS sd + WHERE d.parent_department = sd.id +) +SELECT * FROM subdepartment ORDER BY name; + root_name | id | parent_department | name +-----------+----+-------------------+------ + A | 1 | 0 | A + A | 2 | 1 | B + A | 3 | 2 | C + A | 4 | 2 | D + A | 6 | 4 | F +(5 rows) + +-- extract all departments under 'A' with "level" number +WITH RECURSIVE subdepartment(level, id, parent_department, name) AS +( + -- non recursive term + SELECT 1, * FROM department WHERE name = 'A' + UNION ALL + -- recursive term + SELECT sd.level + 1, d.* FROM department AS d, subdepartment AS sd + WHERE d.parent_department = sd.id +) +SELECT * FROM subdepartment ORDER BY name; + level | id | parent_department | name +-------+----+-------------------+------ + 1 | 1 | 0 | A + 2 | 2 | 1 | B + 3 | 3 | 2 | C + 3 | 4 | 2 | D + 4 | 6 | 4 | F +(5 rows) + +-- extract all departments under 'A' with "level" number. +-- Only shows level 2 or more +WITH RECURSIVE subdepartment(level, id, parent_department, name) AS +( + -- non recursive term + SELECT 1, * FROM department WHERE name = 'A' + UNION ALL + -- recursive term + SELECT sd.level + 1, d.* FROM department AS d, subdepartment AS sd + WHERE d.parent_department = sd.id +) +SELECT * FROM subdepartment WHERE level >= 2 ORDER BY name; + level | id | parent_department | name +-------+----+-------------------+------ + 2 | 2 | 1 | B + 3 | 3 | 2 | C + 3 | 4 | 2 | D + 4 | 6 | 4 | F +(4 rows) + +-- "RECURSIVE" is ignored if the query has no self-reference +WITH RECURSIVE subdepartment AS +( + -- note lack of recursive UNION structure + SELECT * FROM department WHERE name = 'A' +) +SELECT * FROM subdepartment ORDER BY name; + id | parent_department | name +----+-------------------+------ + 1 | 0 | A +(1 row) + +-- inside subqueries +SELECT count(*) FROM ( + WITH RECURSIVE t(n) AS ( + SELECT 1 UNION ALL SELECT n + 1 FROM t WHERE n < 500 + ) + SELECT * FROM t) AS t WHERE n < ( + SELECT count(*) FROM ( + WITH RECURSIVE t(n) AS ( + SELECT 1 UNION ALL SELECT n + 1 FROM t WHERE n < 100 + ) + SELECT * FROM t WHERE n < 50000 + ) AS t WHERE n < 100); + count +------- + 98 +(1 row) + +-- use same CTE twice at different subquery levels +WITH q1(x,y) AS ( + SELECT hundred, sum(ten) FROM tenk1 GROUP BY hundred + ) +SELECT count(*) FROM q1 WHERE y > (SELECT sum(y)/100 FROM q1 qsub); + count +------- + 50 +(1 row) + +-- via a VIEW +CREATE TEMPORARY VIEW vsubdepartment AS + WITH RECURSIVE subdepartment AS + ( + -- non recursive term + SELECT * FROM department WHERE name = 'A' + UNION ALL + -- recursive term + SELECT d.* FROM department AS d, subdepartment AS sd + WHERE d.parent_department = sd.id + ) + SELECT * FROM subdepartment; +SELECT * FROM vsubdepartment ORDER BY name; + id | parent_department | name +----+-------------------+------ + 1 | 0 | A + 2 | 1 | B + 3 | 2 | C + 4 | 2 | D + 6 | 4 | F +(5 rows) + +-- Check reverse listing +SELECT pg_get_viewdef('vsubdepartment'::regclass); + pg_get_viewdef +----------------------------------------------- + WITH RECURSIVE subdepartment AS ( + + SELECT department.id, + + department.parent_department, + + department.name + + FROM department + + WHERE (department.name = 'A'::text)+ + UNION ALL + + SELECT d.id, + + d.parent_department, + + d.name + + FROM department d, + + subdepartment sd + + WHERE (d.parent_department = sd.id)+ + ) + + SELECT id, + + parent_department, + + name + + FROM subdepartment; +(1 row) + +SELECT pg_get_viewdef('vsubdepartment'::regclass, true); + pg_get_viewdef +--------------------------------------------- + WITH RECURSIVE subdepartment AS ( + + SELECT department.id, + + department.parent_department, + + department.name + + FROM department + + WHERE department.name = 'A'::text+ + UNION ALL + + SELECT d.id, + + d.parent_department, + + d.name + + FROM department d, + + subdepartment sd + + WHERE d.parent_department = sd.id+ + ) + + SELECT id, + + parent_department, + + name + + FROM subdepartment; +(1 row) + +-- Another reverse-listing example +CREATE VIEW sums_1_100 AS +WITH RECURSIVE t(n) AS ( + VALUES (1) +UNION ALL + SELECT n+1 FROM t WHERE n < 100 +) +SELECT sum(n) FROM t; +\d+ sums_1_100 + View "public.sums_1_100" + Column | Type | Collation | Nullable | Default | Storage | Description +--------+--------+-----------+----------+---------+---------+------------- + sum | bigint | | | | plain | +View definition: + WITH RECURSIVE t(n) AS ( + VALUES (1) + UNION ALL + SELECT t_1.n + 1 + FROM t t_1 + WHERE t_1.n < 100 + ) + SELECT sum(n) AS sum + FROM t; + +-- corner case in which sub-WITH gets initialized first +with recursive q as ( + select * from department + union all + (with x as (select * from q) + select * from x) + ) +select * from q limit 24; + id | parent_department | name +----+-------------------+------ + 0 | | ROOT + 1 | 0 | A + 2 | 1 | B + 3 | 2 | C + 4 | 2 | D + 5 | 0 | E + 6 | 4 | F + 7 | 5 | G + 0 | | ROOT + 1 | 0 | A + 2 | 1 | B + 3 | 2 | C + 4 | 2 | D + 5 | 0 | E + 6 | 4 | F + 7 | 5 | G + 0 | | ROOT + 1 | 0 | A + 2 | 1 | B + 3 | 2 | C + 4 | 2 | D + 5 | 0 | E + 6 | 4 | F + 7 | 5 | G +(24 rows) + +with recursive q as ( + select * from department + union all + (with recursive x as ( + select * from department + union all + (select * from q union all select * from x) + ) + select * from x) + ) +select * from q limit 32; + id | parent_department | name +----+-------------------+------ + 0 | | ROOT + 1 | 0 | A + 2 | 1 | B + 3 | 2 | C + 4 | 2 | D + 5 | 0 | E + 6 | 4 | F + 7 | 5 | G + 0 | | ROOT + 1 | 0 | A + 2 | 1 | B + 3 | 2 | C + 4 | 2 | D + 5 | 0 | E + 6 | 4 | F + 7 | 5 | G + 0 | | ROOT + 1 | 0 | A + 2 | 1 | B + 3 | 2 | C + 4 | 2 | D + 5 | 0 | E + 6 | 4 | F + 7 | 5 | G + 0 | | ROOT + 1 | 0 | A + 2 | 1 | B + 3 | 2 | C + 4 | 2 | D + 5 | 0 | E + 6 | 4 | F + 7 | 5 | G +(32 rows) + +-- recursive term has sub-UNION +WITH RECURSIVE t(i,j) AS ( + VALUES (1,2) + UNION ALL + SELECT t2.i, t.j+1 FROM + (SELECT 2 AS i UNION ALL SELECT 3 AS i) AS t2 + JOIN t ON (t2.i = t.i+1)) + SELECT * FROM t; + i | j +---+--- + 1 | 2 + 2 | 3 + 3 | 4 +(3 rows) + +-- +-- different tree example +-- +CREATE TEMPORARY TABLE tree( + id INTEGER PRIMARY KEY, + parent_id INTEGER REFERENCES tree(id) +); +INSERT INTO tree +VALUES (1, NULL), (2, 1), (3,1), (4,2), (5,2), (6,2), (7,3), (8,3), + (9,4), (10,4), (11,7), (12,7), (13,7), (14, 9), (15,11), (16,11); +-- +-- get all paths from "second level" nodes to leaf nodes +-- +WITH RECURSIVE t(id, path) AS ( + VALUES(1,ARRAY[]::integer[]) +UNION ALL + SELECT tree.id, t.path || tree.id + FROM tree JOIN t ON (tree.parent_id = t.id) +) +SELECT t1.*, t2.* FROM t AS t1 JOIN t AS t2 ON + (t1.path[1] = t2.path[1] AND + array_upper(t1.path,1) = 1 AND + array_upper(t2.path,1) > 1) + ORDER BY t1.id, t2.id; + id | path | id | path +----+------+----+------------- + 2 | {2} | 4 | {2,4} + 2 | {2} | 5 | {2,5} + 2 | {2} | 6 | {2,6} + 2 | {2} | 9 | {2,4,9} + 2 | {2} | 10 | {2,4,10} + 2 | {2} | 14 | {2,4,9,14} + 3 | {3} | 7 | {3,7} + 3 | {3} | 8 | {3,8} + 3 | {3} | 11 | {3,7,11} + 3 | {3} | 12 | {3,7,12} + 3 | {3} | 13 | {3,7,13} + 3 | {3} | 15 | {3,7,11,15} + 3 | {3} | 16 | {3,7,11,16} +(13 rows) + +-- just count 'em +WITH RECURSIVE t(id, path) AS ( + VALUES(1,ARRAY[]::integer[]) +UNION ALL + SELECT tree.id, t.path || tree.id + FROM tree JOIN t ON (tree.parent_id = t.id) +) +SELECT t1.id, count(t2.*) FROM t AS t1 JOIN t AS t2 ON + (t1.path[1] = t2.path[1] AND + array_upper(t1.path,1) = 1 AND + array_upper(t2.path,1) > 1) + GROUP BY t1.id + ORDER BY t1.id; + id | count +----+------- + 2 | 6 + 3 | 7 +(2 rows) + +-- this variant tickled a whole-row-variable bug in 8.4devel +WITH RECURSIVE t(id, path) AS ( + VALUES(1,ARRAY[]::integer[]) +UNION ALL + SELECT tree.id, t.path || tree.id + FROM tree JOIN t ON (tree.parent_id = t.id) +) +SELECT t1.id, t2.path, t2 FROM t AS t1 JOIN t AS t2 ON +(t1.id=t2.id); + id | path | t2 +----+-------------+-------------------- + 1 | {} | (1,{}) + 2 | {2} | (2,{2}) + 3 | {3} | (3,{3}) + 4 | {2,4} | (4,"{2,4}") + 5 | {2,5} | (5,"{2,5}") + 6 | {2,6} | (6,"{2,6}") + 7 | {3,7} | (7,"{3,7}") + 8 | {3,8} | (8,"{3,8}") + 9 | {2,4,9} | (9,"{2,4,9}") + 10 | {2,4,10} | (10,"{2,4,10}") + 11 | {3,7,11} | (11,"{3,7,11}") + 12 | {3,7,12} | (12,"{3,7,12}") + 13 | {3,7,13} | (13,"{3,7,13}") + 14 | {2,4,9,14} | (14,"{2,4,9,14}") + 15 | {3,7,11,15} | (15,"{3,7,11,15}") + 16 | {3,7,11,16} | (16,"{3,7,11,16}") +(16 rows) + +-- SEARCH clause +create temp table graph0( f int, t int, label text ); +insert into graph0 values + (1, 2, 'arc 1 -> 2'), + (1, 3, 'arc 1 -> 3'), + (2, 3, 'arc 2 -> 3'), + (1, 4, 'arc 1 -> 4'), + (4, 5, 'arc 4 -> 5'); +explain (verbose, costs off) +with recursive search_graph(f, t, label) as ( + select * from graph0 g + union all + select g.* + from graph0 g, search_graph sg + where g.f = sg.t +) search depth first by f, t set seq +select * from search_graph order by seq; + QUERY PLAN +---------------------------------------------------------------------------------------------- + Sort + Output: search_graph.f, search_graph.t, search_graph.label, search_graph.seq + Sort Key: search_graph.seq + CTE search_graph + -> Recursive Union + -> Seq Scan on pg_temp.graph0 g + Output: g.f, g.t, g.label, ARRAY[ROW(g.f, g.t)] + -> Merge Join + Output: g_1.f, g_1.t, g_1.label, array_cat(sg.seq, ARRAY[ROW(g_1.f, g_1.t)]) + Merge Cond: (g_1.f = sg.t) + -> Sort + Output: g_1.f, g_1.t, g_1.label + Sort Key: g_1.f + -> Seq Scan on pg_temp.graph0 g_1 + Output: g_1.f, g_1.t, g_1.label + -> Sort + Output: sg.seq, sg.t + Sort Key: sg.t + -> WorkTable Scan on search_graph sg + Output: sg.seq, sg.t + -> CTE Scan on search_graph + Output: search_graph.f, search_graph.t, search_graph.label, search_graph.seq +(22 rows) + +with recursive search_graph(f, t, label) as ( + select * from graph0 g + union all + select g.* + from graph0 g, search_graph sg + where g.f = sg.t +) search depth first by f, t set seq +select * from search_graph order by seq; + f | t | label | seq +---+---+------------+------------------- + 1 | 2 | arc 1 -> 2 | {"(1,2)"} + 2 | 3 | arc 2 -> 3 | {"(1,2)","(2,3)"} + 1 | 3 | arc 1 -> 3 | {"(1,3)"} + 1 | 4 | arc 1 -> 4 | {"(1,4)"} + 4 | 5 | arc 4 -> 5 | {"(1,4)","(4,5)"} + 2 | 3 | arc 2 -> 3 | {"(2,3)"} + 4 | 5 | arc 4 -> 5 | {"(4,5)"} +(7 rows) + +with recursive search_graph(f, t, label) as ( + select * from graph0 g + union distinct + select g.* + from graph0 g, search_graph sg + where g.f = sg.t +) search depth first by f, t set seq +select * from search_graph order by seq; + f | t | label | seq +---+---+------------+------------------- + 1 | 2 | arc 1 -> 2 | {"(1,2)"} + 2 | 3 | arc 2 -> 3 | {"(1,2)","(2,3)"} + 1 | 3 | arc 1 -> 3 | {"(1,3)"} + 1 | 4 | arc 1 -> 4 | {"(1,4)"} + 4 | 5 | arc 4 -> 5 | {"(1,4)","(4,5)"} + 2 | 3 | arc 2 -> 3 | {"(2,3)"} + 4 | 5 | arc 4 -> 5 | {"(4,5)"} +(7 rows) + +explain (verbose, costs off) +with recursive search_graph(f, t, label) as ( + select * from graph0 g + union all + select g.* + from graph0 g, search_graph sg + where g.f = sg.t +) search breadth first by f, t set seq +select * from search_graph order by seq; + QUERY PLAN +------------------------------------------------------------------------------------------------- + Sort + Output: search_graph.f, search_graph.t, search_graph.label, search_graph.seq + Sort Key: search_graph.seq + CTE search_graph + -> Recursive Union + -> Seq Scan on pg_temp.graph0 g + Output: g.f, g.t, g.label, ROW('0'::bigint, g.f, g.t) + -> Merge Join + Output: g_1.f, g_1.t, g_1.label, ROW(int8inc((sg.seq)."*DEPTH*"), g_1.f, g_1.t) + Merge Cond: (g_1.f = sg.t) + -> Sort + Output: g_1.f, g_1.t, g_1.label + Sort Key: g_1.f + -> Seq Scan on pg_temp.graph0 g_1 + Output: g_1.f, g_1.t, g_1.label + -> Sort + Output: sg.seq, sg.t + Sort Key: sg.t + -> WorkTable Scan on search_graph sg + Output: sg.seq, sg.t + -> CTE Scan on search_graph + Output: search_graph.f, search_graph.t, search_graph.label, search_graph.seq +(22 rows) + +with recursive search_graph(f, t, label) as ( + select * from graph0 g + union all + select g.* + from graph0 g, search_graph sg + where g.f = sg.t +) search breadth first by f, t set seq +select * from search_graph order by seq; + f | t | label | seq +---+---+------------+--------- + 1 | 2 | arc 1 -> 2 | (0,1,2) + 1 | 3 | arc 1 -> 3 | (0,1,3) + 1 | 4 | arc 1 -> 4 | (0,1,4) + 2 | 3 | arc 2 -> 3 | (0,2,3) + 4 | 5 | arc 4 -> 5 | (0,4,5) + 2 | 3 | arc 2 -> 3 | (1,2,3) + 4 | 5 | arc 4 -> 5 | (1,4,5) +(7 rows) + +with recursive search_graph(f, t, label) as ( + select * from graph0 g + union distinct + select g.* + from graph0 g, search_graph sg + where g.f = sg.t +) search breadth first by f, t set seq +select * from search_graph order by seq; + f | t | label | seq +---+---+------------+--------- + 1 | 2 | arc 1 -> 2 | (0,1,2) + 1 | 3 | arc 1 -> 3 | (0,1,3) + 1 | 4 | arc 1 -> 4 | (0,1,4) + 2 | 3 | arc 2 -> 3 | (0,2,3) + 4 | 5 | arc 4 -> 5 | (0,4,5) + 2 | 3 | arc 2 -> 3 | (1,2,3) + 4 | 5 | arc 4 -> 5 | (1,4,5) +(7 rows) + +-- a constant initial value causes issues for EXPLAIN +explain (verbose, costs off) +with recursive test as ( + select 1 as x + union all + select x + 1 + from test +) search depth first by x set y +select * from test limit 5; + QUERY PLAN +----------------------------------------------------------------------------------------- + Limit + Output: test.x, test.y + CTE test + -> Recursive Union + -> Result + Output: 1, '{(1)}'::record[] + -> WorkTable Scan on test test_1 + Output: (test_1.x + 1), array_cat(test_1.y, ARRAY[ROW((test_1.x + 1))]) + -> CTE Scan on test + Output: test.x, test.y +(10 rows) + +with recursive test as ( + select 1 as x + union all + select x + 1 + from test +) search depth first by x set y +select * from test limit 5; + x | y +---+----------------------- + 1 | {(1)} + 2 | {(1),(2)} + 3 | {(1),(2),(3)} + 4 | {(1),(2),(3),(4)} + 5 | {(1),(2),(3),(4),(5)} +(5 rows) + +explain (verbose, costs off) +with recursive test as ( + select 1 as x + union all + select x + 1 + from test +) search breadth first by x set y +select * from test limit 5; + QUERY PLAN +-------------------------------------------------------------------------------------------- + Limit + Output: test.x, test.y + CTE test + -> Recursive Union + -> Result + Output: 1, '(0,1)'::record + -> WorkTable Scan on test test_1 + Output: (test_1.x + 1), ROW(int8inc((test_1.y)."*DEPTH*"), (test_1.x + 1)) + -> CTE Scan on test + Output: test.x, test.y +(10 rows) + +with recursive test as ( + select 1 as x + union all + select x + 1 + from test +) search breadth first by x set y +select * from test limit 5; + x | y +---+------- + 1 | (0,1) + 2 | (1,2) + 3 | (2,3) + 4 | (3,4) + 5 | (4,5) +(5 rows) + +-- various syntax errors +with recursive search_graph(f, t, label) as ( + select * from graph0 g + union all + select g.* + from graph0 g, search_graph sg + where g.f = sg.t +) search depth first by foo, tar set seq +select * from search_graph; +ERROR: search column "foo" not in WITH query column list +LINE 7: ) search depth first by foo, tar set seq + ^ +with recursive search_graph(f, t, label) as ( + select * from graph0 g + union all + select g.* + from graph0 g, search_graph sg + where g.f = sg.t +) search depth first by f, t set label +select * from search_graph; +ERROR: search sequence column name "label" already used in WITH query column list +LINE 7: ) search depth first by f, t set label + ^ +with recursive search_graph(f, t, label) as ( + select * from graph0 g + union all + select g.* + from graph0 g, search_graph sg + where g.f = sg.t +) search depth first by f, t, f set seq +select * from search_graph; +ERROR: search column "f" specified more than once +LINE 7: ) search depth first by f, t, f set seq + ^ +with recursive search_graph(f, t, label) as ( + select * from graph0 g + union all + select * from graph0 g + union all + select g.* + from graph0 g, search_graph sg + where g.f = sg.t +) search depth first by f, t set seq +select * from search_graph order by seq; +ERROR: with a SEARCH or CYCLE clause, the left side of the UNION must be a SELECT +with recursive search_graph(f, t, label) as ( + select * from graph0 g + union all + (select * from graph0 g + union all + select g.* + from graph0 g, search_graph sg + where g.f = sg.t) +) search depth first by f, t set seq +select * from search_graph order by seq; +ERROR: with a SEARCH or CYCLE clause, the right side of the UNION must be a SELECT +-- check that we distinguish same CTE name used at different levels +-- (this case could be supported, perhaps, but it isn't today) +with recursive x(col) as ( + select 1 + union + (with x as (select * from x) + select * from x) +) search depth first by col set seq +select * from x; +ERROR: with a SEARCH or CYCLE clause, the recursive reference to WITH query "x" must be at the top level of its right-hand SELECT +-- test ruleutils and view expansion +create temp view v_search as +with recursive search_graph(f, t, label) as ( + select * from graph0 g + union all + select g.* + from graph0 g, search_graph sg + where g.f = sg.t +) search depth first by f, t set seq +select f, t, label from search_graph; +select pg_get_viewdef('v_search'); + pg_get_viewdef +------------------------------------------------ + WITH RECURSIVE search_graph(f, t, label) AS (+ + SELECT g.f, + + g.t, + + g.label + + FROM graph0 g + + UNION ALL + + SELECT g.f, + + g.t, + + g.label + + FROM graph0 g, + + search_graph sg + + WHERE (g.f = sg.t) + + ) SEARCH DEPTH FIRST BY f, t SET seq + + SELECT f, + + t, + + label + + FROM search_graph; +(1 row) + +select * from v_search; + f | t | label +---+---+------------ + 1 | 2 | arc 1 -> 2 + 1 | 3 | arc 1 -> 3 + 2 | 3 | arc 2 -> 3 + 1 | 4 | arc 1 -> 4 + 4 | 5 | arc 4 -> 5 + 2 | 3 | arc 2 -> 3 + 4 | 5 | arc 4 -> 5 +(7 rows) + +-- +-- test cycle detection +-- +create temp table graph( f int, t int, label text ); +insert into graph values + (1, 2, 'arc 1 -> 2'), + (1, 3, 'arc 1 -> 3'), + (2, 3, 'arc 2 -> 3'), + (1, 4, 'arc 1 -> 4'), + (4, 5, 'arc 4 -> 5'), + (5, 1, 'arc 5 -> 1'); +with recursive search_graph(f, t, label, is_cycle, path) as ( + select *, false, array[row(g.f, g.t)] from graph g + union all + select g.*, row(g.f, g.t) = any(path), path || row(g.f, g.t) + from graph g, search_graph sg + where g.f = sg.t and not is_cycle +) +select * from search_graph; + f | t | label | is_cycle | path +---+---+------------+----------+------------------------------------------- + 1 | 2 | arc 1 -> 2 | f | {"(1,2)"} + 1 | 3 | arc 1 -> 3 | f | {"(1,3)"} + 2 | 3 | arc 2 -> 3 | f | {"(2,3)"} + 1 | 4 | arc 1 -> 4 | f | {"(1,4)"} + 4 | 5 | arc 4 -> 5 | f | {"(4,5)"} + 5 | 1 | arc 5 -> 1 | f | {"(5,1)"} + 1 | 2 | arc 1 -> 2 | f | {"(5,1)","(1,2)"} + 1 | 3 | arc 1 -> 3 | f | {"(5,1)","(1,3)"} + 1 | 4 | arc 1 -> 4 | f | {"(5,1)","(1,4)"} + 2 | 3 | arc 2 -> 3 | f | {"(1,2)","(2,3)"} + 4 | 5 | arc 4 -> 5 | f | {"(1,4)","(4,5)"} + 5 | 1 | arc 5 -> 1 | f | {"(4,5)","(5,1)"} + 1 | 2 | arc 1 -> 2 | f | {"(4,5)","(5,1)","(1,2)"} + 1 | 3 | arc 1 -> 3 | f | {"(4,5)","(5,1)","(1,3)"} + 1 | 4 | arc 1 -> 4 | f | {"(4,5)","(5,1)","(1,4)"} + 2 | 3 | arc 2 -> 3 | f | {"(5,1)","(1,2)","(2,3)"} + 4 | 5 | arc 4 -> 5 | f | {"(5,1)","(1,4)","(4,5)"} + 5 | 1 | arc 5 -> 1 | f | {"(1,4)","(4,5)","(5,1)"} + 1 | 2 | arc 1 -> 2 | f | {"(1,4)","(4,5)","(5,1)","(1,2)"} + 1 | 3 | arc 1 -> 3 | f | {"(1,4)","(4,5)","(5,1)","(1,3)"} + 1 | 4 | arc 1 -> 4 | t | {"(1,4)","(4,5)","(5,1)","(1,4)"} + 2 | 3 | arc 2 -> 3 | f | {"(4,5)","(5,1)","(1,2)","(2,3)"} + 4 | 5 | arc 4 -> 5 | t | {"(4,5)","(5,1)","(1,4)","(4,5)"} + 5 | 1 | arc 5 -> 1 | t | {"(5,1)","(1,4)","(4,5)","(5,1)"} + 2 | 3 | arc 2 -> 3 | f | {"(1,4)","(4,5)","(5,1)","(1,2)","(2,3)"} +(25 rows) + +-- UNION DISTINCT exercises row type hashing support +with recursive search_graph(f, t, label, is_cycle, path) as ( + select *, false, array[row(g.f, g.t)] from graph g + union distinct + select g.*, row(g.f, g.t) = any(path), path || row(g.f, g.t) + from graph g, search_graph sg + where g.f = sg.t and not is_cycle +) +select * from search_graph; + f | t | label | is_cycle | path +---+---+------------+----------+------------------------------------------- + 1 | 2 | arc 1 -> 2 | f | {"(1,2)"} + 1 | 3 | arc 1 -> 3 | f | {"(1,3)"} + 2 | 3 | arc 2 -> 3 | f | {"(2,3)"} + 1 | 4 | arc 1 -> 4 | f | {"(1,4)"} + 4 | 5 | arc 4 -> 5 | f | {"(4,5)"} + 5 | 1 | arc 5 -> 1 | f | {"(5,1)"} + 1 | 2 | arc 1 -> 2 | f | {"(5,1)","(1,2)"} + 1 | 3 | arc 1 -> 3 | f | {"(5,1)","(1,3)"} + 1 | 4 | arc 1 -> 4 | f | {"(5,1)","(1,4)"} + 2 | 3 | arc 2 -> 3 | f | {"(1,2)","(2,3)"} + 4 | 5 | arc 4 -> 5 | f | {"(1,4)","(4,5)"} + 5 | 1 | arc 5 -> 1 | f | {"(4,5)","(5,1)"} + 1 | 2 | arc 1 -> 2 | f | {"(4,5)","(5,1)","(1,2)"} + 1 | 3 | arc 1 -> 3 | f | {"(4,5)","(5,1)","(1,3)"} + 1 | 4 | arc 1 -> 4 | f | {"(4,5)","(5,1)","(1,4)"} + 2 | 3 | arc 2 -> 3 | f | {"(5,1)","(1,2)","(2,3)"} + 4 | 5 | arc 4 -> 5 | f | {"(5,1)","(1,4)","(4,5)"} + 5 | 1 | arc 5 -> 1 | f | {"(1,4)","(4,5)","(5,1)"} + 1 | 2 | arc 1 -> 2 | f | {"(1,4)","(4,5)","(5,1)","(1,2)"} + 1 | 3 | arc 1 -> 3 | f | {"(1,4)","(4,5)","(5,1)","(1,3)"} + 1 | 4 | arc 1 -> 4 | t | {"(1,4)","(4,5)","(5,1)","(1,4)"} + 2 | 3 | arc 2 -> 3 | f | {"(4,5)","(5,1)","(1,2)","(2,3)"} + 4 | 5 | arc 4 -> 5 | t | {"(4,5)","(5,1)","(1,4)","(4,5)"} + 5 | 1 | arc 5 -> 1 | t | {"(5,1)","(1,4)","(4,5)","(5,1)"} + 2 | 3 | arc 2 -> 3 | f | {"(1,4)","(4,5)","(5,1)","(1,2)","(2,3)"} +(25 rows) + +-- ordering by the path column has same effect as SEARCH DEPTH FIRST +with recursive search_graph(f, t, label, is_cycle, path) as ( + select *, false, array[row(g.f, g.t)] from graph g + union all + select g.*, row(g.f, g.t) = any(path), path || row(g.f, g.t) + from graph g, search_graph sg + where g.f = sg.t and not is_cycle +) +select * from search_graph order by path; + f | t | label | is_cycle | path +---+---+------------+----------+------------------------------------------- + 1 | 2 | arc 1 -> 2 | f | {"(1,2)"} + 2 | 3 | arc 2 -> 3 | f | {"(1,2)","(2,3)"} + 1 | 3 | arc 1 -> 3 | f | {"(1,3)"} + 1 | 4 | arc 1 -> 4 | f | {"(1,4)"} + 4 | 5 | arc 4 -> 5 | f | {"(1,4)","(4,5)"} + 5 | 1 | arc 5 -> 1 | f | {"(1,4)","(4,5)","(5,1)"} + 1 | 2 | arc 1 -> 2 | f | {"(1,4)","(4,5)","(5,1)","(1,2)"} + 2 | 3 | arc 2 -> 3 | f | {"(1,4)","(4,5)","(5,1)","(1,2)","(2,3)"} + 1 | 3 | arc 1 -> 3 | f | {"(1,4)","(4,5)","(5,1)","(1,3)"} + 1 | 4 | arc 1 -> 4 | t | {"(1,4)","(4,5)","(5,1)","(1,4)"} + 2 | 3 | arc 2 -> 3 | f | {"(2,3)"} + 4 | 5 | arc 4 -> 5 | f | {"(4,5)"} + 5 | 1 | arc 5 -> 1 | f | {"(4,5)","(5,1)"} + 1 | 2 | arc 1 -> 2 | f | {"(4,5)","(5,1)","(1,2)"} + 2 | 3 | arc 2 -> 3 | f | {"(4,5)","(5,1)","(1,2)","(2,3)"} + 1 | 3 | arc 1 -> 3 | f | {"(4,5)","(5,1)","(1,3)"} + 1 | 4 | arc 1 -> 4 | f | {"(4,5)","(5,1)","(1,4)"} + 4 | 5 | arc 4 -> 5 | t | {"(4,5)","(5,1)","(1,4)","(4,5)"} + 5 | 1 | arc 5 -> 1 | f | {"(5,1)"} + 1 | 2 | arc 1 -> 2 | f | {"(5,1)","(1,2)"} + 2 | 3 | arc 2 -> 3 | f | {"(5,1)","(1,2)","(2,3)"} + 1 | 3 | arc 1 -> 3 | f | {"(5,1)","(1,3)"} + 1 | 4 | arc 1 -> 4 | f | {"(5,1)","(1,4)"} + 4 | 5 | arc 4 -> 5 | f | {"(5,1)","(1,4)","(4,5)"} + 5 | 1 | arc 5 -> 1 | t | {"(5,1)","(1,4)","(4,5)","(5,1)"} +(25 rows) + +-- CYCLE clause +explain (verbose, costs off) +with recursive search_graph(f, t, label) as ( + select * from graph g + union all + select g.* + from graph g, search_graph sg + where g.f = sg.t +) cycle f, t set is_cycle using path +select * from search_graph; + QUERY PLAN +----------------------------------------------------------------------------------------------------------------------------------------------------------------------- + CTE Scan on search_graph + Output: search_graph.f, search_graph.t, search_graph.label, search_graph.is_cycle, search_graph.path + CTE search_graph + -> Recursive Union + -> Seq Scan on pg_temp.graph g + Output: g.f, g.t, g.label, false, ARRAY[ROW(g.f, g.t)] + -> Merge Join + Output: g_1.f, g_1.t, g_1.label, CASE WHEN (ROW(g_1.f, g_1.t) = ANY (sg.path)) THEN true ELSE false END, array_cat(sg.path, ARRAY[ROW(g_1.f, g_1.t)]) + Merge Cond: (g_1.f = sg.t) + -> Sort + Output: g_1.f, g_1.t, g_1.label + Sort Key: g_1.f + -> Seq Scan on pg_temp.graph g_1 + Output: g_1.f, g_1.t, g_1.label + -> Sort + Output: sg.path, sg.t + Sort Key: sg.t + -> WorkTable Scan on search_graph sg + Output: sg.path, sg.t + Filter: (NOT sg.is_cycle) +(20 rows) + +with recursive search_graph(f, t, label) as ( + select * from graph g + union all + select g.* + from graph g, search_graph sg + where g.f = sg.t +) cycle f, t set is_cycle using path +select * from search_graph; + f | t | label | is_cycle | path +---+---+------------+----------+------------------------------------------- + 1 | 2 | arc 1 -> 2 | f | {"(1,2)"} + 1 | 3 | arc 1 -> 3 | f | {"(1,3)"} + 2 | 3 | arc 2 -> 3 | f | {"(2,3)"} + 1 | 4 | arc 1 -> 4 | f | {"(1,4)"} + 4 | 5 | arc 4 -> 5 | f | {"(4,5)"} + 5 | 1 | arc 5 -> 1 | f | {"(5,1)"} + 1 | 2 | arc 1 -> 2 | f | {"(5,1)","(1,2)"} + 1 | 3 | arc 1 -> 3 | f | {"(5,1)","(1,3)"} + 1 | 4 | arc 1 -> 4 | f | {"(5,1)","(1,4)"} + 2 | 3 | arc 2 -> 3 | f | {"(1,2)","(2,3)"} + 4 | 5 | arc 4 -> 5 | f | {"(1,4)","(4,5)"} + 5 | 1 | arc 5 -> 1 | f | {"(4,5)","(5,1)"} + 1 | 2 | arc 1 -> 2 | f | {"(4,5)","(5,1)","(1,2)"} + 1 | 3 | arc 1 -> 3 | f | {"(4,5)","(5,1)","(1,3)"} + 1 | 4 | arc 1 -> 4 | f | {"(4,5)","(5,1)","(1,4)"} + 2 | 3 | arc 2 -> 3 | f | {"(5,1)","(1,2)","(2,3)"} + 4 | 5 | arc 4 -> 5 | f | {"(5,1)","(1,4)","(4,5)"} + 5 | 1 | arc 5 -> 1 | f | {"(1,4)","(4,5)","(5,1)"} + 1 | 2 | arc 1 -> 2 | f | {"(1,4)","(4,5)","(5,1)","(1,2)"} + 1 | 3 | arc 1 -> 3 | f | {"(1,4)","(4,5)","(5,1)","(1,3)"} + 1 | 4 | arc 1 -> 4 | t | {"(1,4)","(4,5)","(5,1)","(1,4)"} + 2 | 3 | arc 2 -> 3 | f | {"(4,5)","(5,1)","(1,2)","(2,3)"} + 4 | 5 | arc 4 -> 5 | t | {"(4,5)","(5,1)","(1,4)","(4,5)"} + 5 | 1 | arc 5 -> 1 | t | {"(5,1)","(1,4)","(4,5)","(5,1)"} + 2 | 3 | arc 2 -> 3 | f | {"(1,4)","(4,5)","(5,1)","(1,2)","(2,3)"} +(25 rows) + +with recursive search_graph(f, t, label) as ( + select * from graph g + union distinct + select g.* + from graph g, search_graph sg + where g.f = sg.t +) cycle f, t set is_cycle to 'Y' default 'N' using path +select * from search_graph; + f | t | label | is_cycle | path +---+---+------------+----------+------------------------------------------- + 1 | 2 | arc 1 -> 2 | N | {"(1,2)"} + 1 | 3 | arc 1 -> 3 | N | {"(1,3)"} + 2 | 3 | arc 2 -> 3 | N | {"(2,3)"} + 1 | 4 | arc 1 -> 4 | N | {"(1,4)"} + 4 | 5 | arc 4 -> 5 | N | {"(4,5)"} + 5 | 1 | arc 5 -> 1 | N | {"(5,1)"} + 1 | 2 | arc 1 -> 2 | N | {"(5,1)","(1,2)"} + 1 | 3 | arc 1 -> 3 | N | {"(5,1)","(1,3)"} + 1 | 4 | arc 1 -> 4 | N | {"(5,1)","(1,4)"} + 2 | 3 | arc 2 -> 3 | N | {"(1,2)","(2,3)"} + 4 | 5 | arc 4 -> 5 | N | {"(1,4)","(4,5)"} + 5 | 1 | arc 5 -> 1 | N | {"(4,5)","(5,1)"} + 1 | 2 | arc 1 -> 2 | N | {"(4,5)","(5,1)","(1,2)"} + 1 | 3 | arc 1 -> 3 | N | {"(4,5)","(5,1)","(1,3)"} + 1 | 4 | arc 1 -> 4 | N | {"(4,5)","(5,1)","(1,4)"} + 2 | 3 | arc 2 -> 3 | N | {"(5,1)","(1,2)","(2,3)"} + 4 | 5 | arc 4 -> 5 | N | {"(5,1)","(1,4)","(4,5)"} + 5 | 1 | arc 5 -> 1 | N | {"(1,4)","(4,5)","(5,1)"} + 1 | 2 | arc 1 -> 2 | N | {"(1,4)","(4,5)","(5,1)","(1,2)"} + 1 | 3 | arc 1 -> 3 | N | {"(1,4)","(4,5)","(5,1)","(1,3)"} + 1 | 4 | arc 1 -> 4 | Y | {"(1,4)","(4,5)","(5,1)","(1,4)"} + 2 | 3 | arc 2 -> 3 | N | {"(4,5)","(5,1)","(1,2)","(2,3)"} + 4 | 5 | arc 4 -> 5 | Y | {"(4,5)","(5,1)","(1,4)","(4,5)"} + 5 | 1 | arc 5 -> 1 | Y | {"(5,1)","(1,4)","(4,5)","(5,1)"} + 2 | 3 | arc 2 -> 3 | N | {"(1,4)","(4,5)","(5,1)","(1,2)","(2,3)"} +(25 rows) + +explain (verbose, costs off) +with recursive test as ( + select 0 as x + union all + select (x + 1) % 10 + from test +) cycle x set is_cycle using path +select * from test; + QUERY PLAN +----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- + CTE Scan on test + Output: test.x, test.is_cycle, test.path + CTE test + -> Recursive Union + -> Result + Output: 0, false, '{(0)}'::record[] + -> WorkTable Scan on test test_1 + Output: ((test_1.x + 1) % 10), CASE WHEN (ROW(((test_1.x + 1) % 10)) = ANY (test_1.path)) THEN true ELSE false END, array_cat(test_1.path, ARRAY[ROW(((test_1.x + 1) % 10))]) + Filter: (NOT test_1.is_cycle) +(9 rows) + +with recursive test as ( + select 0 as x + union all + select (x + 1) % 10 + from test +) cycle x set is_cycle using path +select * from test; + x | is_cycle | path +---+----------+----------------------------------------------- + 0 | f | {(0)} + 1 | f | {(0),(1)} + 2 | f | {(0),(1),(2)} + 3 | f | {(0),(1),(2),(3)} + 4 | f | {(0),(1),(2),(3),(4)} + 5 | f | {(0),(1),(2),(3),(4),(5)} + 6 | f | {(0),(1),(2),(3),(4),(5),(6)} + 7 | f | {(0),(1),(2),(3),(4),(5),(6),(7)} + 8 | f | {(0),(1),(2),(3),(4),(5),(6),(7),(8)} + 9 | f | {(0),(1),(2),(3),(4),(5),(6),(7),(8),(9)} + 0 | t | {(0),(1),(2),(3),(4),(5),(6),(7),(8),(9),(0)} +(11 rows) + +with recursive test as ( + select 0 as x + union all + select (x + 1) % 10 + from test + where not is_cycle -- redundant, but legal +) cycle x set is_cycle using path +select * from test; + x | is_cycle | path +---+----------+----------------------------------------------- + 0 | f | {(0)} + 1 | f | {(0),(1)} + 2 | f | {(0),(1),(2)} + 3 | f | {(0),(1),(2),(3)} + 4 | f | {(0),(1),(2),(3),(4)} + 5 | f | {(0),(1),(2),(3),(4),(5)} + 6 | f | {(0),(1),(2),(3),(4),(5),(6)} + 7 | f | {(0),(1),(2),(3),(4),(5),(6),(7)} + 8 | f | {(0),(1),(2),(3),(4),(5),(6),(7),(8)} + 9 | f | {(0),(1),(2),(3),(4),(5),(6),(7),(8),(9)} + 0 | t | {(0),(1),(2),(3),(4),(5),(6),(7),(8),(9),(0)} +(11 rows) + +-- multiple CTEs +with recursive +graph(f, t, label) as ( + values (1, 2, 'arc 1 -> 2'), + (1, 3, 'arc 1 -> 3'), + (2, 3, 'arc 2 -> 3'), + (1, 4, 'arc 1 -> 4'), + (4, 5, 'arc 4 -> 5'), + (5, 1, 'arc 5 -> 1') +), +search_graph(f, t, label) as ( + select * from graph g + union all + select g.* + from graph g, search_graph sg + where g.f = sg.t +) cycle f, t set is_cycle to true default false using path +select f, t, label from search_graph; + f | t | label +---+---+------------ + 1 | 2 | arc 1 -> 2 + 1 | 3 | arc 1 -> 3 + 2 | 3 | arc 2 -> 3 + 1 | 4 | arc 1 -> 4 + 4 | 5 | arc 4 -> 5 + 5 | 1 | arc 5 -> 1 + 2 | 3 | arc 2 -> 3 + 4 | 5 | arc 4 -> 5 + 5 | 1 | arc 5 -> 1 + 1 | 4 | arc 1 -> 4 + 1 | 3 | arc 1 -> 3 + 1 | 2 | arc 1 -> 2 + 5 | 1 | arc 5 -> 1 + 1 | 4 | arc 1 -> 4 + 1 | 3 | arc 1 -> 3 + 1 | 2 | arc 1 -> 2 + 4 | 5 | arc 4 -> 5 + 2 | 3 | arc 2 -> 3 + 1 | 4 | arc 1 -> 4 + 1 | 3 | arc 1 -> 3 + 1 | 2 | arc 1 -> 2 + 4 | 5 | arc 4 -> 5 + 2 | 3 | arc 2 -> 3 + 5 | 1 | arc 5 -> 1 + 2 | 3 | arc 2 -> 3 +(25 rows) + +-- star expansion +with recursive a as ( + select 1 as b + union all + select * from a +) cycle b set c using p +select * from a; + b | c | p +---+---+----------- + 1 | f | {(1)} + 1 | t | {(1),(1)} +(2 rows) + +-- search+cycle +with recursive search_graph(f, t, label) as ( + select * from graph g + union all + select g.* + from graph g, search_graph sg + where g.f = sg.t +) search depth first by f, t set seq + cycle f, t set is_cycle using path +select * from search_graph; + f | t | label | seq | is_cycle | path +---+---+------------+-------------------------------------------+----------+------------------------------------------- + 1 | 2 | arc 1 -> 2 | {"(1,2)"} | f | {"(1,2)"} + 1 | 3 | arc 1 -> 3 | {"(1,3)"} | f | {"(1,3)"} + 2 | 3 | arc 2 -> 3 | {"(2,3)"} | f | {"(2,3)"} + 1 | 4 | arc 1 -> 4 | {"(1,4)"} | f | {"(1,4)"} + 4 | 5 | arc 4 -> 5 | {"(4,5)"} | f | {"(4,5)"} + 5 | 1 | arc 5 -> 1 | {"(5,1)"} | f | {"(5,1)"} + 1 | 2 | arc 1 -> 2 | {"(5,1)","(1,2)"} | f | {"(5,1)","(1,2)"} + 1 | 3 | arc 1 -> 3 | {"(5,1)","(1,3)"} | f | {"(5,1)","(1,3)"} + 1 | 4 | arc 1 -> 4 | {"(5,1)","(1,4)"} | f | {"(5,1)","(1,4)"} + 2 | 3 | arc 2 -> 3 | {"(1,2)","(2,3)"} | f | {"(1,2)","(2,3)"} + 4 | 5 | arc 4 -> 5 | {"(1,4)","(4,5)"} | f | {"(1,4)","(4,5)"} + 5 | 1 | arc 5 -> 1 | {"(4,5)","(5,1)"} | f | {"(4,5)","(5,1)"} + 1 | 2 | arc 1 -> 2 | {"(4,5)","(5,1)","(1,2)"} | f | {"(4,5)","(5,1)","(1,2)"} + 1 | 3 | arc 1 -> 3 | {"(4,5)","(5,1)","(1,3)"} | f | {"(4,5)","(5,1)","(1,3)"} + 1 | 4 | arc 1 -> 4 | {"(4,5)","(5,1)","(1,4)"} | f | {"(4,5)","(5,1)","(1,4)"} + 2 | 3 | arc 2 -> 3 | {"(5,1)","(1,2)","(2,3)"} | f | {"(5,1)","(1,2)","(2,3)"} + 4 | 5 | arc 4 -> 5 | {"(5,1)","(1,4)","(4,5)"} | f | {"(5,1)","(1,4)","(4,5)"} + 5 | 1 | arc 5 -> 1 | {"(1,4)","(4,5)","(5,1)"} | f | {"(1,4)","(4,5)","(5,1)"} + 1 | 2 | arc 1 -> 2 | {"(1,4)","(4,5)","(5,1)","(1,2)"} | f | {"(1,4)","(4,5)","(5,1)","(1,2)"} + 1 | 3 | arc 1 -> 3 | {"(1,4)","(4,5)","(5,1)","(1,3)"} | f | {"(1,4)","(4,5)","(5,1)","(1,3)"} + 1 | 4 | arc 1 -> 4 | {"(1,4)","(4,5)","(5,1)","(1,4)"} | t | {"(1,4)","(4,5)","(5,1)","(1,4)"} + 2 | 3 | arc 2 -> 3 | {"(4,5)","(5,1)","(1,2)","(2,3)"} | f | {"(4,5)","(5,1)","(1,2)","(2,3)"} + 4 | 5 | arc 4 -> 5 | {"(4,5)","(5,1)","(1,4)","(4,5)"} | t | {"(4,5)","(5,1)","(1,4)","(4,5)"} + 5 | 1 | arc 5 -> 1 | {"(5,1)","(1,4)","(4,5)","(5,1)"} | t | {"(5,1)","(1,4)","(4,5)","(5,1)"} + 2 | 3 | arc 2 -> 3 | {"(1,4)","(4,5)","(5,1)","(1,2)","(2,3)"} | f | {"(1,4)","(4,5)","(5,1)","(1,2)","(2,3)"} +(25 rows) + +with recursive search_graph(f, t, label) as ( + select * from graph g + union all + select g.* + from graph g, search_graph sg + where g.f = sg.t +) search breadth first by f, t set seq + cycle f, t set is_cycle using path +select * from search_graph; + f | t | label | seq | is_cycle | path +---+---+------------+---------+----------+------------------------------------------- + 1 | 2 | arc 1 -> 2 | (0,1,2) | f | {"(1,2)"} + 1 | 3 | arc 1 -> 3 | (0,1,3) | f | {"(1,3)"} + 2 | 3 | arc 2 -> 3 | (0,2,3) | f | {"(2,3)"} + 1 | 4 | arc 1 -> 4 | (0,1,4) | f | {"(1,4)"} + 4 | 5 | arc 4 -> 5 | (0,4,5) | f | {"(4,5)"} + 5 | 1 | arc 5 -> 1 | (0,5,1) | f | {"(5,1)"} + 1 | 2 | arc 1 -> 2 | (1,1,2) | f | {"(5,1)","(1,2)"} + 1 | 3 | arc 1 -> 3 | (1,1,3) | f | {"(5,1)","(1,3)"} + 1 | 4 | arc 1 -> 4 | (1,1,4) | f | {"(5,1)","(1,4)"} + 2 | 3 | arc 2 -> 3 | (1,2,3) | f | {"(1,2)","(2,3)"} + 4 | 5 | arc 4 -> 5 | (1,4,5) | f | {"(1,4)","(4,5)"} + 5 | 1 | arc 5 -> 1 | (1,5,1) | f | {"(4,5)","(5,1)"} + 1 | 2 | arc 1 -> 2 | (2,1,2) | f | {"(4,5)","(5,1)","(1,2)"} + 1 | 3 | arc 1 -> 3 | (2,1,3) | f | {"(4,5)","(5,1)","(1,3)"} + 1 | 4 | arc 1 -> 4 | (2,1,4) | f | {"(4,5)","(5,1)","(1,4)"} + 2 | 3 | arc 2 -> 3 | (2,2,3) | f | {"(5,1)","(1,2)","(2,3)"} + 4 | 5 | arc 4 -> 5 | (2,4,5) | f | {"(5,1)","(1,4)","(4,5)"} + 5 | 1 | arc 5 -> 1 | (2,5,1) | f | {"(1,4)","(4,5)","(5,1)"} + 1 | 2 | arc 1 -> 2 | (3,1,2) | f | {"(1,4)","(4,5)","(5,1)","(1,2)"} + 1 | 3 | arc 1 -> 3 | (3,1,3) | f | {"(1,4)","(4,5)","(5,1)","(1,3)"} + 1 | 4 | arc 1 -> 4 | (3,1,4) | t | {"(1,4)","(4,5)","(5,1)","(1,4)"} + 2 | 3 | arc 2 -> 3 | (3,2,3) | f | {"(4,5)","(5,1)","(1,2)","(2,3)"} + 4 | 5 | arc 4 -> 5 | (3,4,5) | t | {"(4,5)","(5,1)","(1,4)","(4,5)"} + 5 | 1 | arc 5 -> 1 | (3,5,1) | t | {"(5,1)","(1,4)","(4,5)","(5,1)"} + 2 | 3 | arc 2 -> 3 | (4,2,3) | f | {"(1,4)","(4,5)","(5,1)","(1,2)","(2,3)"} +(25 rows) + +-- various syntax errors +with recursive search_graph(f, t, label) as ( + select * from graph g + union all + select g.* + from graph g, search_graph sg + where g.f = sg.t +) cycle foo, tar set is_cycle using path +select * from search_graph; +ERROR: cycle column "foo" not in WITH query column list +LINE 7: ) cycle foo, tar set is_cycle using path + ^ +with recursive search_graph(f, t, label) as ( + select * from graph g + union all + select g.* + from graph g, search_graph sg + where g.f = sg.t +) cycle f, t set is_cycle to true default 55 using path +select * from search_graph; +ERROR: CYCLE types boolean and integer cannot be matched +LINE 7: ) cycle f, t set is_cycle to true default 55 using path + ^ +with recursive search_graph(f, t, label) as ( + select * from graph g + union all + select g.* + from graph g, search_graph sg + where g.f = sg.t +) cycle f, t set is_cycle to point '(1,1)' default point '(0,0)' using path +select * from search_graph; +ERROR: could not identify an equality operator for type point +with recursive search_graph(f, t, label) as ( + select * from graph g + union all + select g.* + from graph g, search_graph sg + where g.f = sg.t +) cycle f, t set label to true default false using path +select * from search_graph; +ERROR: cycle mark column name "label" already used in WITH query column list +LINE 7: ) cycle f, t set label to true default false using path + ^ +with recursive search_graph(f, t, label) as ( + select * from graph g + union all + select g.* + from graph g, search_graph sg + where g.f = sg.t +) cycle f, t set is_cycle to true default false using label +select * from search_graph; +ERROR: cycle path column name "label" already used in WITH query column list +LINE 7: ) cycle f, t set is_cycle to true default false using label + ^ +with recursive search_graph(f, t, label) as ( + select * from graph g + union all + select g.* + from graph g, search_graph sg + where g.f = sg.t +) cycle f, t set foo to true default false using foo +select * from search_graph; +ERROR: cycle mark column name and cycle path column name are the same +LINE 7: ) cycle f, t set foo to true default false using foo + ^ +with recursive search_graph(f, t, label) as ( + select * from graph g + union all + select g.* + from graph g, search_graph sg + where g.f = sg.t +) cycle f, t, f set is_cycle to true default false using path +select * from search_graph; +ERROR: cycle column "f" specified more than once +LINE 7: ) cycle f, t, f set is_cycle to true default false using pat... + ^ +with recursive search_graph(f, t, label) as ( + select * from graph g + union all + select g.* + from graph g, search_graph sg + where g.f = sg.t +) search depth first by f, t set foo + cycle f, t set foo to true default false using path +select * from search_graph; +ERROR: search sequence column name and cycle mark column name are the same +LINE 7: ) search depth first by f, t set foo + ^ +with recursive search_graph(f, t, label) as ( + select * from graph g + union all + select g.* + from graph g, search_graph sg + where g.f = sg.t +) search depth first by f, t set foo + cycle f, t set is_cycle to true default false using foo +select * from search_graph; +ERROR: search sequence column name and cycle path column name are the same +LINE 7: ) search depth first by f, t set foo + ^ +-- test ruleutils and view expansion +create temp view v_cycle1 as +with recursive search_graph(f, t, label) as ( + select * from graph g + union all + select g.* + from graph g, search_graph sg + where g.f = sg.t +) cycle f, t set is_cycle using path +select f, t, label from search_graph; +create temp view v_cycle2 as +with recursive search_graph(f, t, label) as ( + select * from graph g + union all + select g.* + from graph g, search_graph sg + where g.f = sg.t +) cycle f, t set is_cycle to 'Y' default 'N' using path +select f, t, label from search_graph; +select pg_get_viewdef('v_cycle1'); + pg_get_viewdef +------------------------------------------------ + WITH RECURSIVE search_graph(f, t, label) AS (+ + SELECT g.f, + + g.t, + + g.label + + FROM graph g + + UNION ALL + + SELECT g.f, + + g.t, + + g.label + + FROM graph g, + + search_graph sg + + WHERE (g.f = sg.t) + + ) CYCLE f, t SET is_cycle USING path + + SELECT f, + + t, + + label + + FROM search_graph; +(1 row) + +select pg_get_viewdef('v_cycle2'); + pg_get_viewdef +----------------------------------------------------------------------------- + WITH RECURSIVE search_graph(f, t, label) AS ( + + SELECT g.f, + + g.t, + + g.label + + FROM graph g + + UNION ALL + + SELECT g.f, + + g.t, + + g.label + + FROM graph g, + + search_graph sg + + WHERE (g.f = sg.t) + + ) CYCLE f, t SET is_cycle TO 'Y'::text DEFAULT 'N'::text USING path+ + SELECT f, + + t, + + label + + FROM search_graph; +(1 row) + +select * from v_cycle1; + f | t | label +---+---+------------ + 1 | 2 | arc 1 -> 2 + 1 | 3 | arc 1 -> 3 + 2 | 3 | arc 2 -> 3 + 1 | 4 | arc 1 -> 4 + 4 | 5 | arc 4 -> 5 + 5 | 1 | arc 5 -> 1 + 1 | 2 | arc 1 -> 2 + 1 | 3 | arc 1 -> 3 + 1 | 4 | arc 1 -> 4 + 2 | 3 | arc 2 -> 3 + 4 | 5 | arc 4 -> 5 + 5 | 1 | arc 5 -> 1 + 1 | 2 | arc 1 -> 2 + 1 | 3 | arc 1 -> 3 + 1 | 4 | arc 1 -> 4 + 2 | 3 | arc 2 -> 3 + 4 | 5 | arc 4 -> 5 + 5 | 1 | arc 5 -> 1 + 1 | 2 | arc 1 -> 2 + 1 | 3 | arc 1 -> 3 + 1 | 4 | arc 1 -> 4 + 2 | 3 | arc 2 -> 3 + 4 | 5 | arc 4 -> 5 + 5 | 1 | arc 5 -> 1 + 2 | 3 | arc 2 -> 3 +(25 rows) + +select * from v_cycle2; + f | t | label +---+---+------------ + 1 | 2 | arc 1 -> 2 + 1 | 3 | arc 1 -> 3 + 2 | 3 | arc 2 -> 3 + 1 | 4 | arc 1 -> 4 + 4 | 5 | arc 4 -> 5 + 5 | 1 | arc 5 -> 1 + 1 | 2 | arc 1 -> 2 + 1 | 3 | arc 1 -> 3 + 1 | 4 | arc 1 -> 4 + 2 | 3 | arc 2 -> 3 + 4 | 5 | arc 4 -> 5 + 5 | 1 | arc 5 -> 1 + 1 | 2 | arc 1 -> 2 + 1 | 3 | arc 1 -> 3 + 1 | 4 | arc 1 -> 4 + 2 | 3 | arc 2 -> 3 + 4 | 5 | arc 4 -> 5 + 5 | 1 | arc 5 -> 1 + 1 | 2 | arc 1 -> 2 + 1 | 3 | arc 1 -> 3 + 1 | 4 | arc 1 -> 4 + 2 | 3 | arc 2 -> 3 + 4 | 5 | arc 4 -> 5 + 5 | 1 | arc 5 -> 1 + 2 | 3 | arc 2 -> 3 +(25 rows) + +-- +-- test multiple WITH queries +-- +WITH RECURSIVE + y (id) AS (VALUES (1)), + x (id) AS (SELECT * FROM y UNION ALL SELECT id+1 FROM x WHERE id < 5) +SELECT * FROM x; + id +---- + 1 + 2 + 3 + 4 + 5 +(5 rows) + +-- forward reference OK +WITH RECURSIVE + x(id) AS (SELECT * FROM y UNION ALL SELECT id+1 FROM x WHERE id < 5), + y(id) AS (values (1)) + SELECT * FROM x; + id +---- + 1 + 2 + 3 + 4 + 5 +(5 rows) + +WITH RECURSIVE + x(id) AS + (VALUES (1) UNION ALL SELECT id+1 FROM x WHERE id < 5), + y(id) AS + (VALUES (1) UNION ALL SELECT id+1 FROM y WHERE id < 10) + SELECT y.*, x.* FROM y LEFT JOIN x USING (id); + id | id +----+---- + 1 | 1 + 2 | 2 + 3 | 3 + 4 | 4 + 5 | 5 + 6 | + 7 | + 8 | + 9 | + 10 | +(10 rows) + +WITH RECURSIVE + x(id) AS + (VALUES (1) UNION ALL SELECT id+1 FROM x WHERE id < 5), + y(id) AS + (VALUES (1) UNION ALL SELECT id+1 FROM x WHERE id < 10) + SELECT y.*, x.* FROM y LEFT JOIN x USING (id); + id | id +----+---- + 1 | 1 + 2 | 2 + 3 | 3 + 4 | 4 + 5 | 5 + 6 | +(6 rows) + +WITH RECURSIVE + x(id) AS + (SELECT 1 UNION ALL SELECT id+1 FROM x WHERE id < 3 ), + y(id) AS + (SELECT * FROM x UNION ALL SELECT * FROM x), + z(id) AS + (SELECT * FROM x UNION ALL SELECT id+1 FROM z WHERE id < 10) + SELECT * FROM z; + id +---- + 1 + 2 + 3 + 2 + 3 + 4 + 3 + 4 + 5 + 4 + 5 + 6 + 5 + 6 + 7 + 6 + 7 + 8 + 7 + 8 + 9 + 8 + 9 + 10 + 9 + 10 + 10 +(27 rows) + +WITH RECURSIVE + x(id) AS + (SELECT 1 UNION ALL SELECT id+1 FROM x WHERE id < 3 ), + y(id) AS + (SELECT * FROM x UNION ALL SELECT * FROM x), + z(id) AS + (SELECT * FROM y UNION ALL SELECT id+1 FROM z WHERE id < 10) + SELECT * FROM z; + id +---- + 1 + 2 + 3 + 1 + 2 + 3 + 2 + 3 + 4 + 2 + 3 + 4 + 3 + 4 + 5 + 3 + 4 + 5 + 4 + 5 + 6 + 4 + 5 + 6 + 5 + 6 + 7 + 5 + 6 + 7 + 6 + 7 + 8 + 6 + 7 + 8 + 7 + 8 + 9 + 7 + 8 + 9 + 8 + 9 + 10 + 8 + 9 + 10 + 9 + 10 + 9 + 10 + 10 + 10 +(54 rows) + +-- +-- Test WITH attached to a data-modifying statement +-- +CREATE TEMPORARY TABLE y (a INTEGER); +INSERT INTO y SELECT generate_series(1, 10); +WITH t AS ( + SELECT a FROM y +) +INSERT INTO y +SELECT a+20 FROM t RETURNING *; + a +---- + 21 + 22 + 23 + 24 + 25 + 26 + 27 + 28 + 29 + 30 +(10 rows) + +SELECT * FROM y; + a +---- + 1 + 2 + 3 + 4 + 5 + 6 + 7 + 8 + 9 + 10 + 21 + 22 + 23 + 24 + 25 + 26 + 27 + 28 + 29 + 30 +(20 rows) + +WITH t AS ( + SELECT a FROM y +) +UPDATE y SET a = y.a-10 FROM t WHERE y.a > 20 AND t.a = y.a RETURNING y.a; + a +---- + 11 + 12 + 13 + 14 + 15 + 16 + 17 + 18 + 19 + 20 +(10 rows) + +SELECT * FROM y; + a +---- + 1 + 2 + 3 + 4 + 5 + 6 + 7 + 8 + 9 + 10 + 11 + 12 + 13 + 14 + 15 + 16 + 17 + 18 + 19 + 20 +(20 rows) + +WITH RECURSIVE t(a) AS ( + SELECT 11 + UNION ALL + SELECT a+1 FROM t WHERE a < 50 +) +DELETE FROM y USING t WHERE t.a = y.a RETURNING y.a; + a +---- + 11 + 12 + 13 + 14 + 15 + 16 + 17 + 18 + 19 + 20 +(10 rows) + +SELECT * FROM y; + a +---- + 1 + 2 + 3 + 4 + 5 + 6 + 7 + 8 + 9 + 10 +(10 rows) + +DROP TABLE y; +-- +-- error cases +-- +WITH x(n, b) AS (SELECT 1) +SELECT * FROM x; +ERROR: WITH query "x" has 1 columns available but 2 columns specified +LINE 1: WITH x(n, b) AS (SELECT 1) + ^ +-- INTERSECT +WITH RECURSIVE x(n) AS (SELECT 1 INTERSECT SELECT n+1 FROM x) + SELECT * FROM x; +ERROR: recursive query "x" does not have the form non-recursive-term UNION [ALL] recursive-term +LINE 1: WITH RECURSIVE x(n) AS (SELECT 1 INTERSECT SELECT n+1 FROM x... + ^ +WITH RECURSIVE x(n) AS (SELECT 1 INTERSECT ALL SELECT n+1 FROM x) + SELECT * FROM x; +ERROR: recursive query "x" does not have the form non-recursive-term UNION [ALL] recursive-term +LINE 1: WITH RECURSIVE x(n) AS (SELECT 1 INTERSECT ALL SELECT n+1 FR... + ^ +-- EXCEPT +WITH RECURSIVE x(n) AS (SELECT 1 EXCEPT SELECT n+1 FROM x) + SELECT * FROM x; +ERROR: recursive query "x" does not have the form non-recursive-term UNION [ALL] recursive-term +LINE 1: WITH RECURSIVE x(n) AS (SELECT 1 EXCEPT SELECT n+1 FROM x) + ^ +WITH RECURSIVE x(n) AS (SELECT 1 EXCEPT ALL SELECT n+1 FROM x) + SELECT * FROM x; +ERROR: recursive query "x" does not have the form non-recursive-term UNION [ALL] recursive-term +LINE 1: WITH RECURSIVE x(n) AS (SELECT 1 EXCEPT ALL SELECT n+1 FROM ... + ^ +-- no non-recursive term +WITH RECURSIVE x(n) AS (SELECT n FROM x) + SELECT * FROM x; +ERROR: recursive query "x" does not have the form non-recursive-term UNION [ALL] recursive-term +LINE 1: WITH RECURSIVE x(n) AS (SELECT n FROM x) + ^ +-- recursive term in the left hand side (strictly speaking, should allow this) +WITH RECURSIVE x(n) AS (SELECT n FROM x UNION ALL SELECT 1) + SELECT * FROM x; +ERROR: recursive reference to query "x" must not appear within its non-recursive term +LINE 1: WITH RECURSIVE x(n) AS (SELECT n FROM x UNION ALL SELECT 1) + ^ +CREATE TEMPORARY TABLE y (a INTEGER); +INSERT INTO y SELECT generate_series(1, 10); +-- LEFT JOIN +WITH RECURSIVE x(n) AS (SELECT a FROM y WHERE a = 1 + UNION ALL + SELECT x.n+1 FROM y LEFT JOIN x ON x.n = y.a WHERE n < 10) +SELECT * FROM x; +ERROR: recursive reference to query "x" must not appear within an outer join +LINE 3: SELECT x.n+1 FROM y LEFT JOIN x ON x.n = y.a WHERE n < 10) + ^ +-- RIGHT JOIN +WITH RECURSIVE x(n) AS (SELECT a FROM y WHERE a = 1 + UNION ALL + SELECT x.n+1 FROM x RIGHT JOIN y ON x.n = y.a WHERE n < 10) +SELECT * FROM x; +ERROR: recursive reference to query "x" must not appear within an outer join +LINE 3: SELECT x.n+1 FROM x RIGHT JOIN y ON x.n = y.a WHERE n < 10) + ^ +-- FULL JOIN +WITH RECURSIVE x(n) AS (SELECT a FROM y WHERE a = 1 + UNION ALL + SELECT x.n+1 FROM x FULL JOIN y ON x.n = y.a WHERE n < 10) +SELECT * FROM x; +ERROR: recursive reference to query "x" must not appear within an outer join +LINE 3: SELECT x.n+1 FROM x FULL JOIN y ON x.n = y.a WHERE n < 10) + ^ +-- subquery +WITH RECURSIVE x(n) AS (SELECT 1 UNION ALL SELECT n+1 FROM x + WHERE n IN (SELECT * FROM x)) + SELECT * FROM x; +ERROR: recursive reference to query "x" must not appear within a subquery +LINE 2: WHERE n IN (SELECT * FROM x)) + ^ +-- aggregate functions +WITH RECURSIVE x(n) AS (SELECT 1 UNION ALL SELECT count(*) FROM x) + SELECT * FROM x; +ERROR: aggregate functions are not allowed in a recursive query's recursive term +LINE 1: WITH RECURSIVE x(n) AS (SELECT 1 UNION ALL SELECT count(*) F... + ^ +WITH RECURSIVE x(n) AS (SELECT 1 UNION ALL SELECT sum(n) FROM x) + SELECT * FROM x; +ERROR: aggregate functions are not allowed in a recursive query's recursive term +LINE 1: WITH RECURSIVE x(n) AS (SELECT 1 UNION ALL SELECT sum(n) FRO... + ^ +-- ORDER BY +WITH RECURSIVE x(n) AS (SELECT 1 UNION ALL SELECT n+1 FROM x ORDER BY 1) + SELECT * FROM x; +ERROR: ORDER BY in a recursive query is not implemented +LINE 1: ...VE x(n) AS (SELECT 1 UNION ALL SELECT n+1 FROM x ORDER BY 1) + ^ +-- LIMIT/OFFSET +WITH RECURSIVE x(n) AS (SELECT 1 UNION ALL SELECT n+1 FROM x LIMIT 10 OFFSET 1) + SELECT * FROM x; +ERROR: OFFSET in a recursive query is not implemented +LINE 1: ... AS (SELECT 1 UNION ALL SELECT n+1 FROM x LIMIT 10 OFFSET 1) + ^ +-- FOR UPDATE +WITH RECURSIVE x(n) AS (SELECT 1 UNION ALL SELECT n+1 FROM x FOR UPDATE) + SELECT * FROM x; +ERROR: FOR UPDATE/SHARE in a recursive query is not implemented +-- target list has a recursive query name +WITH RECURSIVE x(id) AS (values (1) + UNION ALL + SELECT (SELECT * FROM x) FROM x WHERE id < 5 +) SELECT * FROM x; +ERROR: recursive reference to query "x" must not appear within a subquery +LINE 3: SELECT (SELECT * FROM x) FROM x WHERE id < 5 + ^ +-- mutual recursive query (not implemented) +WITH RECURSIVE + x (id) AS (SELECT 1 UNION ALL SELECT id+1 FROM y WHERE id < 5), + y (id) AS (SELECT 1 UNION ALL SELECT id+1 FROM x WHERE id < 5) +SELECT * FROM x; +ERROR: mutual recursion between WITH items is not implemented +LINE 2: x (id) AS (SELECT 1 UNION ALL SELECT id+1 FROM y WHERE id ... + ^ +-- non-linear recursion is not allowed +WITH RECURSIVE foo(i) AS + (values (1) + UNION ALL + (SELECT i+1 FROM foo WHERE i < 10 + UNION ALL + SELECT i+1 FROM foo WHERE i < 5) +) SELECT * FROM foo; +ERROR: recursive reference to query "foo" must not appear more than once +LINE 6: SELECT i+1 FROM foo WHERE i < 5) + ^ +WITH RECURSIVE foo(i) AS + (values (1) + UNION ALL + SELECT * FROM + (SELECT i+1 FROM foo WHERE i < 10 + UNION ALL + SELECT i+1 FROM foo WHERE i < 5) AS t +) SELECT * FROM foo; +ERROR: recursive reference to query "foo" must not appear more than once +LINE 7: SELECT i+1 FROM foo WHERE i < 5) AS t + ^ +WITH RECURSIVE foo(i) AS + (values (1) + UNION ALL + (SELECT i+1 FROM foo WHERE i < 10 + EXCEPT + SELECT i+1 FROM foo WHERE i < 5) +) SELECT * FROM foo; +ERROR: recursive reference to query "foo" must not appear within EXCEPT +LINE 6: SELECT i+1 FROM foo WHERE i < 5) + ^ +WITH RECURSIVE foo(i) AS + (values (1) + UNION ALL + (SELECT i+1 FROM foo WHERE i < 10 + INTERSECT + SELECT i+1 FROM foo WHERE i < 5) +) SELECT * FROM foo; +ERROR: recursive reference to query "foo" must not appear more than once +LINE 6: SELECT i+1 FROM foo WHERE i < 5) + ^ +-- Wrong type induced from non-recursive term +WITH RECURSIVE foo(i) AS + (SELECT i FROM (VALUES(1),(2)) t(i) + UNION ALL + SELECT (i+1)::numeric(10,0) FROM foo WHERE i < 10) +SELECT * FROM foo; +ERROR: recursive query "foo" column 1 has type integer in non-recursive term but type numeric overall +LINE 2: (SELECT i FROM (VALUES(1),(2)) t(i) + ^ +HINT: Cast the output of the non-recursive term to the correct type. +-- rejects different typmod, too (should we allow this?) +WITH RECURSIVE foo(i) AS + (SELECT i::numeric(3,0) FROM (VALUES(1),(2)) t(i) + UNION ALL + SELECT (i+1)::numeric(10,0) FROM foo WHERE i < 10) +SELECT * FROM foo; +ERROR: recursive query "foo" column 1 has type numeric(3,0) in non-recursive term but type numeric overall +LINE 2: (SELECT i::numeric(3,0) FROM (VALUES(1),(2)) t(i) + ^ +HINT: Cast the output of the non-recursive term to the correct type. +-- disallow OLD/NEW reference in CTE +CREATE TEMPORARY TABLE x (n integer); +CREATE RULE r2 AS ON UPDATE TO x DO INSTEAD + WITH t AS (SELECT OLD.*) UPDATE y SET a = t.n FROM t; +ERROR: cannot refer to OLD within WITH query +-- +-- test for bug #4902 +-- +with cte(foo) as ( values(42) ) values((select foo from cte)); + column1 +--------- + 42 +(1 row) + +with cte(foo) as ( select 42 ) select * from ((select foo from cte)) q; + foo +----- + 42 +(1 row) + +-- test CTE referencing an outer-level variable (to see that changed-parameter +-- signaling still works properly after fixing this bug) +select ( with cte(foo) as ( values(f1) ) + select (select foo from cte) ) +from int4_tbl; + foo +------------- + 0 + 123456 + -123456 + 2147483647 + -2147483647 +(5 rows) + +select ( with cte(foo) as ( values(f1) ) + values((select foo from cte)) ) +from int4_tbl; + column1 +------------- + 0 + 123456 + -123456 + 2147483647 + -2147483647 +(5 rows) + +-- +-- test for nested-recursive-WITH bug +-- +WITH RECURSIVE t(j) AS ( + WITH RECURSIVE s(i) AS ( + VALUES (1) + UNION ALL + SELECT i+1 FROM s WHERE i < 10 + ) + SELECT i FROM s + UNION ALL + SELECT j+1 FROM t WHERE j < 10 +) +SELECT * FROM t; + j +---- + 1 + 2 + 3 + 4 + 5 + 6 + 7 + 8 + 9 + 10 + 2 + 3 + 4 + 5 + 6 + 7 + 8 + 9 + 10 + 3 + 4 + 5 + 6 + 7 + 8 + 9 + 10 + 4 + 5 + 6 + 7 + 8 + 9 + 10 + 5 + 6 + 7 + 8 + 9 + 10 + 6 + 7 + 8 + 9 + 10 + 7 + 8 + 9 + 10 + 8 + 9 + 10 + 9 + 10 + 10 +(55 rows) + +-- +-- test WITH attached to intermediate-level set operation +-- +WITH outermost(x) AS ( + SELECT 1 + UNION (WITH innermost as (SELECT 2) + SELECT * FROM innermost + UNION SELECT 3) +) +SELECT * FROM outermost ORDER BY 1; + x +--- + 1 + 2 + 3 +(3 rows) + +WITH outermost(x) AS ( + SELECT 1 + UNION (WITH innermost as (SELECT 2) + SELECT * FROM outermost -- fail + UNION SELECT * FROM innermost) +) +SELECT * FROM outermost ORDER BY 1; +ERROR: relation "outermost" does not exist +LINE 4: SELECT * FROM outermost -- fail + ^ +DETAIL: There is a WITH item named "outermost", but it cannot be referenced from this part of the query. +HINT: Use WITH RECURSIVE, or re-order the WITH items to remove forward references. +WITH RECURSIVE outermost(x) AS ( + SELECT 1 + UNION (WITH innermost as (SELECT 2) + SELECT * FROM outermost + UNION SELECT * FROM innermost) +) +SELECT * FROM outermost ORDER BY 1; + x +--- + 1 + 2 +(2 rows) + +WITH RECURSIVE outermost(x) AS ( + WITH innermost as (SELECT 2 FROM outermost) -- fail + SELECT * FROM innermost + UNION SELECT * from outermost +) +SELECT * FROM outermost ORDER BY 1; +ERROR: recursive reference to query "outermost" must not appear within a subquery +LINE 2: WITH innermost as (SELECT 2 FROM outermost) -- fail + ^ +-- +-- This test will fail with the old implementation of PARAM_EXEC parameter +-- assignment, because the "q1" Var passed down to A's targetlist subselect +-- looks exactly like the "A.id" Var passed down to C's subselect, causing +-- the old code to give them the same runtime PARAM_EXEC slot. But the +-- lifespans of the two parameters overlap, thanks to B also reading A. +-- +with +A as ( select q2 as id, (select q1) as x from int8_tbl ), +B as ( select id, row_number() over (partition by id) as r from A ), +C as ( select A.id, array(select B.id from B where B.id = A.id) from A ) +select * from C; + id | array +-------------------+------------------------------------- + 456 | {456} + 4567890123456789 | {4567890123456789,4567890123456789} + 123 | {123} + 4567890123456789 | {4567890123456789,4567890123456789} + -4567890123456789 | {-4567890123456789} +(5 rows) + +-- +-- Test CTEs read in non-initialization orders +-- +WITH RECURSIVE + tab(id_key,link) AS (VALUES (1,17), (2,17), (3,17), (4,17), (6,17), (5,17)), + iter (id_key, row_type, link) AS ( + SELECT 0, 'base', 17 + UNION ALL ( + WITH remaining(id_key, row_type, link, min) AS ( + SELECT tab.id_key, 'true'::text, iter.link, MIN(tab.id_key) OVER () + FROM tab INNER JOIN iter USING (link) + WHERE tab.id_key > iter.id_key + ), + first_remaining AS ( + SELECT id_key, row_type, link + FROM remaining + WHERE id_key=min + ), + effect AS ( + SELECT tab.id_key, 'new'::text, tab.link + FROM first_remaining e INNER JOIN tab ON e.id_key=tab.id_key + WHERE e.row_type = 'false' + ) + SELECT * FROM first_remaining + UNION ALL SELECT * FROM effect + ) + ) +SELECT * FROM iter; + id_key | row_type | link +--------+----------+------ + 0 | base | 17 + 1 | true | 17 + 2 | true | 17 + 3 | true | 17 + 4 | true | 17 + 5 | true | 17 + 6 | true | 17 +(7 rows) + +WITH RECURSIVE + tab(id_key,link) AS (VALUES (1,17), (2,17), (3,17), (4,17), (6,17), (5,17)), + iter (id_key, row_type, link) AS ( + SELECT 0, 'base', 17 + UNION ( + WITH remaining(id_key, row_type, link, min) AS ( + SELECT tab.id_key, 'true'::text, iter.link, MIN(tab.id_key) OVER () + FROM tab INNER JOIN iter USING (link) + WHERE tab.id_key > iter.id_key + ), + first_remaining AS ( + SELECT id_key, row_type, link + FROM remaining + WHERE id_key=min + ), + effect AS ( + SELECT tab.id_key, 'new'::text, tab.link + FROM first_remaining e INNER JOIN tab ON e.id_key=tab.id_key + WHERE e.row_type = 'false' + ) + SELECT * FROM first_remaining + UNION ALL SELECT * FROM effect + ) + ) +SELECT * FROM iter; + id_key | row_type | link +--------+----------+------ + 0 | base | 17 + 1 | true | 17 + 2 | true | 17 + 3 | true | 17 + 4 | true | 17 + 5 | true | 17 + 6 | true | 17 +(7 rows) + +-- +-- Data-modifying statements in WITH +-- +-- INSERT ... RETURNING +WITH t AS ( + INSERT INTO y + VALUES + (11), + (12), + (13), + (14), + (15), + (16), + (17), + (18), + (19), + (20) + RETURNING * +) +SELECT * FROM t; + a +---- + 11 + 12 + 13 + 14 + 15 + 16 + 17 + 18 + 19 + 20 +(10 rows) + +SELECT * FROM y; + a +---- + 1 + 2 + 3 + 4 + 5 + 6 + 7 + 8 + 9 + 10 + 11 + 12 + 13 + 14 + 15 + 16 + 17 + 18 + 19 + 20 +(20 rows) + +-- UPDATE ... RETURNING +WITH t AS ( + UPDATE y + SET a=a+1 + RETURNING * +) +SELECT * FROM t; + a +---- + 2 + 3 + 4 + 5 + 6 + 7 + 8 + 9 + 10 + 11 + 12 + 13 + 14 + 15 + 16 + 17 + 18 + 19 + 20 + 21 +(20 rows) + +SELECT * FROM y; + a +---- + 2 + 3 + 4 + 5 + 6 + 7 + 8 + 9 + 10 + 11 + 12 + 13 + 14 + 15 + 16 + 17 + 18 + 19 + 20 + 21 +(20 rows) + +-- DELETE ... RETURNING +WITH t AS ( + DELETE FROM y + WHERE a <= 10 + RETURNING * +) +SELECT * FROM t; + a +---- + 2 + 3 + 4 + 5 + 6 + 7 + 8 + 9 + 10 +(9 rows) + +SELECT * FROM y; + a +---- + 11 + 12 + 13 + 14 + 15 + 16 + 17 + 18 + 19 + 20 + 21 +(11 rows) + +-- forward reference +WITH RECURSIVE t AS ( + INSERT INTO y + SELECT a+5 FROM t2 WHERE a > 5 + RETURNING * +), t2 AS ( + UPDATE y SET a=a-11 RETURNING * +) +SELECT * FROM t +UNION ALL +SELECT * FROM t2; + a +---- + 11 + 12 + 13 + 14 + 15 + 0 + 1 + 2 + 3 + 4 + 5 + 6 + 7 + 8 + 9 + 10 +(16 rows) + +SELECT * FROM y; + a +---- + 0 + 1 + 2 + 3 + 4 + 5 + 6 + 11 + 7 + 12 + 8 + 13 + 9 + 14 + 10 + 15 +(16 rows) + +-- unconditional DO INSTEAD rule +CREATE RULE y_rule AS ON DELETE TO y DO INSTEAD + INSERT INTO y VALUES(42) RETURNING *; +WITH t AS ( + DELETE FROM y RETURNING * +) +SELECT * FROM t; + a +---- + 42 +(1 row) + +SELECT * FROM y; + a +---- + 0 + 1 + 2 + 3 + 4 + 5 + 6 + 11 + 7 + 12 + 8 + 13 + 9 + 14 + 10 + 15 + 42 +(17 rows) + +DROP RULE y_rule ON y; +-- check merging of outer CTE with CTE in a rule action +CREATE TEMP TABLE bug6051 AS + select i from generate_series(1,3) as t(i); +SELECT * FROM bug6051; + i +--- + 1 + 2 + 3 +(3 rows) + +WITH t1 AS ( DELETE FROM bug6051 RETURNING * ) +INSERT INTO bug6051 SELECT * FROM t1; +SELECT * FROM bug6051; + i +--- + 1 + 2 + 3 +(3 rows) + +CREATE TEMP TABLE bug6051_2 (i int); +CREATE RULE bug6051_ins AS ON INSERT TO bug6051 DO INSTEAD + INSERT INTO bug6051_2 + VALUES(NEW.i); +WITH t1 AS ( DELETE FROM bug6051 RETURNING * ) +INSERT INTO bug6051 SELECT * FROM t1; +SELECT * FROM bug6051; + i +--- +(0 rows) + +SELECT * FROM bug6051_2; + i +--- + 1 + 2 + 3 +(3 rows) + +-- check INSERT ... SELECT rule actions are disallowed on commands +-- that have modifyingCTEs +CREATE OR REPLACE RULE bug6051_ins AS ON INSERT TO bug6051 DO INSTEAD + INSERT INTO bug6051_2 + SELECT NEW.i; +WITH t1 AS ( DELETE FROM bug6051 RETURNING * ) +INSERT INTO bug6051 SELECT * FROM t1; +ERROR: INSERT ... SELECT rule actions are not supported for queries having data-modifying statements in WITH +-- silly example to verify that hasModifyingCTE flag is propagated +CREATE TEMP TABLE bug6051_3 AS + SELECT a FROM generate_series(11,13) AS a; +CREATE RULE bug6051_3_ins AS ON INSERT TO bug6051_3 DO INSTEAD + SELECT i FROM bug6051_2; +BEGIN; SET LOCAL debug_parallel_query = on; +WITH t1 AS ( DELETE FROM bug6051_3 RETURNING * ) + INSERT INTO bug6051_3 SELECT * FROM t1; + i +--- + 1 + 2 + 3 + 1 + 2 + 3 + 1 + 2 + 3 +(9 rows) + +COMMIT; +SELECT * FROM bug6051_3; + a +--- +(0 rows) + +-- check case where CTE reference is removed due to optimization +EXPLAIN (VERBOSE, COSTS OFF) +SELECT q1 FROM +( + WITH t_cte AS (SELECT * FROM int8_tbl t) + SELECT q1, (SELECT q2 FROM t_cte WHERE t_cte.q1 = i8.q1) AS t_sub + FROM int8_tbl i8 +) ss; + QUERY PLAN +-------------------------------------- + Subquery Scan on ss + Output: ss.q1 + -> Seq Scan on public.int8_tbl i8 + Output: i8.q1, NULL::bigint +(4 rows) + +SELECT q1 FROM +( + WITH t_cte AS (SELECT * FROM int8_tbl t) + SELECT q1, (SELECT q2 FROM t_cte WHERE t_cte.q1 = i8.q1) AS t_sub + FROM int8_tbl i8 +) ss; + q1 +------------------ + 123 + 123 + 4567890123456789 + 4567890123456789 + 4567890123456789 +(5 rows) + +EXPLAIN (VERBOSE, COSTS OFF) +SELECT q1 FROM +( + WITH t_cte AS MATERIALIZED (SELECT * FROM int8_tbl t) + SELECT q1, (SELECT q2 FROM t_cte WHERE t_cte.q1 = i8.q1) AS t_sub + FROM int8_tbl i8 +) ss; + QUERY PLAN +--------------------------------------------- + Subquery Scan on ss + Output: ss.q1 + -> Seq Scan on public.int8_tbl i8 + Output: i8.q1, NULL::bigint + CTE t_cte + -> Seq Scan on public.int8_tbl t + Output: t.q1, t.q2 +(7 rows) + +SELECT q1 FROM +( + WITH t_cte AS MATERIALIZED (SELECT * FROM int8_tbl t) + SELECT q1, (SELECT q2 FROM t_cte WHERE t_cte.q1 = i8.q1) AS t_sub + FROM int8_tbl i8 +) ss; + q1 +------------------ + 123 + 123 + 4567890123456789 + 4567890123456789 + 4567890123456789 +(5 rows) + +-- a truly recursive CTE in the same list +WITH RECURSIVE t(a) AS ( + SELECT 0 + UNION ALL + SELECT a+1 FROM t WHERE a+1 < 5 +), t2 as ( + INSERT INTO y + SELECT * FROM t RETURNING * +) +SELECT * FROM t2 JOIN y USING (a) ORDER BY a; + a +--- + 0 + 1 + 2 + 3 + 4 +(5 rows) + +SELECT * FROM y; + a +---- + 0 + 1 + 2 + 3 + 4 + 5 + 6 + 11 + 7 + 12 + 8 + 13 + 9 + 14 + 10 + 15 + 42 + 0 + 1 + 2 + 3 + 4 +(22 rows) + +-- data-modifying WITH in a modifying statement +WITH t AS ( + DELETE FROM y + WHERE a <= 10 + RETURNING * +) +INSERT INTO y SELECT -a FROM t RETURNING *; + a +----- + 0 + -1 + -2 + -3 + -4 + -5 + -6 + -7 + -8 + -9 + -10 + 0 + -1 + -2 + -3 + -4 +(16 rows) + +SELECT * FROM y; + a +----- + 11 + 12 + 13 + 14 + 15 + 42 + 0 + -1 + -2 + -3 + -4 + -5 + -6 + -7 + -8 + -9 + -10 + 0 + -1 + -2 + -3 + -4 +(22 rows) + +-- check that WITH query is run to completion even if outer query isn't +WITH t AS ( + UPDATE y SET a = a * 100 RETURNING * +) +SELECT * FROM t LIMIT 10; + a +------ + 1100 + 1200 + 1300 + 1400 + 1500 + 4200 + 0 + -100 + -200 + -300 +(10 rows) + +SELECT * FROM y; + a +------- + 1100 + 1200 + 1300 + 1400 + 1500 + 4200 + 0 + -100 + -200 + -300 + -400 + -500 + -600 + -700 + -800 + -900 + -1000 + 0 + -100 + -200 + -300 + -400 +(22 rows) + +-- data-modifying WITH containing INSERT...ON CONFLICT DO UPDATE +CREATE TABLE withz AS SELECT i AS k, (i || ' v')::text v FROM generate_series(1, 16, 3) i; +ALTER TABLE withz ADD UNIQUE (k); +WITH t AS ( + INSERT INTO withz SELECT i, 'insert' + FROM generate_series(0, 16) i + ON CONFLICT (k) DO UPDATE SET v = withz.v || ', now update' + RETURNING * +) +SELECT * FROM t JOIN y ON t.k = y.a ORDER BY a, k; + k | v | a +---+--------+--- + 0 | insert | 0 + 0 | insert | 0 +(2 rows) + +-- Test EXCLUDED.* reference within CTE +WITH aa AS ( + INSERT INTO withz VALUES(1, 5) ON CONFLICT (k) DO UPDATE SET v = EXCLUDED.v + WHERE withz.k != EXCLUDED.k + RETURNING * +) +SELECT * FROM aa; + k | v +---+--- +(0 rows) + +-- New query/snapshot demonstrates side-effects of previous query. +SELECT * FROM withz ORDER BY k; + k | v +----+------------------ + 0 | insert + 1 | 1 v, now update + 2 | insert + 3 | insert + 4 | 4 v, now update + 5 | insert + 6 | insert + 7 | 7 v, now update + 8 | insert + 9 | insert + 10 | 10 v, now update + 11 | insert + 12 | insert + 13 | 13 v, now update + 14 | insert + 15 | insert + 16 | 16 v, now update +(17 rows) + +-- +-- Ensure subqueries within the update clause work, even if they +-- reference outside values +-- +WITH aa AS (SELECT 1 a, 2 b) +INSERT INTO withz VALUES(1, 'insert') +ON CONFLICT (k) DO UPDATE SET v = (SELECT b || ' update' FROM aa WHERE a = 1 LIMIT 1); +WITH aa AS (SELECT 1 a, 2 b) +INSERT INTO withz VALUES(1, 'insert') +ON CONFLICT (k) DO UPDATE SET v = ' update' WHERE withz.k = (SELECT a FROM aa); +WITH aa AS (SELECT 1 a, 2 b) +INSERT INTO withz VALUES(1, 'insert') +ON CONFLICT (k) DO UPDATE SET v = (SELECT b || ' update' FROM aa WHERE a = 1 LIMIT 1); +WITH aa AS (SELECT 'a' a, 'b' b UNION ALL SELECT 'a' a, 'b' b) +INSERT INTO withz VALUES(1, 'insert') +ON CONFLICT (k) DO UPDATE SET v = (SELECT b || ' update' FROM aa WHERE a = 'a' LIMIT 1); +WITH aa AS (SELECT 1 a, 2 b) +INSERT INTO withz VALUES(1, (SELECT b || ' insert' FROM aa WHERE a = 1 )) +ON CONFLICT (k) DO UPDATE SET v = (SELECT b || ' update' FROM aa WHERE a = 1 LIMIT 1); +-- Update a row more than once, in different parts of a wCTE. That is +-- an allowed, presumably very rare, edge case, but since it was +-- broken in the past, having a test seems worthwhile. +WITH simpletup AS ( + SELECT 2 k, 'Green' v), +upsert_cte AS ( + INSERT INTO withz VALUES(2, 'Blue') ON CONFLICT (k) DO + UPDATE SET (k, v) = (SELECT k, v FROM simpletup WHERE simpletup.k = withz.k) + RETURNING k, v) +INSERT INTO withz VALUES(2, 'Red') ON CONFLICT (k) DO +UPDATE SET (k, v) = (SELECT k, v FROM upsert_cte WHERE upsert_cte.k = withz.k) +RETURNING k, v; + k | v +---+--- +(0 rows) + +DROP TABLE withz; +-- WITH referenced by MERGE statement +CREATE TABLE m AS SELECT i AS k, (i || ' v')::text v FROM generate_series(1, 16, 3) i; +ALTER TABLE m ADD UNIQUE (k); +WITH RECURSIVE cte_basic AS (SELECT 1 a, 'cte_basic val' b) +MERGE INTO m USING (select 0 k, 'merge source SubPlan' v) o ON m.k=o.k +WHEN MATCHED THEN UPDATE SET v = (SELECT b || ' merge update' FROM cte_basic WHERE cte_basic.a = m.k LIMIT 1) +WHEN NOT MATCHED THEN INSERT VALUES(o.k, o.v); +ERROR: WITH RECURSIVE is not supported for MERGE statement +-- Basic: +WITH cte_basic AS MATERIALIZED (SELECT 1 a, 'cte_basic val' b) +MERGE INTO m USING (select 0 k, 'merge source SubPlan' v offset 0) o ON m.k=o.k +WHEN MATCHED THEN UPDATE SET v = (SELECT b || ' merge update' FROM cte_basic WHERE cte_basic.a = m.k LIMIT 1) +WHEN NOT MATCHED THEN INSERT VALUES(o.k, o.v); +-- Examine +SELECT * FROM m where k = 0; + k | v +---+---------------------- + 0 | merge source SubPlan +(1 row) + +-- See EXPLAIN output for same query: +EXPLAIN (VERBOSE, COSTS OFF) +WITH cte_basic AS MATERIALIZED (SELECT 1 a, 'cte_basic val' b) +MERGE INTO m USING (select 0 k, 'merge source SubPlan' v offset 0) o ON m.k=o.k +WHEN MATCHED THEN UPDATE SET v = (SELECT b || ' merge update' FROM cte_basic WHERE cte_basic.a = m.k LIMIT 1) +WHEN NOT MATCHED THEN INSERT VALUES(o.k, o.v); + QUERY PLAN +------------------------------------------------------------------- + Merge on public.m + CTE cte_basic + -> Result + Output: 1, 'cte_basic val'::text + -> Hash Right Join + Output: m.ctid, o.k, o.v, o.* + Hash Cond: (m.k = o.k) + -> Seq Scan on public.m + Output: m.ctid, m.k + -> Hash + Output: o.k, o.v, o.* + -> Subquery Scan on o + Output: o.k, o.v, o.* + -> Result + Output: 0, 'merge source SubPlan'::text + SubPlan 2 + -> Limit + Output: ((cte_basic.b || ' merge update'::text)) + -> CTE Scan on cte_basic + Output: (cte_basic.b || ' merge update'::text) + Filter: (cte_basic.a = m.k) +(21 rows) + +-- InitPlan +WITH cte_init AS MATERIALIZED (SELECT 1 a, 'cte_init val' b) +MERGE INTO m USING (select 1 k, 'merge source InitPlan' v offset 0) o ON m.k=o.k +WHEN MATCHED THEN UPDATE SET v = (SELECT b || ' merge update' FROM cte_init WHERE a = 1 LIMIT 1) +WHEN NOT MATCHED THEN INSERT VALUES(o.k, o.v); +-- Examine +SELECT * FROM m where k = 1; + k | v +---+--------------------------- + 1 | cte_init val merge update +(1 row) + +-- See EXPLAIN output for same query: +EXPLAIN (VERBOSE, COSTS OFF) +WITH cte_init AS MATERIALIZED (SELECT 1 a, 'cte_init val' b) +MERGE INTO m USING (select 1 k, 'merge source InitPlan' v offset 0) o ON m.k=o.k +WHEN MATCHED THEN UPDATE SET v = (SELECT b || ' merge update' FROM cte_init WHERE a = 1 LIMIT 1) +WHEN NOT MATCHED THEN INSERT VALUES(o.k, o.v); + QUERY PLAN +-------------------------------------------------------------------- + Merge on public.m + CTE cte_init + -> Result + Output: 1, 'cte_init val'::text + InitPlan 2 (returns $1) + -> Limit + Output: ((cte_init.b || ' merge update'::text)) + -> CTE Scan on cte_init + Output: (cte_init.b || ' merge update'::text) + Filter: (cte_init.a = 1) + -> Hash Right Join + Output: m.ctid, o.k, o.v, o.* + Hash Cond: (m.k = o.k) + -> Seq Scan on public.m + Output: m.ctid, m.k + -> Hash + Output: o.k, o.v, o.* + -> Subquery Scan on o + Output: o.k, o.v, o.* + -> Result + Output: 1, 'merge source InitPlan'::text +(21 rows) + +-- MERGE source comes from CTE: +WITH merge_source_cte AS MATERIALIZED (SELECT 15 a, 'merge_source_cte val' b) +MERGE INTO m USING (select * from merge_source_cte) o ON m.k=o.a +WHEN MATCHED THEN UPDATE SET v = (SELECT b || merge_source_cte.*::text || ' merge update' FROM merge_source_cte WHERE a = 15) +WHEN NOT MATCHED THEN INSERT VALUES(o.a, o.b || (SELECT merge_source_cte.*::text || ' merge insert' FROM merge_source_cte)); +-- Examine +SELECT * FROM m where k = 15; + k | v +----+-------------------------------------------------------------- + 15 | merge_source_cte val(15,"merge_source_cte val") merge insert +(1 row) + +-- See EXPLAIN output for same query: +EXPLAIN (VERBOSE, COSTS OFF) +WITH merge_source_cte AS MATERIALIZED (SELECT 15 a, 'merge_source_cte val' b) +MERGE INTO m USING (select * from merge_source_cte) o ON m.k=o.a +WHEN MATCHED THEN UPDATE SET v = (SELECT b || merge_source_cte.*::text || ' merge update' FROM merge_source_cte WHERE a = 15) +WHEN NOT MATCHED THEN INSERT VALUES(o.a, o.b || (SELECT merge_source_cte.*::text || ' merge insert' FROM merge_source_cte)); + QUERY PLAN +----------------------------------------------------------------------------------------------------- + Merge on public.m + CTE merge_source_cte + -> Result + Output: 15, 'merge_source_cte val'::text + InitPlan 2 (returns $1) + -> CTE Scan on merge_source_cte merge_source_cte_1 + Output: ((merge_source_cte_1.b || (merge_source_cte_1.*)::text) || ' merge update'::text) + Filter: (merge_source_cte_1.a = 15) + InitPlan 3 (returns $2) + -> CTE Scan on merge_source_cte merge_source_cte_2 + Output: ((merge_source_cte_2.*)::text || ' merge insert'::text) + -> Hash Right Join + Output: m.ctid, merge_source_cte.a, merge_source_cte.b, merge_source_cte.* + Hash Cond: (m.k = merge_source_cte.a) + -> Seq Scan on public.m + Output: m.ctid, m.k + -> Hash + Output: merge_source_cte.a, merge_source_cte.b, merge_source_cte.* + -> CTE Scan on merge_source_cte + Output: merge_source_cte.a, merge_source_cte.b, merge_source_cte.* +(20 rows) + +DROP TABLE m; +-- check that run to completion happens in proper ordering +TRUNCATE TABLE y; +INSERT INTO y SELECT generate_series(1, 3); +CREATE TEMPORARY TABLE yy (a INTEGER); +WITH RECURSIVE t1 AS ( + INSERT INTO y SELECT * FROM y RETURNING * +), t2 AS ( + INSERT INTO yy SELECT * FROM t1 RETURNING * +) +SELECT 1; + ?column? +---------- + 1 +(1 row) + +SELECT * FROM y; + a +--- + 1 + 2 + 3 + 1 + 2 + 3 +(6 rows) + +SELECT * FROM yy; + a +--- + 1 + 2 + 3 +(3 rows) + +WITH RECURSIVE t1 AS ( + INSERT INTO yy SELECT * FROM t2 RETURNING * +), t2 AS ( + INSERT INTO y SELECT * FROM y RETURNING * +) +SELECT 1; + ?column? +---------- + 1 +(1 row) + +SELECT * FROM y; + a +--- + 1 + 2 + 3 + 1 + 2 + 3 + 1 + 2 + 3 + 1 + 2 + 3 +(12 rows) + +SELECT * FROM yy; + a +--- + 1 + 2 + 3 + 1 + 2 + 3 + 1 + 2 + 3 +(9 rows) + +-- triggers +TRUNCATE TABLE y; +INSERT INTO y SELECT generate_series(1, 10); +CREATE FUNCTION y_trigger() RETURNS trigger AS $$ +begin + raise notice 'y_trigger: a = %', new.a; + return new; +end; +$$ LANGUAGE plpgsql; +CREATE TRIGGER y_trig BEFORE INSERT ON y FOR EACH ROW + EXECUTE PROCEDURE y_trigger(); +WITH t AS ( + INSERT INTO y + VALUES + (21), + (22), + (23) + RETURNING * +) +SELECT * FROM t; +NOTICE: y_trigger: a = 21 +NOTICE: y_trigger: a = 22 +NOTICE: y_trigger: a = 23 + a +---- + 21 + 22 + 23 +(3 rows) + +SELECT * FROM y; + a +---- + 1 + 2 + 3 + 4 + 5 + 6 + 7 + 8 + 9 + 10 + 21 + 22 + 23 +(13 rows) + +DROP TRIGGER y_trig ON y; +CREATE TRIGGER y_trig AFTER INSERT ON y FOR EACH ROW + EXECUTE PROCEDURE y_trigger(); +WITH t AS ( + INSERT INTO y + VALUES + (31), + (32), + (33) + RETURNING * +) +SELECT * FROM t LIMIT 1; +NOTICE: y_trigger: a = 31 +NOTICE: y_trigger: a = 32 +NOTICE: y_trigger: a = 33 + a +---- + 31 +(1 row) + +SELECT * FROM y; + a +---- + 1 + 2 + 3 + 4 + 5 + 6 + 7 + 8 + 9 + 10 + 21 + 22 + 23 + 31 + 32 + 33 +(16 rows) + +DROP TRIGGER y_trig ON y; +CREATE OR REPLACE FUNCTION y_trigger() RETURNS trigger AS $$ +begin + raise notice 'y_trigger'; + return null; +end; +$$ LANGUAGE plpgsql; +CREATE TRIGGER y_trig AFTER INSERT ON y FOR EACH STATEMENT + EXECUTE PROCEDURE y_trigger(); +WITH t AS ( + INSERT INTO y + VALUES + (41), + (42), + (43) + RETURNING * +) +SELECT * FROM t; +NOTICE: y_trigger + a +---- + 41 + 42 + 43 +(3 rows) + +SELECT * FROM y; + a +---- + 1 + 2 + 3 + 4 + 5 + 6 + 7 + 8 + 9 + 10 + 21 + 22 + 23 + 31 + 32 + 33 + 41 + 42 + 43 +(19 rows) + +DROP TRIGGER y_trig ON y; +DROP FUNCTION y_trigger(); +-- WITH attached to inherited UPDATE or DELETE +CREATE TEMP TABLE parent ( id int, val text ); +CREATE TEMP TABLE child1 ( ) INHERITS ( parent ); +CREATE TEMP TABLE child2 ( ) INHERITS ( parent ); +INSERT INTO parent VALUES ( 1, 'p1' ); +INSERT INTO child1 VALUES ( 11, 'c11' ),( 12, 'c12' ); +INSERT INTO child2 VALUES ( 23, 'c21' ),( 24, 'c22' ); +WITH rcte AS ( SELECT sum(id) AS totalid FROM parent ) +UPDATE parent SET id = id + totalid FROM rcte; +SELECT * FROM parent; + id | val +----+----- + 72 | p1 + 82 | c11 + 83 | c12 + 94 | c21 + 95 | c22 +(5 rows) + +WITH wcte AS ( INSERT INTO child1 VALUES ( 42, 'new' ) RETURNING id AS newid ) +UPDATE parent SET id = id + newid FROM wcte; +SELECT * FROM parent; + id | val +-----+----- + 114 | p1 + 42 | new + 124 | c11 + 125 | c12 + 136 | c21 + 137 | c22 +(6 rows) + +WITH rcte AS ( SELECT max(id) AS maxid FROM parent ) +DELETE FROM parent USING rcte WHERE id = maxid; +SELECT * FROM parent; + id | val +-----+----- + 114 | p1 + 42 | new + 124 | c11 + 125 | c12 + 136 | c21 +(5 rows) + +WITH wcte AS ( INSERT INTO child2 VALUES ( 42, 'new2' ) RETURNING id AS newid ) +DELETE FROM parent USING wcte WHERE id = newid; +SELECT * FROM parent; + id | val +-----+------ + 114 | p1 + 124 | c11 + 125 | c12 + 136 | c21 + 42 | new2 +(5 rows) + +-- check EXPLAIN VERBOSE for a wCTE with RETURNING +EXPLAIN (VERBOSE, COSTS OFF) +WITH wcte AS ( INSERT INTO int8_tbl VALUES ( 42, 47 ) RETURNING q2 ) +DELETE FROM a_star USING wcte WHERE aa = q2; + QUERY PLAN +--------------------------------------------------------------------------- + Delete on public.a_star + Delete on public.a_star a_star_1 + Delete on public.b_star a_star_2 + Delete on public.c_star a_star_3 + Delete on public.d_star a_star_4 + Delete on public.e_star a_star_5 + Delete on public.f_star a_star_6 + CTE wcte + -> Insert on public.int8_tbl + Output: int8_tbl.q2 + -> Result + Output: '42'::bigint, '47'::bigint + -> Hash Join + Output: wcte.*, a_star.tableoid, a_star.ctid + Hash Cond: (a_star.aa = wcte.q2) + -> Append + -> Seq Scan on public.a_star a_star_1 + Output: a_star_1.aa, a_star_1.tableoid, a_star_1.ctid + -> Seq Scan on public.b_star a_star_2 + Output: a_star_2.aa, a_star_2.tableoid, a_star_2.ctid + -> Seq Scan on public.c_star a_star_3 + Output: a_star_3.aa, a_star_3.tableoid, a_star_3.ctid + -> Seq Scan on public.d_star a_star_4 + Output: a_star_4.aa, a_star_4.tableoid, a_star_4.ctid + -> Seq Scan on public.e_star a_star_5 + Output: a_star_5.aa, a_star_5.tableoid, a_star_5.ctid + -> Seq Scan on public.f_star a_star_6 + Output: a_star_6.aa, a_star_6.tableoid, a_star_6.ctid + -> Hash + Output: wcte.*, wcte.q2 + -> CTE Scan on wcte + Output: wcte.*, wcte.q2 +(32 rows) + +-- error cases +-- data-modifying WITH tries to use its own output +WITH RECURSIVE t AS ( + INSERT INTO y + SELECT * FROM t +) +VALUES(FALSE); +ERROR: recursive query "t" must not contain data-modifying statements +LINE 1: WITH RECURSIVE t AS ( + ^ +-- no RETURNING in a referenced data-modifying WITH +WITH t AS ( + INSERT INTO y VALUES(0) +) +SELECT * FROM t; +ERROR: WITH query "t" does not have a RETURNING clause +LINE 4: SELECT * FROM t; + ^ +-- data-modifying WITH allowed only at the top level +SELECT * FROM ( + WITH t AS (UPDATE y SET a=a+1 RETURNING *) + SELECT * FROM t +) ss; +ERROR: WITH clause containing a data-modifying statement must be at the top level +LINE 2: WITH t AS (UPDATE y SET a=a+1 RETURNING *) + ^ +-- most variants of rules aren't allowed +CREATE RULE y_rule AS ON INSERT TO y WHERE a=0 DO INSTEAD DELETE FROM y; +WITH t AS ( + INSERT INTO y VALUES(0) +) +VALUES(FALSE); +ERROR: conditional DO INSTEAD rules are not supported for data-modifying statements in WITH +CREATE OR REPLACE RULE y_rule AS ON INSERT TO y DO INSTEAD NOTHING; +WITH t AS ( + INSERT INTO y VALUES(0) +) +VALUES(FALSE); +ERROR: DO INSTEAD NOTHING rules are not supported for data-modifying statements in WITH +CREATE OR REPLACE RULE y_rule AS ON INSERT TO y DO INSTEAD NOTIFY foo; +WITH t AS ( + INSERT INTO y VALUES(0) +) +VALUES(FALSE); +ERROR: DO INSTEAD NOTIFY rules are not supported for data-modifying statements in WITH +CREATE OR REPLACE RULE y_rule AS ON INSERT TO y DO ALSO NOTIFY foo; +WITH t AS ( + INSERT INTO y VALUES(0) +) +VALUES(FALSE); +ERROR: DO ALSO rules are not supported for data-modifying statements in WITH +CREATE OR REPLACE RULE y_rule AS ON INSERT TO y + DO INSTEAD (NOTIFY foo; NOTIFY bar); +WITH t AS ( + INSERT INTO y VALUES(0) +) +VALUES(FALSE); +ERROR: multi-statement DO INSTEAD rules are not supported for data-modifying statements in WITH +DROP RULE y_rule ON y; +-- check that parser lookahead for WITH doesn't cause any odd behavior +create table foo (with baz); -- fail, WITH is a reserved word +ERROR: syntax error at or near "with" +LINE 1: create table foo (with baz); + ^ +create table foo (with ordinality); -- fail, WITH is a reserved word +ERROR: syntax error at or near "with" +LINE 1: create table foo (with ordinality); + ^ +with ordinality as (select 1 as x) select * from ordinality; + x +--- + 1 +(1 row) + +-- check sane response to attempt to modify CTE relation +WITH with_test AS (SELECT 42) INSERT INTO with_test VALUES (1); +ERROR: relation "with_test" does not exist +LINE 1: WITH with_test AS (SELECT 42) INSERT INTO with_test VALUES (... + ^ +-- check response to attempt to modify table with same name as a CTE (perhaps +-- surprisingly it works, because CTEs don't hide tables from data-modifying +-- statements) +create temp table with_test (i int); +with with_test as (select 42) insert into with_test select * from with_test; +select * from with_test; + i +---- + 42 +(1 row) + +drop table with_test; |