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diff --git a/src/test/regress/sql/tsrf.sql b/src/test/regress/sql/tsrf.sql
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+--
+-- tsrf - targetlist set returning function tests
+--
+
+-- simple srf
+SELECT generate_series(1, 3);
+
+-- parallel iteration
+SELECT generate_series(1, 3), generate_series(3,5);
+
+-- parallel iteration, different number of rows
+SELECT generate_series(1, 2), generate_series(1,4);
+
+-- srf, with SRF argument
+SELECT generate_series(1, generate_series(1, 3));
+
+-- but we've traditionally rejected the same in FROM
+SELECT * FROM generate_series(1, generate_series(1, 3));
+
+-- srf, with two SRF arguments
+SELECT generate_series(generate_series(1,3), generate_series(2, 4));
+
+-- check proper nesting of SRFs in different expressions
+explain (verbose, costs off)
+SELECT generate_series(1, generate_series(1, 3)), generate_series(2, 4);
+SELECT generate_series(1, generate_series(1, 3)), generate_series(2, 4);
+
+CREATE TABLE few(id int, dataa text, datab text);
+INSERT INTO few VALUES(1, 'a', 'foo'),(2, 'a', 'bar'),(3, 'b', 'bar');
+
+-- SRF with a provably-dummy relation
+explain (verbose, costs off)
+SELECT unnest(ARRAY[1, 2]) FROM few WHERE false;
+SELECT unnest(ARRAY[1, 2]) FROM few WHERE false;
+
+-- SRF shouldn't prevent upper query from recognizing lower as dummy
+explain (verbose, costs off)
+SELECT * FROM few f1,
+  (SELECT unnest(ARRAY[1,2]) FROM few f2 WHERE false OFFSET 0) ss;
+SELECT * FROM few f1,
+  (SELECT unnest(ARRAY[1,2]) FROM few f2 WHERE false OFFSET 0) ss;
+
+-- SRF output order of sorting is maintained, if SRF is not referenced
+SELECT few.id, generate_series(1,3) g FROM few ORDER BY id DESC;
+
+-- but SRFs can be referenced in sort
+SELECT few.id, generate_series(1,3) g FROM few ORDER BY id, g DESC;
+SELECT few.id, generate_series(1,3) g FROM few ORDER BY id, generate_series(1,3) DESC;
+
+-- it's weird to have ORDER BYs that increase the number of results
+SELECT few.id FROM few ORDER BY id, generate_series(1,3) DESC;
+
+-- SRFs are computed after aggregation
+SET enable_hashagg TO 0; -- stable output order
+SELECT few.dataa, count(*), min(id), max(id), unnest('{1,1,3}'::int[]) FROM few WHERE few.id = 1 GROUP BY few.dataa;
+-- unless referenced in GROUP BY clause
+SELECT few.dataa, count(*), min(id), max(id), unnest('{1,1,3}'::int[]) FROM few WHERE few.id = 1 GROUP BY few.dataa, unnest('{1,1,3}'::int[]);
+SELECT few.dataa, count(*), min(id), max(id), unnest('{1,1,3}'::int[]) FROM few WHERE few.id = 1 GROUP BY few.dataa, 5;
+RESET enable_hashagg;
+
+-- check HAVING works when GROUP BY does [not] reference SRF output
+SELECT dataa, generate_series(1,1), count(*) FROM few GROUP BY 1 HAVING count(*) > 1;
+SELECT dataa, generate_series(1,1), count(*) FROM few GROUP BY 1, 2 HAVING count(*) > 1;
+
+-- it's weird to have GROUP BYs that increase the number of results
+SELECT few.dataa, count(*) FROM few WHERE dataa = 'a' GROUP BY few.dataa ORDER BY 2;
+SELECT few.dataa, count(*) FROM few WHERE dataa = 'a' GROUP BY few.dataa, unnest('{1,1,3}'::int[]) ORDER BY 2;
+
+-- SRFs are not allowed if they'd need to be conditionally executed
+SELECT q1, case when q1 > 0 then generate_series(1,3) else 0 end FROM int8_tbl;
+SELECT q1, coalesce(generate_series(1,3), 0) FROM int8_tbl;
+
+-- SRFs are not allowed in aggregate arguments
+SELECT min(generate_series(1, 3)) FROM few;
+
+-- ... unless they're within a sub-select
+SELECT sum((3 = ANY(SELECT generate_series(1,4)))::int);
+
+SELECT sum((3 = ANY(SELECT lag(x) over(order by x)
+                    FROM generate_series(1,4) x))::int);
+
+-- SRFs are not allowed in window function arguments, either
+SELECT min(generate_series(1, 3)) OVER() FROM few;
+
+-- SRFs are normally computed after window functions
+SELECT id,lag(id) OVER(), count(*) OVER(), generate_series(1,3) FROM few;
+-- unless referencing SRFs
+SELECT SUM(count(*)) OVER(PARTITION BY generate_series(1,3) ORDER BY generate_series(1,3)), generate_series(1,3) g FROM few GROUP BY g;
+
+-- sorting + grouping
+SELECT few.dataa, count(*), min(id), max(id), generate_series(1,3) FROM few GROUP BY few.dataa ORDER BY 5, 1;
+
+-- grouping sets are a bit special, they produce NULLs in columns not actually NULL
+set enable_hashagg = false;
+SELECT dataa, datab b, generate_series(1,2) g, count(*) FROM few GROUP BY CUBE(dataa, datab);
+SELECT dataa, datab b, generate_series(1,2) g, count(*) FROM few GROUP BY CUBE(dataa, datab) ORDER BY dataa;
+SELECT dataa, datab b, generate_series(1,2) g, count(*) FROM few GROUP BY CUBE(dataa, datab) ORDER BY g;
+SELECT dataa, datab b, generate_series(1,2) g, count(*) FROM few GROUP BY CUBE(dataa, datab, g);
+SELECT dataa, datab b, generate_series(1,2) g, count(*) FROM few GROUP BY CUBE(dataa, datab, g) ORDER BY dataa;
+SELECT dataa, datab b, generate_series(1,2) g, count(*) FROM few GROUP BY CUBE(dataa, datab, g) ORDER BY g;
+reset enable_hashagg;
+
+-- case with degenerate ORDER BY
+explain (verbose, costs off)
+select 'foo' as f, generate_series(1,2) as g from few order by 1;
+select 'foo' as f, generate_series(1,2) as g from few order by 1;
+
+-- data modification
+CREATE TABLE fewmore AS SELECT generate_series(1,3) AS data;
+INSERT INTO fewmore VALUES(generate_series(4,5));
+SELECT * FROM fewmore;
+
+-- SRFs are not allowed in UPDATE (they once were, but it was nonsense)
+UPDATE fewmore SET data = generate_series(4,9);
+
+-- SRFs are not allowed in RETURNING
+INSERT INTO fewmore VALUES(1) RETURNING generate_series(1,3);
+
+-- nor standalone VALUES (but surely this is a bug?)
+VALUES(1, generate_series(1,2));
+
+-- We allow tSRFs that are not at top level
+SELECT int4mul(generate_series(1,2), 10);
+SELECT generate_series(1,3) IS DISTINCT FROM 2;
+
+-- but SRFs in function RTEs must be at top level (annoying restriction)
+SELECT * FROM int4mul(generate_series(1,2), 10);
+
+-- DISTINCT ON is evaluated before tSRF evaluation if SRF is not
+-- referenced either in ORDER BY or in the DISTINCT ON list. The ORDER
+-- BY reference can be implicitly generated, if there's no other ORDER BY.
+
+-- implicit reference (via implicit ORDER) to all columns
+SELECT DISTINCT ON (a) a, b, generate_series(1,3) g
+FROM (VALUES (3, 2), (3,1), (1,1), (1,4), (5,3), (5,1)) AS t(a, b);
+
+-- unreferenced in DISTINCT ON or ORDER BY
+SELECT DISTINCT ON (a) a, b, generate_series(1,3) g
+FROM (VALUES (3, 2), (3,1), (1,1), (1,4), (5,3), (5,1)) AS t(a, b)
+ORDER BY a, b DESC;
+
+-- referenced in ORDER BY
+SELECT DISTINCT ON (a) a, b, generate_series(1,3) g
+FROM (VALUES (3, 2), (3,1), (1,1), (1,4), (5,3), (5,1)) AS t(a, b)
+ORDER BY a, b DESC, g DESC;
+
+-- referenced in ORDER BY and DISTINCT ON
+SELECT DISTINCT ON (a, b, g) a, b, generate_series(1,3) g
+FROM (VALUES (3, 2), (3,1), (1,1), (1,4), (5,3), (5,1)) AS t(a, b)
+ORDER BY a, b DESC, g DESC;
+
+-- only SRF mentioned in DISTINCT ON
+SELECT DISTINCT ON (g) a, b, generate_series(1,3) g
+FROM (VALUES (3, 2), (3,1), (1,1), (1,4), (5,3), (5,1)) AS t(a, b);
+
+-- LIMIT / OFFSET is evaluated after SRF evaluation
+SELECT a, generate_series(1,2) FROM (VALUES(1),(2),(3)) r(a) LIMIT 2 OFFSET 2;
+-- SRFs are not allowed in LIMIT.
+SELECT 1 LIMIT generate_series(1,3);
+
+-- tSRF in correlated subquery, referencing table outside
+SELECT (SELECT generate_series(1,3) LIMIT 1 OFFSET few.id) FROM few;
+-- tSRF in correlated subquery, referencing SRF outside
+SELECT (SELECT generate_series(1,3) LIMIT 1 OFFSET g.i) FROM generate_series(0,3) g(i);
+
+-- Operators can return sets too
+CREATE OPERATOR |@| (PROCEDURE = unnest, RIGHTARG = ANYARRAY);
+SELECT |@|ARRAY[1,2,3];
+
+-- Some fun cases involving duplicate SRF calls
+explain (verbose, costs off)
+select generate_series(1,3) as x, generate_series(1,3) + 1 as xp1;
+select generate_series(1,3) as x, generate_series(1,3) + 1 as xp1;
+explain (verbose, costs off)
+select generate_series(1,3)+1 order by generate_series(1,3);
+select generate_series(1,3)+1 order by generate_series(1,3);
+
+-- Check that SRFs of same nesting level run in lockstep
+explain (verbose, costs off)
+select generate_series(1,3) as x, generate_series(3,6) + 1 as y;
+select generate_series(1,3) as x, generate_series(3,6) + 1 as y;
+
+-- Clean up
+DROP TABLE few;
+DROP TABLE fewmore;