1 files changed, 196 insertions, 0 deletions
diff --git a/src/test/regress/sql/limit.sql b/src/test/regress/sql/limit.sql
new file mode 100644
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+++ b/src/test/regress/sql/limit.sql
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+--
+-- LIMIT
+-- Check the LIMIT/OFFSET feature of SELECT
+--
+
+SELECT ''::text AS two, unique1, unique2, stringu1
+		FROM onek WHERE unique1 > 50
+		ORDER BY unique1 LIMIT 2;
+SELECT ''::text AS five, unique1, unique2, stringu1
+		FROM onek WHERE unique1 > 60
+		ORDER BY unique1 LIMIT 5;
+SELECT ''::text AS two, unique1, unique2, stringu1
+		FROM onek WHERE unique1 > 60 AND unique1 < 63
+		ORDER BY unique1 LIMIT 5;
+SELECT ''::text AS three, unique1, unique2, stringu1
+		FROM onek WHERE unique1 > 100
+		ORDER BY unique1 LIMIT 3 OFFSET 20;
+SELECT ''::text AS zero, unique1, unique2, stringu1
+		FROM onek WHERE unique1 < 50
+		ORDER BY unique1 DESC LIMIT 8 OFFSET 99;
+SELECT ''::text AS eleven, unique1, unique2, stringu1
+		FROM onek WHERE unique1 < 50
+		ORDER BY unique1 DESC LIMIT 20 OFFSET 39;
+SELECT ''::text AS ten, unique1, unique2, stringu1
+		FROM onek
+		ORDER BY unique1 OFFSET 990;
+SELECT ''::text AS five, unique1, unique2, stringu1
+		FROM onek
+		ORDER BY unique1 OFFSET 990 LIMIT 5;
+SELECT ''::text AS five, unique1, unique2, stringu1
+		FROM onek
+		ORDER BY unique1 LIMIT 5 OFFSET 900;
+
+-- Test null limit and offset.  The planner would discard a simple null
+-- constant, so to ensure executor is exercised, do this:
+select * from int8_tbl limit (case when random() < 0.5 then null::bigint end);
+select * from int8_tbl offset (case when random() < 0.5 then null::bigint end);
+
+-- Test assorted cases involving backwards fetch from a LIMIT plan node
+begin;
+
+declare c1 cursor for select * from int8_tbl limit 10;
+fetch all in c1;
+fetch 1 in c1;
+fetch backward 1 in c1;
+fetch backward all in c1;
+fetch backward 1 in c1;
+fetch all in c1;
+
+declare c2 cursor for select * from int8_tbl limit 3;
+fetch all in c2;
+fetch 1 in c2;
+fetch backward 1 in c2;
+fetch backward all in c2;
+fetch backward 1 in c2;
+fetch all in c2;
+
+declare c3 cursor for select * from int8_tbl offset 3;
+fetch all in c3;
+fetch 1 in c3;
+fetch backward 1 in c3;
+fetch backward all in c3;
+fetch backward 1 in c3;
+fetch all in c3;
+
+declare c4 cursor for select * from int8_tbl offset 10;
+fetch all in c4;
+fetch 1 in c4;
+fetch backward 1 in c4;
+fetch backward all in c4;
+fetch backward 1 in c4;
+fetch all in c4;
+
+declare c5 cursor for select * from int8_tbl order by q1 fetch first 2 rows with ties;
+fetch all in c5;
+fetch 1 in c5;
+fetch backward 1 in c5;
+fetch backward 1 in c5;
+fetch all in c5;
+fetch backward all in c5;
+fetch all in c5;
+fetch backward all in c5;
+
+rollback;
+
+-- Stress test for variable LIMIT in conjunction with bounded-heap sorting
+
+SELECT
+  (SELECT n
+     FROM (VALUES (1)) AS x,
+          (SELECT n FROM generate_series(1,10) AS n
+             ORDER BY n LIMIT 1 OFFSET s-1) AS y) AS z
+  FROM generate_series(1,10) AS s;
+
+--
+-- Test behavior of volatile and set-returning functions in conjunction
+-- with ORDER BY and LIMIT.
+--
+
+create temp sequence testseq;
+
+explain (verbose, costs off)
+select unique1, unique2, nextval('testseq')
+  from tenk1 order by unique2 limit 10;
+
+select unique1, unique2, nextval('testseq')
+  from tenk1 order by unique2 limit 10;
+
+select currval('testseq');
+
+explain (verbose, costs off)
+select unique1, unique2, nextval('testseq')
+  from tenk1 order by tenthous limit 10;
+
+select unique1, unique2, nextval('testseq')
+  from tenk1 order by tenthous limit 10;
+
+select currval('testseq');
+
+explain (verbose, costs off)
+select unique1, unique2, generate_series(1,10)
+  from tenk1 order by unique2 limit 7;
+
+select unique1, unique2, generate_series(1,10)
+  from tenk1 order by unique2 limit 7;
+
+explain (verbose, costs off)
+select unique1, unique2, generate_series(1,10)
+  from tenk1 order by tenthous limit 7;
+
+select unique1, unique2, generate_series(1,10)
+  from tenk1 order by tenthous limit 7;
+
+-- use of random() is to keep planner from folding the expressions together
+explain (verbose, costs off)
+select generate_series(0,2) as s1, generate_series((random()*.1)::int,2) as s2;
+
+select generate_series(0,2) as s1, generate_series((random()*.1)::int,2) as s2;
+
+explain (verbose, costs off)
+select generate_series(0,2) as s1, generate_series((random()*.1)::int,2) as s2
+order by s2 desc;
+
+select generate_series(0,2) as s1, generate_series((random()*.1)::int,2) as s2
+order by s2 desc;
+
+-- test for failure to set all aggregates' aggtranstype
+explain (verbose, costs off)
+select sum(tenthous) as s1, sum(tenthous) + random()*0 as s2
+  from tenk1 group by thousand order by thousand limit 3;
+
+select sum(tenthous) as s1, sum(tenthous) + random()*0 as s2
+  from tenk1 group by thousand order by thousand limit 3;
+
+--
+-- FETCH FIRST
+-- Check the WITH TIES clause
+--
+
+SELECT  thousand
+		FROM onek WHERE thousand < 5
+		ORDER BY thousand FETCH FIRST 2 ROW WITH TIES;
+
+SELECT  thousand
+		FROM onek WHERE thousand < 5
+		ORDER BY thousand FETCH FIRST ROWS WITH TIES;
+
+SELECT  thousand
+		FROM onek WHERE thousand < 5
+		ORDER BY thousand FETCH FIRST 1 ROW WITH TIES;
+
+SELECT  thousand
+		FROM onek WHERE thousand < 5
+		ORDER BY thousand FETCH FIRST 2 ROW ONLY;
+
+-- should fail
+SELECT ''::text AS two, unique1, unique2, stringu1
+		FROM onek WHERE unique1 > 50
+		FETCH FIRST 2 ROW WITH TIES;
+
+-- test ruleutils
+CREATE VIEW limit_thousand_v_1 AS SELECT thousand FROM onek WHERE thousand < 995
+		ORDER BY thousand FETCH FIRST 5 ROWS WITH TIES OFFSET 10;
+\d+ limit_thousand_v_1
+CREATE VIEW limit_thousand_v_2 AS SELECT thousand FROM onek WHERE thousand < 995
+		ORDER BY thousand OFFSET 10 FETCH FIRST 5 ROWS ONLY;
+\d+ limit_thousand_v_2
+CREATE VIEW limit_thousand_v_3 AS SELECT thousand FROM onek WHERE thousand < 995
+		ORDER BY thousand FETCH FIRST NULL ROWS WITH TIES;		-- fails
+CREATE VIEW limit_thousand_v_3 AS SELECT thousand FROM onek WHERE thousand < 995
+		ORDER BY thousand FETCH FIRST (NULL+1) ROWS WITH TIES;
+\d+ limit_thousand_v_3
+CREATE VIEW limit_thousand_v_4 AS SELECT thousand FROM onek WHERE thousand < 995
+		ORDER BY thousand FETCH FIRST NULL ROWS ONLY;
+\d+ limit_thousand_v_4
+-- leave these views