1 files changed, 137 insertions, 0 deletions
diff --git a/src/test/regress/sql/select_distinct.sql b/src/test/regress/sql/select_distinct.sql
new file mode 100644
index 0000000..3310274
--- /dev/null
+++ b/src/test/regress/sql/select_distinct.sql
@@ -0,0 +1,137 @@
+--
+-- SELECT_DISTINCT
+--
+
+--
+-- awk '{print $3;}' onek.data | sort -n | uniq
+--
+SELECT DISTINCT two FROM tmp ORDER BY 1;
+
+--
+-- awk '{print $5;}' onek.data | sort -n | uniq
+--
+SELECT DISTINCT ten FROM tmp ORDER BY 1;
+
+--
+-- awk '{print $16;}' onek.data | sort -d | uniq
+--
+SELECT DISTINCT string4 FROM tmp ORDER BY 1;
+
+--
+-- awk '{print $3,$16,$5;}' onek.data | sort -d | uniq |
+-- sort +0n -1 +1d -2 +2n -3
+--
+SELECT DISTINCT two, string4, ten
+   FROM tmp
+   ORDER BY two using <, string4 using <, ten using <;
+
+--
+-- awk '{print $2;}' person.data |
+-- awk '{if(NF!=1){print $2;}else{print;}}' - emp.data |
+-- awk '{if(NF!=1){print $2;}else{print;}}' - student.data |
+-- awk 'BEGIN{FS="      ";}{if(NF!=1){print $5;}else{print;}}' - stud_emp.data |
+-- sort -n -r | uniq
+--
+SELECT DISTINCT p.age FROM person* p ORDER BY age using >;
+
+--
+-- Check mentioning same column more than once
+--
+
+EXPLAIN (VERBOSE, COSTS OFF)
+SELECT count(*) FROM
+  (SELECT DISTINCT two, four, two FROM tenk1) ss;
+
+SELECT count(*) FROM
+  (SELECT DISTINCT two, four, two FROM tenk1) ss;
+
+--
+-- Compare results between plans using sorting and plans using hash
+-- aggregation. Force spilling in both cases by setting work_mem low.
+--
+
+SET work_mem='64kB';
+
+-- Produce results with sorting.
+
+SET enable_hashagg=FALSE;
+
+SET jit_above_cost=0;
+
+EXPLAIN (costs off)
+SELECT DISTINCT g%1000 FROM generate_series(0,9999) g;
+
+CREATE TABLE distinct_group_1 AS
+SELECT DISTINCT g%1000 FROM generate_series(0,9999) g;
+
+SET jit_above_cost TO DEFAULT;
+
+CREATE TABLE distinct_group_2 AS
+SELECT DISTINCT (g%1000)::text FROM generate_series(0,9999) g;
+
+SET enable_hashagg=TRUE;
+
+-- Produce results with hash aggregation.
+
+SET enable_sort=FALSE;
+
+SET jit_above_cost=0;
+
+EXPLAIN (costs off)
+SELECT DISTINCT g%1000 FROM generate_series(0,9999) g;
+
+CREATE TABLE distinct_hash_1 AS
+SELECT DISTINCT g%1000 FROM generate_series(0,9999) g;
+
+SET jit_above_cost TO DEFAULT;
+
+CREATE TABLE distinct_hash_2 AS
+SELECT DISTINCT (g%1000)::text FROM generate_series(0,9999) g;
+
+SET enable_sort=TRUE;
+
+SET work_mem TO DEFAULT;
+
+-- Compare results
+
+(SELECT * FROM distinct_hash_1 EXCEPT SELECT * FROM distinct_group_1)
+  UNION ALL
+(SELECT * FROM distinct_group_1 EXCEPT SELECT * FROM distinct_hash_1);
+
+(SELECT * FROM distinct_hash_1 EXCEPT SELECT * FROM distinct_group_1)
+  UNION ALL
+(SELECT * FROM distinct_group_1 EXCEPT SELECT * FROM distinct_hash_1);
+
+DROP TABLE distinct_hash_1;
+DROP TABLE distinct_hash_2;
+DROP TABLE distinct_group_1;
+DROP TABLE distinct_group_2;
+
+--
+-- Also, some tests of IS DISTINCT FROM, which doesn't quite deserve its
+-- very own regression file.
+--
+
+CREATE TEMP TABLE disttable (f1 integer);
+INSERT INTO DISTTABLE VALUES(1);
+INSERT INTO DISTTABLE VALUES(2);
+INSERT INTO DISTTABLE VALUES(3);
+INSERT INTO DISTTABLE VALUES(NULL);
+
+-- basic cases
+SELECT f1, f1 IS DISTINCT FROM 2 as "not 2" FROM disttable;
+SELECT f1, f1 IS DISTINCT FROM NULL as "not null" FROM disttable;
+SELECT f1, f1 IS DISTINCT FROM f1 as "false" FROM disttable;
+SELECT f1, f1 IS DISTINCT FROM f1+1 as "not null" FROM disttable;
+
+-- check that optimizer constant-folds it properly
+SELECT 1 IS DISTINCT FROM 2 as "yes";
+SELECT 2 IS DISTINCT FROM 2 as "no";
+SELECT 2 IS DISTINCT FROM null as "yes";
+SELECT null IS DISTINCT FROM null as "no";
+
+-- negated form
+SELECT 1 IS NOT DISTINCT FROM 2 as "no";
+SELECT 2 IS NOT DISTINCT FROM 2 as "yes";
+SELECT 2 IS NOT DISTINCT FROM null as "no";
+SELECT null IS NOT DISTINCT FROM null as "yes";