WL#926 "AVG(DISTINCT) and other distincts", part 2 (out of 3): clean up

Item_sum_count_distinct, and
deploy Unique for use with COUNT(DISTINCT) if there is no blob
column in the list of DISTINCT arguments.


mysql-test/r/count_distinct2.result:
  Test results fixed.
mysql-test/r/func_group.result:
  Updated.
mysql-test/r/sum_distinct.result:
  Updated.
mysql-test/t/func_group.test:
  Add a test for COUNT(DISTINCT) and true varchar and case-insensitive
  collation. The table in the test contains only two distinct values.
mysql-test/t/sum_distinct.test:
  Since now we support INSERT INTO t1 (a) SELECT a+1 FROM t1, shorten
  the test.
  Add a nominal test for AVG(DISTINCT)
sql/item_sum.cc:
  Implementation of cleaned up Item_sum_count_distinct.
  Fixed a bug with COUNT(DISTINCT) and new VARCHAR and collations.
  Fixed a bug wiht AVG(DISTINCT) and wrong number of output digits
  after decimal point.
sql/item_sum.h:
  Cleanup for Item_sum_count_distinct.
  Now if the list of distinct arguments doesn't contain a blob column,
  we always use Unique and merge-sort to find distinct values.
sql/sql_class.h:
  Added a short-cut to find number of elements in Unique if all elements fit
  into memory.

1 files changed, 24 insertions, 58 deletions

diff --git a/mysql-test/t/sum_distinct.test b/mysql-test/t/sum_distinct.test
index 964da9defa6..3b9f12354e8 100644
--- a/mysql-test/t/sum_distinct.test
+++ b/mysql-test/t/sum_distinct.test
@@ -103,64 +103,30 @@ CREATE TABLE t1 (id INTEGER);
 CREATE TABLE t2 (id INTEGER);
 
 INSERT INTO t1 (id) VALUES (1), (1), (1),(1);
-INSERT INTO t2 (id) SELECT id FROM t1;
-INSERT INTO t1 (id) SELECT id FROM t2; /* 8 */
-INSERT INTO t1 (id) SELECT id FROM t2; /* 12 */
-INSERT INTO t1 (id) SELECT id FROM t2; /* 16 */
-INSERT INTO t1 (id) SELECT id FROM t2; /* 20 */
-INSERT INTO t1 (id) SELECT id FROM t2; /* 24 */
-DELETE FROM t2;
-INSERT INTO t2 (id) SELECT id+1 FROM t1;
-INSERT INTO t1 SELECT id FROM t2;
-DELETE FROM t2;
-INSERT INTO t2 (id) SELECT id+2 FROM t1;
-INSERT INTO t1 SELECT id FROM t2;
-DELETE FROM t2;
-INSERT INTO t2 (id) SELECT id+4 FROM t1;
-INSERT INTO t1 SELECT id FROM t2;
-DELETE FROM t2;
-INSERT INTO t2 (id) SELECT id+8 FROM t1;
-INSERT INTO t1 SELECT id FROM t2;
-DELETE FROM t2;
-INSERT INTO t2 (id) SELECT id+16 FROM t1;
-INSERT INTO t1 SELECT id FROM t2;
-DELETE FROM t2;
-INSERT INTO t2 (id) SELECT id+32 FROM t1;
-INSERT INTO t1 SELECT id FROM t2;
-DELETE FROM t2;
-INSERT INTO t2 (id) SELECT id+64 FROM t1;
-INSERT INTO t1 SELECT id FROM t2;
-DELETE FROM t2;
-INSERT INTO t2 (id) SELECT id+128 FROM t1;
-INSERT INTO t1 SELECT id FROM t2;
-DELETE FROM t2;
-INSERT INTO t2 (id) SELECT id+256 FROM t1;
-INSERT INTO t1 SELECT id FROM t2;
-DELETE FROM t2;
-INSERT INTO t2 (id) SELECT id+512 FROM t1;
-INSERT INTO t1 SELECT id FROM t2;
-DELETE FROM t2;
-INSERT INTO t2 (id) SELECT id+1024 FROM t1;
-INSERT INTO t1 SELECT id FROM t2;
-DELETE FROM t2;
-INSERT INTO t2 (id) SELECT id+2048 FROM t1;
-INSERT INTO t1 SELECT id FROM t2;
-DELETE FROM t2;
-INSERT INTO t2 (id) SELECT id+4096 FROM t1;
-INSERT INTO t1 SELECT id FROM t2;
-DELETE FROM t2;
-INSERT INTO t2 (id) SELECT id+8192 FROM t1;
-INSERT INTO t1 SELECT id FROM t2;
-DELETE FROM t2;
-#INSERT INTO t2 (id) SELECT id+16384 FROM t1;
-#INSERT INTO t1 SELECT id FROM t2;
-#DELETE FROM t2;
-#INSERT INTO t2 (id) SELECT id+32768 FROM t1;
-#INSERT INTO t1 SELECT id FROM t2;
-#DELETE FROM t2;
-#INSERT INTO t2 (id) SELECT id+65536 FROM t1;
-#INSERT INTO t1 SELECT id FROM t2;
-#DELETE FROM t2;
+INSERT INTO t1 (id) SELECT id FROM t1; /* 8 */
+INSERT INTO t1 (id) SELECT id FROM t1; /* 12 */
+INSERT INTO t1 (id) SELECT id FROM t1; /* 16 */
+INSERT INTO t1 (id) SELECT id FROM t1; /* 20 */
+INSERT INTO t1 (id) SELECT id FROM t1; /* 24 */
+INSERT INTO t1 SELECT id+1 FROM t1;
+INSERT INTO t1 SELECT id+2 FROM t1;
+INSERT INTO t1 SELECT id+4 FROM t1;
+INSERT INTO t1 SELECT id+8 FROM t1;
+INSERT INTO t1 SELECT id+16 FROM t1;
+INSERT INTO t1 SELECT id+32 FROM t1;
+INSERT INTO t1 SELECT id+64 FROM t1;
+INSERT INTO t1 SELECT id+128 FROM t1;
+INSERT INTO t1 SELECT id+256 FROM t1;
+INSERT INTO t1 SELECT id+512 FROM t1;
+
+# Just test that AVG(DISTINCT) is there
+SELECT AVG(DISTINCT id) FROM t1 GROUP BY id % 13;
+SELECT SUM(DISTINCT id)/COUNT(DISTINCT id) FROM t1 GROUP BY id % 13;
+
+INSERT INTO t1 SELECT id+1024 FROM t1;
+INSERT INTO t1 SELECT id+2048 FROM t1;
+INSERT INTO t1 SELECT id+4096 FROM t1;
+INSERT INTO t1 SELECT id+8192 FROM t1;
 INSERT INTO t2 SELECT id FROM t1 ORDER BY id*rand();
 
 # SELECT '++++++++++++++++++++++++++++++++++++++++++++++++++';