bug #27531: 5.1 part of the fix:

 - added join cache indication in EXPLAIN (Extra column).
 - prefer filesort over full scan over 
   index for ORDER BY (because it's faster).
 - when switching from REF to RANGE because
   RANGE uses longer key turn off sort on
   the head table only as the resulting 
   RANGE access is a candidate for join cache
   and we don't want to disable it by sorting
   on the first table only. 
parent 19b9c7a8
......@@ -402,7 +402,7 @@ Equals(g1.g, g2.g) as e, Disjoint(g1.g, g2.g) as d, Touches(g1.g, g2.g) as t,
Intersects(g1.g, g2.g) as i, Crosses(g1.g, g2.g) as r
FROM gis_geometrycollection g1, gis_geometrycollection g2 ORDER BY first, second;
id select_type table type possible_keys key key_len ref rows filtered Extra
1 SIMPLE g1 ALL NULL NULL NULL NULL 2 100.00 Using temporary; Using filesort
1 SIMPLE g1 ALL NULL NULL NULL NULL 2 100.00 Using temporary; Using filesort; Using join cache
1 SIMPLE g2 ALL NULL NULL NULL NULL 2 100.00
Warnings:
Note 1003 select `test`.`g1`.`fid` AS `first`,`test`.`g2`.`fid` AS `second`,within(`test`.`g1`.`g`,`test`.`g2`.`g`) AS `w`,contains(`test`.`g1`.`g`,`test`.`g2`.`g`) AS `c`,overlaps(`test`.`g1`.`g`,`test`.`g2`.`g`) AS `o`,equals(`test`.`g1`.`g`,`test`.`g2`.`g`) AS `e`,disjoint(`test`.`g1`.`g`,`test`.`g2`.`g`) AS `d`,touches(`test`.`g1`.`g`,`test`.`g2`.`g`) AS `t`,intersects(`test`.`g1`.`g`,`test`.`g2`.`g`) AS `i`,crosses(`test`.`g1`.`g`,`test`.`g2`.`g`) AS `r` from `test`.`gis_geometrycollection` `g1` join `test`.`gis_geometrycollection` `g2` order by `test`.`g1`.`fid`,`test`.`g2`.`fid`
......
......@@ -611,11 +611,11 @@ id select_type table type possible_keys key key_len ref rows Extra
1 SIMPLE t3 ref period period 4 test.t1.period 4181
explain select * from t3 as t1,t3 where t1.period=t3.period order by t3.period limit 10;
id select_type table type possible_keys key key_len ref rows Extra
1 SIMPLE t3 index period period 4 NULL 41810
1 SIMPLE t3 ALL period NULL NULL NULL 41810 Using filesort
1 SIMPLE t1 ref period period 4 test.t3.period 4181
explain select * from t3 as t1,t3 where t1.period=t3.period order by t1.period limit 10;
id select_type table type possible_keys key key_len ref rows Extra
1 SIMPLE t1 index period period 4 NULL 41810
1 SIMPLE t1 ALL period NULL NULL NULL 41810 Using filesort
1 SIMPLE t3 ref period period 4 test.t1.period 4181
select period from t1;
period
......@@ -1434,7 +1434,7 @@ companynr companynr
41 40
explain select distinct t2.companynr,t4.companynr from t2,t4 where t2.companynr=t4.companynr+1;
id select_type table type possible_keys key key_len ref rows Extra
1 SIMPLE t4 index NULL PRIMARY 1 NULL 12 Using index; Using temporary
1 SIMPLE t4 index NULL PRIMARY 1 NULL 12 Using index; Using temporary; Using join cache
1 SIMPLE t2 ALL NULL NULL NULL NULL 1199 Using where
select t2.fld1,t2.companynr,fld3,period from t3,t2 where t2.fld1 = 38208 and t2.fld1=t3.t2nr and period = 1008 or t2.fld1 = 38008 and t2.fld1 =t3.t2nr and period = 1008;
fld1 companynr fld3 period
......
......@@ -1454,7 +1454,7 @@ insert into t1 values ('123'), ('456');
explain
select substr(Z.a,-1), Z.a from t1 as Y join t1 as Z on Y.a=Z.a order by 1;
id select_type table type possible_keys key key_len ref rows Extra
1 SIMPLE Y ALL NULL NULL NULL NULL 2 Using temporary; Using filesort
1 SIMPLE Y ALL NULL NULL NULL NULL 2 Using temporary; Using filesort; Using join cache
1 SIMPLE Z ALL NULL NULL NULL NULL 2 Using where
select substr(Z.a,-1), Z.a from t1 as Y join t1 as Z on Y.a=Z.a order by 1;
substr(Z.a,-1) a
......
......@@ -57,7 +57,7 @@ a b a b
3 c 3 c
explain select * from t1 as x1, (select * from t1) as x2;
id select_type table type possible_keys key key_len ref rows Extra
1 PRIMARY x1 ALL NULL NULL NULL NULL 4
1 PRIMARY x1 ALL NULL NULL NULL NULL 4 Using join cache
1 PRIMARY <derived2> ALL NULL NULL NULL NULL 4
2 DERIVED t1 ALL NULL NULL NULL NULL 4
drop table if exists t2,t3;
......@@ -188,13 +188,13 @@ pla_id test
105 3
explain SELECT STRAIGHT_JOIN d.pla_id, m2.mat_id FROM t1 m2 INNER JOIN (SELECT mp.pla_id, MIN(m1.matintnum) AS matintnum FROM t2 mp INNER JOIN t1 m1 ON mp.mat_id=m1.mat_id GROUP BY mp.pla_id) d ON d.matintnum=m2.matintnum;
id select_type table type possible_keys key key_len ref rows Extra
1 PRIMARY m2 ALL NULL NULL NULL NULL 9
1 PRIMARY m2 ALL NULL NULL NULL NULL 9 Using join cache
1 PRIMARY <derived2> ALL NULL NULL NULL NULL 6 Using where
2 DERIVED mp ALL NULL NULL NULL NULL 9 Using temporary; Using filesort
2 DERIVED m1 eq_ref PRIMARY PRIMARY 3 test.mp.mat_id 1
explain SELECT STRAIGHT_JOIN d.pla_id, m2.test FROM t1 m2 INNER JOIN (SELECT mp.pla_id, MIN(m1.matintnum) AS matintnum FROM t2 mp INNER JOIN t1 m1 ON mp.mat_id=m1.mat_id GROUP BY mp.pla_id) d ON d.matintnum=m2.matintnum;
id select_type table type possible_keys key key_len ref rows Extra
1 PRIMARY m2 ALL NULL NULL NULL NULL 9
1 PRIMARY m2 ALL NULL NULL NULL NULL 9 Using join cache
1 PRIMARY <derived2> ALL NULL NULL NULL NULL 6 Using where
2 DERIVED mp ALL NULL NULL NULL NULL 9 Using temporary; Using filesort
2 DERIVED m1 eq_ref PRIMARY PRIMARY 3 test.mp.mat_id 1
......@@ -245,7 +245,7 @@ a a
2 2
explain select * from ( select * from t1 union select * from t1) a,(select * from t1 union select * from t1) b;
id select_type table type possible_keys key key_len ref rows Extra
1 PRIMARY <derived2> ALL NULL NULL NULL NULL 2
1 PRIMARY <derived2> ALL NULL NULL NULL NULL 2 Using join cache
1 PRIMARY <derived4> ALL NULL NULL NULL NULL 2
4 DERIVED t1 ALL NULL NULL NULL NULL 2
5 UNION t1 ALL NULL NULL NULL NULL 2
......@@ -312,7 +312,7 @@ b 3.5000
explain SELECT s.name, AVG(s.val) AS median FROM (SELECT x.name, x.val FROM t1 x, t1 y WHERE x.name=y.name GROUP BY x.name, x.val HAVING SUM(y.val <= x.val) >= COUNT(*)/2 AND SUM(y.val >= x.val) >= COUNT(*)/2) AS s GROUP BY s.name;
id select_type table type possible_keys key key_len ref rows Extra
1 PRIMARY <derived2> ALL NULL NULL NULL NULL 3 Using temporary; Using filesort
2 DERIVED x ALL NULL NULL NULL NULL 17 Using temporary; Using filesort
2 DERIVED x ALL NULL NULL NULL NULL 17 Using temporary; Using filesort; Using join cache
2 DERIVED y ALL NULL NULL NULL NULL 17 Using where
drop table t1;
create table t2 (a int, b int, primary key (a));
......
......@@ -174,7 +174,7 @@ INSERT INTO t3 VALUES (1,'1'),(2,'2'),(1,'1'),(2,'2');
explain SELECT distinct t3.a FROM t3,t2,t1 WHERE t3.a=t1.b AND t1.a=t2.a;
id select_type table type possible_keys key key_len ref rows Extra
1 SIMPLE t1 ALL PRIMARY NULL NULL NULL 4 Using temporary
1 SIMPLE t3 ref a a 5 test.t1.b 2 Using where; Using index
1 SIMPLE t3 ref a a 5 test.t1.b 2 Using where; Using index; Using join cache
1 SIMPLE t2 index a a 4 NULL 5 Using where; Using index; Distinct
SELECT distinct t3.a FROM t3,t2,t1 WHERE t3.a=t1.b AND t1.a=t2.a;
a
......@@ -299,11 +299,11 @@ WHERE
((t1.id=j_lj_t2.id AND t2_lj.id IS NULL) OR (t1.id=t2.id AND t2.idx=2))
AND ((t1.id=j_lj_t3.id AND t3_lj.id IS NULL) OR (t1.id=t3.id AND t3.idx=2));
id select_type table type possible_keys key key_len ref rows Extra
1 SIMPLE t1 index id id 4 NULL 2 Using index; Using temporary
1 SIMPLE t2 index id id 8 NULL 1 Using index; Distinct
1 SIMPLE t3 index id id 8 NULL 1 Using index; Distinct
1 SIMPLE t1 index id id 4 NULL 2 Using index; Using temporary; Using join cache
1 SIMPLE t2 index id id 8 NULL 1 Using index; Distinct; Using join cache
1 SIMPLE t3 index id id 8 NULL 1 Using index; Distinct; Using join cache
1 SIMPLE j_lj_t2 index id id 4 NULL 2 Using where; Using index; Distinct
1 SIMPLE t2_lj ref id id 4 test.j_lj_t2.id 1 Using where; Using index; Distinct
1 SIMPLE t2_lj ref id id 4 test.j_lj_t2.id 1 Using where; Using index; Distinct; Using join cache
1 SIMPLE j_lj_t3 index id id 4 NULL 2 Using where; Using index; Distinct
1 SIMPLE t3_lj ref id id 4 test.j_lj_t3.id 1 Using where; Using index; Distinct
SELECT DISTINCT
......@@ -514,7 +514,7 @@ id select_type table type possible_keys key key_len ref rows Extra
1 SIMPLE t1 ALL NULL NULL NULL NULL 3
EXPLAIN SELECT DISTINCT t1_1.a, t1_1.b FROM t1 t1_1, t1 t1_2;
id select_type table type possible_keys key key_len ref rows Extra
1 SIMPLE t1_1 ALL NULL NULL NULL NULL 3 Using temporary
1 SIMPLE t1_1 ALL NULL NULL NULL NULL 3 Using temporary; Using join cache
1 SIMPLE t1_2 index NULL PRIMARY 4 NULL 3 Using index; Distinct
EXPLAIN SELECT DISTINCT t1_1.a, t1_1.b FROM t1 t1_1, t1 t1_2
WHERE t1_1.a = t1_2.a;
......
......@@ -613,7 +613,7 @@ id select_type table type possible_keys key key_len ref rows Extra
explain
select max(t1.a3), min(t2.a2) from t1, t2 where t1.a2 = 2 and t1.a3 < 'MIN' and t2.a3 > 'CA';
id select_type table type possible_keys key key_len ref rows Extra
1 SIMPLE t1 range k1 k1 7 NULL 1 Using where; Using index
1 SIMPLE t1 range k1 k1 7 NULL 1 Using where; Using index; Using join cache
1 SIMPLE t2 range k1 k1 3 NULL 4 Using where; Using index
explain
select min(a4 - 0.01) from t1;
......@@ -650,7 +650,7 @@ id select_type table type possible_keys key key_len ref rows Extra
explain
select concat(min(t1.a1),min(t2.a4)) from t1, t2 where t2.a4 <> 'AME';
id select_type table type possible_keys key key_len ref rows Extra
1 SIMPLE t2 range k2 k2 4 NULL 6 Using where; Using index
1 SIMPLE t2 range k2 k2 4 NULL 6 Using where; Using index; Using join cache
1 SIMPLE t1 index NULL PRIMARY 3 NULL 15 Using index
drop table t1, t2;
create table t1 (a char(10));
......
......@@ -78,7 +78,7 @@ min(7)
7
explain select min(7) from t2i join t1i;
id select_type table type possible_keys key key_len ref rows Extra
1 SIMPLE t2i ALL NULL NULL NULL NULL 1
1 SIMPLE t2i ALL NULL NULL NULL NULL 1 Using join cache
1 SIMPLE t1i ALL NULL NULL NULL NULL 1
select min(7) from t2i join t1i;
min(7)
......@@ -94,7 +94,7 @@ max(7)
7
explain select max(7) from t2i join t1i;
id select_type table type possible_keys key key_len ref rows Extra
1 SIMPLE t2i ALL NULL NULL NULL NULL 1
1 SIMPLE t2i ALL NULL NULL NULL NULL 1 Using join cache
1 SIMPLE t1i ALL NULL NULL NULL NULL 1
select max(7) from t2i join t1i;
max(7)
......
......@@ -394,7 +394,7 @@ Equals(g1.g, g2.g) as e, Disjoint(g1.g, g2.g) as d, Touches(g1.g, g2.g) as t,
Intersects(g1.g, g2.g) as i, Crosses(g1.g, g2.g) as r
FROM gis_geometrycollection g1, gis_geometrycollection g2 ORDER BY first, second;
id select_type table type possible_keys key key_len ref rows filtered Extra
1 SIMPLE g1 ALL NULL NULL NULL NULL 2 100.00 Using temporary; Using filesort
1 SIMPLE g1 ALL NULL NULL NULL NULL 2 100.00 Using temporary; Using filesort; Using join cache
1 SIMPLE g2 ALL NULL NULL NULL NULL 2 100.00
Warnings:
Note 1003 select `test`.`g1`.`fid` AS `first`,`test`.`g2`.`fid` AS `second`,within(`test`.`g1`.`g`,`test`.`g2`.`g`) AS `w`,contains(`test`.`g1`.`g`,`test`.`g2`.`g`) AS `c`,overlaps(`test`.`g1`.`g`,`test`.`g2`.`g`) AS `o`,equals(`test`.`g1`.`g`,`test`.`g2`.`g`) AS `e`,disjoint(`test`.`g1`.`g`,`test`.`g2`.`g`) AS `d`,touches(`test`.`g1`.`g`,`test`.`g2`.`g`) AS `t`,intersects(`test`.`g1`.`g`,`test`.`g2`.`g`) AS `i`,crosses(`test`.`g1`.`g`,`test`.`g2`.`g`) AS `r` from `test`.`gis_geometrycollection` `g1` join `test`.`gis_geometrycollection` `g2` order by `test`.`g1`.`fid`,`test`.`g2`.`fid`
......
This diff is collapsed.
......@@ -536,11 +536,11 @@ a b
1 1
explain select t1.a,t2.b from t1,t2 where t1.a=t2.a group by t1.a,t2.b;
id select_type table type possible_keys key key_len ref rows Extra
1 SIMPLE t1 ALL NULL NULL NULL NULL 6 Using temporary; Using filesort
1 SIMPLE t1 ALL NULL NULL NULL NULL 6 Using temporary; Using filesort; Using join cache
1 SIMPLE t2 ALL a NULL NULL NULL 4 Using where
explain select t1.a,t2.b from t1,t2 where t1.a=t2.a group by t1.a,t2.b ORDER BY NULL;
id select_type table type possible_keys key key_len ref rows Extra
1 SIMPLE t1 ALL NULL NULL NULL NULL 6 Using temporary
1 SIMPLE t1 ALL NULL NULL NULL NULL 6 Using temporary; Using join cache
1 SIMPLE t2 ALL a NULL NULL NULL 4 Using where
drop table t1,t2;
create table t1 (a int, b int);
......
......@@ -2266,7 +2266,7 @@ EXPLAIN SELECT 1 FROM t1 AS t1_outer1 JOIN t1 AS t1_outer2
ON t1_outer1.a = (SELECT max(b) FROM t1 GROUP BY a HAVING a < 2)
AND t1_outer1.b = t1_outer2.b;
id select_type table type possible_keys key key_len ref rows Extra
1 PRIMARY t1_outer1 ref a a 5 const 1 Using where; Using index
1 PRIMARY t1_outer1 ref a a 5 const 1 Using where; Using index; Using join cache
1 PRIMARY t1_outer2 index NULL a 10 NULL 15 Using where; Using index
2 SUBQUERY t1 range NULL a 5 NULL 8 Using index for group-by
EXPLAIN SELECT (SELECT (SELECT max(b) FROM t1 GROUP BY a HAVING a < 2) x
......
......@@ -270,7 +270,7 @@ id select_type table type possible_keys key key_len ref rows Extra
explain select * from t0,t1 where t0.key1 = 5 and
(t1.key1 = t0.key1 or t1.key8 = t0.key1);
id select_type table type possible_keys key key_len ref rows Extra
1 SIMPLE t0 ref i1 i1 4 const 1
1 SIMPLE t0 ref i1 i1 4 const 1 Using join cache
1 SIMPLE t1 index_merge i1,i8 i1,i8 4,4 NULL 2 Using union(i1,i8); Using where
explain select * from t0,t1 where t0.key1 < 3 and
(t1.key1 = t0.key1 or t1.key8 = t0.key1);
......@@ -347,7 +347,7 @@ from t0 as A force index(i1,i2), t0 as B force index (i1,i2)
where (A.key1 < 500000 or A.key2 < 3)
and (B.key1 < 500000 or B.key2 < 3);
id select_type table type possible_keys key key_len ref rows Extra
1 SIMPLE A index_merge i1,i2 i1,i2 4,4 NULL 1013 Using sort_union(i1,i2); Using where
1 SIMPLE A index_merge i1,i2 i1,i2 4,4 NULL 1013 Using sort_union(i1,i2); Using where; Using join cache
1 SIMPLE B index_merge i1,i2 i1,i2 4,4 NULL 1013 Using sort_union(i1,i2); Using where
select max(A.key1 + B.key1 + A.key2 + B.key2 + A.key3 + B.key3 + A.key4 + B.key4 + A.key5 + B.key5)
from t0 as A force index(i1,i2), t0 as B force index (i1,i2)
......@@ -361,7 +361,7 @@ from t0 as A force index(i1,i2), t0 as B force index (i1,i2)
where (A.key1 = 1 or A.key2 = 1)
and (B.key1 = 1 or B.key2 = 1);
id select_type table type possible_keys key key_len ref rows Extra
1 SIMPLE A index_merge i1,i2 i1,i2 4,4 NULL 1020 Using union(i1,i2); Using where
1 SIMPLE A index_merge i1,i2 i1,i2 4,4 NULL 1020 Using union(i1,i2); Using where; Using join cache
1 SIMPLE B index_merge i1,i2 i1,i2 4,4 NULL 1020 Using union(i1,i2); Using where
select max(A.key1 + B.key1 + A.key2 + B.key2 + A.key3 + B.key3 + A.key4 + B.key4 + A.key5 + B.key5)
from t0 as A force index(i1,i2), t0 as B force index (i1,i2)
......@@ -376,7 +376,7 @@ from t0 as A, t0 as B
where (A.key1 = 1 and A.key2 = 1 and A.key3 = 1 and A.key4=1 and A.key5=1 and A.key6=1 and A.key7 = 1 or A.key8=1)
and (B.key1 = 1 and B.key2 = 1 and B.key3 = 1 and B.key4=1 and B.key5=1 and B.key6=1 and B.key7 = 1 or B.key8=1);
id select_type table type possible_keys key key_len ref rows Extra
1 SIMPLE A index_merge i1,i2,i3,i4,i5,i6,i7?,i8 i2,i3,i4,i5,i6,i7?,i8 X NULL # Using union(intersect(i2,i3,i4,i5,i6,i7?),i8); Using where
1 SIMPLE A index_merge i1,i2,i3,i4,i5,i6,i7?,i8 i2,i3,i4,i5,i6,i7?,i8 X NULL # Using union(intersect(i2,i3,i4,i5,i6,i7?),i8); Using where; Using join cache
1 SIMPLE B index_merge i1,i2,i3,i4,i5,i6,i7?,i8 i2,i3,i4,i5,i6,i7?,i8 X NULL # Using union(intersect(i2,i3,i4,i5,i6,i7?),i8); Using where
select max(A.key1 + B.key1 + A.key2 + B.key2 + A.key3 + B.key3 + A.key4 + B.key4 + A.key5 + B.key5)
from t0 as A, t0 as B
......
......@@ -289,7 +289,7 @@ explain select a.ROUTINE_NAME from information_schema.ROUTINES a,
information_schema.SCHEMATA b where
a.ROUTINE_SCHEMA = b.SCHEMA_NAME;
id select_type table type possible_keys key key_len ref rows Extra
1 SIMPLE # ALL NULL NULL NULL NULL 2
1 SIMPLE # ALL NULL NULL NULL NULL 2 Using join cache
1 SIMPLE # ALL NULL NULL NULL NULL 2 Using where
select a.ROUTINE_NAME, b.name from information_schema.ROUTINES a,
mysql.proc b where a.ROUTINE_NAME = convert(b.name using utf8) order by 1;
......
......@@ -402,7 +402,7 @@ Equals(g1.g, g2.g) as e, Disjoint(g1.g, g2.g) as d, Touches(g1.g, g2.g) as t,
Intersects(g1.g, g2.g) as i, Crosses(g1.g, g2.g) as r
FROM gis_geometrycollection g1, gis_geometrycollection g2 ORDER BY first, second;
id select_type table type possible_keys key key_len ref rows filtered Extra
1 SIMPLE g1 ALL NULL NULL NULL NULL 2 100.00 Using temporary; Using filesort
1 SIMPLE g1 ALL NULL NULL NULL NULL 2 100.00 Using temporary; Using filesort; Using join cache
1 SIMPLE g2 ALL NULL NULL NULL NULL 2 100.00
Warnings:
Note 1003 select `test`.`g1`.`fid` AS `first`,`test`.`g2`.`fid` AS `second`,within(`test`.`g1`.`g`,`test`.`g2`.`g`) AS `w`,contains(`test`.`g1`.`g`,`test`.`g2`.`g`) AS `c`,overlaps(`test`.`g1`.`g`,`test`.`g2`.`g`) AS `o`,equals(`test`.`g1`.`g`,`test`.`g2`.`g`) AS `e`,disjoint(`test`.`g1`.`g`,`test`.`g2`.`g`) AS `d`,touches(`test`.`g1`.`g`,`test`.`g2`.`g`) AS `t`,intersects(`test`.`g1`.`g`,`test`.`g2`.`g`) AS `i`,crosses(`test`.`g1`.`g`,`test`.`g2`.`g`) AS `r` from `test`.`gis_geometrycollection` `g1` join `test`.`gis_geometrycollection` `g2` order by `test`.`g1`.`fid`,`test`.`g2`.`fid`
......
......@@ -163,7 +163,7 @@ min(7)
7
explain select min(7) from t2i join t1i;
id select_type table type possible_keys key key_len ref rows Extra
1 SIMPLE t2i ALL NULL NULL NULL NULL 1
1 SIMPLE t2i ALL NULL NULL NULL NULL 1 Using join cache
1 SIMPLE t1i ALL NULL NULL NULL NULL 1
select min(7) from t2i join t1i;
min(7)
......@@ -179,7 +179,7 @@ max(7)
7
explain select max(7) from t2i join t1i;
id select_type table type possible_keys key key_len ref rows Extra
1 SIMPLE t2i ALL NULL NULL NULL NULL 1
1 SIMPLE t2i ALL NULL NULL NULL NULL 1 Using join cache
1 SIMPLE t1i ALL NULL NULL NULL NULL 1
select max(7) from t2i join t1i;
max(7)
......
......@@ -403,7 +403,7 @@ EXPLAIN
SELECT STRAIGHT_JOIN t2.e FROM t1,t2 WHERE t2.d=1 AND t1.b=t2.e
ORDER BY t1.b, t1.c;
id select_type table type possible_keys key key_len ref rows Extra
1 SIMPLE t1 ALL NULL NULL NULL NULL 32 Using temporary; Using filesort
1 SIMPLE t1 ALL NULL NULL NULL NULL 32 Using temporary; Using filesort; Using join cache
1 SIMPLE t2 ALL NULL NULL NULL NULL 16 Using where
SELECT STRAIGHT_JOIN t2.e FROM t1,t2 WHERE t2.d=1 AND t1.b=t2.e
ORDER BY t1.b, t1.c;
......
This diff is collapsed.
......@@ -35,7 +35,7 @@ D E a a
a a a a
explain select t1.*,t2.* from t1,t1 as t2 where t1.A=t2.B;
id select_type table type possible_keys key key_len ref rows Extra
1 SIMPLE t1 ALL a NULL NULL NULL 5
1 SIMPLE t1 ALL a NULL NULL NULL 5 Using join cache
1 SIMPLE t2 ALL b NULL NULL NULL 5 Using where
select t1.*,t2.* from t1,t1 as t2 where t1.A=t2.B order by binary t1.a,t2.a;
a b a b
......
......@@ -345,11 +345,11 @@ t1 1 c_2 1 c A 5 NULL NULL YES BTREE
t1 1 c_2 2 a A 5 NULL NULL BTREE
explain select * from t1,t2 where t1.a=t2.a;
id select_type table type possible_keys key key_len ref rows Extra
1 SIMPLE t2 ALL a NULL NULL NULL 2
1 SIMPLE t2 ALL a NULL NULL NULL 2 Using join cache
1 SIMPLE t1 ALL a NULL NULL NULL 5 Using where
explain select * from t1,t2 force index(a) where t1.a=t2.a;
id select_type table type possible_keys key key_len ref rows Extra
1 SIMPLE t2 ALL a NULL NULL NULL 2
1 SIMPLE t2 ALL a NULL NULL NULL 2 Using join cache
1 SIMPLE t1 ALL a NULL NULL NULL 5 Using where
explain select * from t1 force index(a),t2 force index(a) where t1.a=t2.a;
id select_type table type possible_keys key key_len ref rows Extra
......@@ -361,7 +361,7 @@ id select_type table type possible_keys key key_len ref rows Extra
1 SIMPLE t1 ref b b 5 test.t2.b 1 Using where
explain select * from t1,t2 force index(c) where t1.a=t2.a;
id select_type table type possible_keys key key_len ref rows Extra
1 SIMPLE t2 ALL NULL NULL NULL NULL 2
1 SIMPLE t2 ALL NULL NULL NULL NULL 2 Using join cache
1 SIMPLE t1 ALL a NULL NULL NULL 5 Using where
explain select * from t1 where a=0 or a=2;
id select_type table type possible_keys key key_len ref rows Extra
......
......@@ -1730,7 +1730,7 @@ pk1 attr1 attr2 attr3 attr4
explain
select * from t2,t3 where t2.attr1 < 1 and t2.attr2 = t3.attr2 and t3.attr1 < 5 order by t2.pk1;
id select_type table type possible_keys key key_len ref rows Extra
1 SIMPLE t2 ALL NULL NULL NULL NULL # Using where with pushed condition; Using temporary; Using filesort
1 SIMPLE t2 ALL NULL NULL NULL NULL # Using where with pushed condition; Using temporary; Using filesort; Using join cache
1 SIMPLE t3 ALL NULL NULL NULL NULL # Using where with pushed condition
select * from t2,t3 where t2.attr1 < 1 and t2.attr2 = t3.attr2 and t3.attr1 < 5 order by t2.pk1;
pk1 attr1 attr2 attr3 pk1 attr1 attr2 attr3 attr4
......@@ -1746,7 +1746,7 @@ pk1 attr1 attr2 attr3 attr4
explain
select * from t3,t4 where t4.attr1 > 1 and t4.attr2 = t3.attr2 and t4.attr3 < 5 order by t4.pk1;
id select_type table type possible_keys key key_len ref rows Extra
1 SIMPLE t4 range attr1 attr1 4 NULL # Using where with pushed condition; Using temporary; Using filesort
1 SIMPLE t4 range attr1 attr1 4 NULL # Using where with pushed condition; Using temporary; Using filesort; Using join cache
1 SIMPLE t3 ALL NULL NULL NULL NULL # Using where
select * from t3,t4 where t4.attr1 > 1 and t4.attr2 = t3.attr2 and t4.attr3 < 5 order by t4.pk1;
pk1 attr1 attr2 attr3 attr4 pk1 attr1 attr2 attr3 attr4
......
......@@ -402,7 +402,7 @@ Equals(g1.g, g2.g) as e, Disjoint(g1.g, g2.g) as d, Touches(g1.g, g2.g) as t,
Intersects(g1.g, g2.g) as i, Crosses(g1.g, g2.g) as r
FROM gis_geometrycollection g1, gis_geometrycollection g2 ORDER BY first, second;
id select_type table type possible_keys key key_len ref rows filtered Extra
1 SIMPLE g1 ALL NULL NULL NULL NULL 2 100.00 Using temporary; Using filesort
1 SIMPLE g1 ALL NULL NULL NULL NULL 2 100.00 Using temporary; Using filesort; Using join cache
1 SIMPLE g2 ALL NULL NULL NULL NULL 2 100.00
Warnings:
Note 1003 select `test`.`g1`.`fid` AS `first`,`test`.`g2`.`fid` AS `second`,within(`test`.`g1`.`g`,`test`.`g2`.`g`) AS `w`,contains(`test`.`g1`.`g`,`test`.`g2`.`g`) AS `c`,overlaps(`test`.`g1`.`g`,`test`.`g2`.`g`) AS `o`,equals(`test`.`g1`.`g`,`test`.`g2`.`g`) AS `e`,disjoint(`test`.`g1`.`g`,`test`.`g2`.`g`) AS `d`,touches(`test`.`g1`.`g`,`test`.`g2`.`g`) AS `t`,intersects(`test`.`g1`.`g`,`test`.`g2`.`g`) AS `i`,crosses(`test`.`g1`.`g`,`test`.`g2`.`g`) AS `r` from `test`.`gis_geometrycollection` `g1` join `test`.`gis_geometrycollection` `g2` order by `test`.`g1`.`fid`,`test`.`g2`.`fid`
......@@ -952,7 +952,7 @@ Equals(g1.g, g2.g) as e, Disjoint(g1.g, g2.g) as d, Touches(g1.g, g2.g) as t,
Intersects(g1.g, g2.g) as i, Crosses(g1.g, g2.g) as r
FROM gis_geometrycollection g1, gis_geometrycollection g2 ORDER BY first, second;
id select_type table type possible_keys key key_len ref rows filtered Extra
1 SIMPLE g1 ALL NULL NULL NULL NULL 2 100.00 Using temporary; Using filesort
1 SIMPLE g1 ALL NULL NULL NULL NULL 2 100.00 Using temporary; Using filesort; Using join cache
1 SIMPLE g2 ALL NULL NULL NULL NULL 2 100.00
Warnings:
Note 1003 select `test`.`g1`.`fid` AS `first`,`test`.`g2`.`fid` AS `second`,within(`test`.`g1`.`g`,`test`.`g2`.`g`) AS `w`,contains(`test`.`g1`.`g`,`test`.`g2`.`g`) AS `c`,overlaps(`test`.`g1`.`g`,`test`.`g2`.`g`) AS `o`,equals(`test`.`g1`.`g`,`test`.`g2`.`g`) AS `e`,disjoint(`test`.`g1`.`g`,`test`.`g2`.`g`) AS `d`,touches(`test`.`g1`.`g`,`test`.`g2`.`g`) AS `t`,intersects(`test`.`g1`.`g`,`test`.`g2`.`g`) AS `i`,crosses(`test`.`g1`.`g`,`test`.`g2`.`g`) AS `r` from `test`.`gis_geometrycollection` `g1` join `test`.`gis_geometrycollection` `g2` order by `test`.`g1`.`fid`,`test`.`g2`.`fid`
......
......@@ -220,27 +220,27 @@ insert into t1 (x) values (1),(2),(3),(4),(5),(6),(7),(8),(9);
update t1 set y=x;
explain select * from t1, t1 t2 where t1.y = 8 and t2.x between 7 and t1.y+0;
id select_type table type possible_keys key key_len ref rows Extra
1 SIMPLE t1 ref y y 5 const 1 Using where
1 SIMPLE t1 ref y y 5 const 1 Using where; Using join cache
1 SIMPLE t2 range x x 5 NULL 2 Using where
explain select * from t1, t1 t2 where t1.y = 8 and t2.x >= 7 and t2.x <= t1.y+0;
id select_type table type possible_keys key key_len ref rows Extra
1 SIMPLE t1 ref y y 5 const 1 Using where
1 SIMPLE t1 ref y y 5 const 1 Using where; Using join cache
1 SIMPLE t2 range x x 5 NULL 2 Using where
explain select * from t1, t1 t2 where t1.y = 2 and t2.x between t1.y-1 and t1.y+1;
id select_type table type possible_keys key key_len ref rows Extra
1 SIMPLE t1 ref y y 5 const 1 Using where
1 SIMPLE t1 ref y y 5 const 1 Using where; Using join cache
1 SIMPLE t2 range x x 5 NULL 3 Using where
explain select * from t1, t1 t2 where t1.y = 2 and t2.x >= t1.y-1 and t2.x <= t1.y+1;
id select_type table type possible_keys key key_len ref rows Extra
1 SIMPLE t1 ref y y 5 const 1 Using where
1 SIMPLE t1 ref y y 5 const 1 Using where; Using join cache
1 SIMPLE t2 range x x 5 NULL 3 Using where
explain select * from t1, t1 t2 where t1.y = 2 and t2.x between 0 and t1.y;
id select_type table type possible_keys key key_len ref rows Extra
1 SIMPLE t1 ref y y 5 const 1 Using where
1 SIMPLE t1 ref y y 5 const 1 Using where; Using join cache
1 SIMPLE t2 range x x 5 NULL 2 Using where
explain select * from t1, t1 t2 where t1.y = 2 and t2.x >= 0 and t2.x <= t1.y;
id select_type table type possible_keys key key_len ref rows Extra
1 SIMPLE t1 ref y y 5 const 1 Using where
1 SIMPLE t1 ref y y 5 const 1 Using where; Using join cache
1 SIMPLE t2 range x x 5 NULL 2 Using where
explain select count(*) from t1 where x in (1);
id select_type table type possible_keys key key_len ref rows Extra
......@@ -255,12 +255,12 @@ CREATE TABLE t2 (keya int(11) NOT NULL default '0', KEY j1 (keya));
INSERT INTO t2 VALUES (0),(0),(1),(1),(2),(2);
explain select * from t1, t2 where (t1.key1 <t2.keya + 1) and t2.keya=3;
id select_type table type possible_keys key key_len ref rows Extra
1 SIMPLE t2 ref j1 j1 4 const 1 Using index
1 SIMPLE t2 ref j1 j1 4 const 1 Using index; Using join cache
1 SIMPLE t1 index i1 i1 4 NULL 7 Using where; Using index
explain select * from t1 force index(i1), t2 force index(j1) where
(t1.key1 <t2.keya + 1) and t2.keya=3;
id select_type table type possible_keys key key_len ref rows Extra
1 SIMPLE t2 ref j1 j1 4 const 1 Using index
1 SIMPLE t2 ref j1 j1 4 const 1 Using index; Using join cache
1 SIMPLE t1 index i1 i1 4 NULL 7 Using where; Using index
DROP TABLE t1,t2;
CREATE TABLE t1 (
......
......@@ -376,7 +376,7 @@ a b a b c
3 2 3 1 3
EXPLAIN EXTENDED SELECT * FROM t1,t2 WHERE (t1.a-1,t1.b)=(t2.a-1,t2.b+1);
id select_type table type possible_keys key key_len ref rows filtered Extra
1 SIMPLE t1 index NULL PRIMARY 8 NULL 6 100.00 Using index
1 SIMPLE t1 index NULL PRIMARY 8 NULL 6 100.00 Using index; Using join cache
1 SIMPLE t2 index NULL PRIMARY 12 NULL 7 100.00 Using where; Using index
Warnings:
Note 1003 select `test`.`t1`.`a` AS `a`,`test`.`t1`.`b` AS `b`,`test`.`t2`.`a` AS `a`,`test`.`t2`.`b` AS `b`,`test`.`t2`.`c` AS `c` from `test`.`t1` join `test`.`t2` where (((`test`.`t1`.`a` - 1) = (`test`.`t2`.`a` - 1)) and (`test`.`t1`.`b` = (`test`.`t2`.`b` + 1)))
......
......@@ -607,11 +607,11 @@ id select_type table type possible_keys key key_len ref rows Extra
1 SIMPLE t3 ref period period 4 test.t1.period 4181
explain select * from t3 as t1,t3 where t1.period=t3.period order by t3.period limit 10;
id select_type table type possible_keys key key_len ref rows Extra
1 SIMPLE t3 index period period 4 NULL 41810
1 SIMPLE t3 ALL period NULL NULL NULL 41810 Using filesort
1 SIMPLE t1 ref period period 4 test.t3.period 4181
explain select * from t3 as t1,t3 where t1.period=t3.period order by t1.period limit 10;
id select_type table type possible_keys key key_len ref rows Extra
1 SIMPLE t1 index period period 4 NULL 41810
1 SIMPLE t1 ALL period NULL NULL NULL 41810 Using filesort
1 SIMPLE t3 ref period period 4 test.t1.period 4181
select period from t1;
period
......@@ -1430,7 +1430,7 @@ companynr companynr
41 40
explain select distinct t2.companynr,t4.companynr from t2,t4 where t2.companynr=t4.companynr+1;
id select_type table type possible_keys key key_len ref rows Extra
1 SIMPLE t4 index NULL PRIMARY 1 NULL 12 Using index; Using temporary
1 SIMPLE t4 index NULL PRIMARY 1 NULL 12 Using index; Using temporary; Using join cache
1 SIMPLE t2 ALL NULL NULL NULL NULL 1199 Using where
select t2.fld1,t2.companynr,fld3,period from t3,t2 where t2.fld1 = 38208 and t2.fld1=t3.t2nr and period = 1008 or t2.fld1 = 38008 and t2.fld1 =t3.t2nr and period = 1008;
fld1 companynr fld3 period
......@@ -2362,7 +2362,7 @@ insert into t1 values (1,2), (2,2), (3,2), (4,2);
insert into t2 values (1,3), (2,3), (3,4), (4,4);
explain select * from t1 left join t2 on a=c where d in (4);
id select_type table type possible_keys key key_len ref rows Extra
1 SIMPLE t2 ref c,d d 5 const 2 Using where
1 SIMPLE t2 ref c,d d 5 const 2 Using where; Using join cache
1 SIMPLE t1 ALL a NULL NULL NULL 4 Using where
select * from t1 left join t2 on a=c where d in (4);
a b c d
......@@ -2370,7 +2370,7 @@ a b c d
4 2 4 4
explain select * from t1 left join t2 on a=c where d = 4;
id select_type table type possible_keys key key_len ref rows Extra
1 SIMPLE t2 ref c,d d 5 const 2 Using where
1 SIMPLE t2 ref c,d d 5 const 2 Using where; Using join cache
1 SIMPLE t1 ALL a NULL NULL NULL 4 Using where
select * from t1 left join t2 on a=c where d = 4;
a b c d
......@@ -2716,7 +2716,7 @@ explain select straight_join DISTINCT t2.a,t2.b, t1.c from t1, t3, t2
where (t1.c=t2.a or (t1.c=t3.a and t2.a=t3.b)) and t1.b=556476786 and
t2.b like '%%' order by t2.b limit 0,1;
id select_type table type possible_keys key key_len ref rows Extra
1 SIMPLE t1 ref b,c b 5 const 1 Using where; Using temporary; Using filesort
1 SIMPLE t1 ref b,c b 5 const 1 Using where; Using temporary; Using filesort; Using join cache
1 SIMPLE t3 index PRIMARY,a,b PRIMARY 8 NULL 2 Using index
1 SIMPLE t2 ALL PRIMARY NULL NULL NULL 2 Range checked for each record (index map: 0x1)
DROP TABLE t1,t2,t3;
......@@ -2737,7 +2737,7 @@ INSERT INTO t2 VALUES (1,NULL), (2,10);
ALTER TABLE t1 ENABLE KEYS;
EXPLAIN SELECT STRAIGHT_JOIN SQL_NO_CACHE COUNT(*) FROM t2, t1 WHERE t1.b = t2.b OR t2.b IS NULL;
id select_type table type possible_keys key key_len ref rows Extra
1 SIMPLE t2 index b b 5 NULL 2 Using index
1 SIMPLE t2 index b b 5 NULL 2 Using index; Using join cache
1 SIMPLE t1 ALL NULL NULL NULL NULL 3 Using where
SELECT STRAIGHT_JOIN SQL_NO_CACHE * FROM t2, t1 WHERE t1.b = t2.b OR t2.b IS NULL;
a b a b
......@@ -2747,7 +2747,7 @@ a b a b
2 10 4 10
EXPLAIN SELECT STRAIGHT_JOIN SQL_NO_CACHE COUNT(*) FROM t2, t1 WHERE t1.b = t2.b OR t2.b IS NULL;
id select_type table type possible_keys key key_len ref rows Extra
1 SIMPLE t2 index b b 5 NULL 2 Using index
1 SIMPLE t2 index b b 5 NULL 2 Using index; Using join cache
1 SIMPLE t1 ALL NULL NULL NULL NULL 3 Using where
SELECT STRAIGHT_JOIN SQL_NO_CACHE * FROM t2, t1 WHERE t1.b = t2.b OR t2.b IS NULL;
a b a b
......@@ -2901,11 +2901,11 @@ a
4
EXPLAIN SELECT t1.a FROM t1 STRAIGHT_JOIN t2 ON t1.a=t2.a;
id select_type table type possible_keys key key_len ref rows Extra
1 SIMPLE t1 ALL NULL NULL NULL NULL 5
1 SIMPLE t1 ALL NULL NULL NULL NULL 5 Using join cache
1 SIMPLE t2 ALL NULL NULL NULL NULL 3 Using where
EXPLAIN SELECT t1.a FROM t1 INNER JOIN t2 ON t1.a=t2.a;
id select_type table type possible_keys key key_len ref rows Extra
1 SIMPLE t2 ALL NULL NULL NULL NULL 3
1 SIMPLE t2 ALL NULL NULL NULL NULL 3 Using join cache
1 SIMPLE t1 ALL NULL NULL NULL NULL 5 Using where
DROP TABLE t1,t2;
select x'10' + 0, X'10' + 0, b'10' + 0, B'10' + 0;
......
......@@ -608,11 +608,11 @@ id select_type table type possible_keys key key_len ref rows Extra
1 SIMPLE t3 ref period period 4 test.t1.period 4181
explain select * from t3 as t1,t3 where t1.period=t3.period order by t3.period limit 10;
id select_type table type possible_keys key key_len ref rows Extra
1 SIMPLE t3 index period period 4 NULL 41810
1 SIMPLE t3 ALL period NULL NULL NULL 41810 Using filesort
1 SIMPLE t1 ref period period 4 test.t3.period 4181
explain select * from t3 as t1,t3 where t1.period=t3.period order by t1.period limit 10;
id select_type table type possible_keys key key_len ref rows Extra
1 SIMPLE t1 index period period 4 NULL 41810
1 SIMPLE t1 ALL period NULL NULL NULL 41810 Using filesort
1 SIMPLE t3 ref period period 4 test.t1.period 4181
select period from t1;
period
......@@ -1431,7 +1431,7 @@ companynr companynr
41 40
explain select distinct t2.companynr,t4.companynr from t2,t4 where t2.companynr=t4.companynr+1;
id select_type table type possible_keys key key_len ref rows Extra
1 SIMPLE t4 index NULL PRIMARY 1 NULL 12 Using index; Using temporary
1 SIMPLE t4 index NULL PRIMARY 1 NULL 12 Using index; Using temporary; Using join cache
1 SIMPLE t2 ALL NULL NULL NULL NULL 1199 Using where
select t2.fld1,t2.companynr,fld3,period from t3,t2 where t2.fld1 = 38208 and t2.fld1=t3.t2nr and period = 1008 or t2.fld1 = 38008 and t2.fld1 =t3.t2nr and period = 1008;
fld1 companynr fld3 period
......
......@@ -611,11 +611,11 @@ id select_type table type possible_keys key key_len ref rows Extra
1 SIMPLE t3 ref period period 4 test.t1.period 4181
explain select * from t3 as t1,t3 where t1.period=t3.period order by t3.period limit 10;
id select_type table type possible_keys key key_len ref rows Extra
1 SIMPLE t3 index period period 4 NULL 41810
1 SIMPLE t3 ALL period NULL NULL NULL 41810 Using filesort
1 SIMPLE t1 ref period period 4 test.t3.period 4181
explain select * from t3 as t1,t3 where t1.period=t3.period order by t1.period limit 10;
id select_type table type possible_keys key key_len ref rows Extra
1 SIMPLE t1 index period period 4 NULL 41810
1 SIMPLE t1 ALL period NULL NULL NULL 41810 Using filesort
1 SIMPLE t3 ref period period 4 test.t1.period 4181
select period from t1;
period
......@@ -1434,7 +1434,7 @@ companynr companynr
41 40
explain select distinct t2.companynr,t4.companynr from t2,t4 where t2.companynr=t4.companynr+1;
id select_type table type possible_keys key key_len ref rows Extra
1 SIMPLE t4 index NULL PRIMARY 1 NULL 12 Using index; Using temporary
1 SIMPLE t4 index NULL PRIMARY 1 NULL 12 Using index; Using temporary; Using join cache
1 SIMPLE t2 ALL NULL NULL NULL NULL 1199 Using where
select t2.fld1,t2.companynr,fld3,period from t3,t2 where t2.fld1 = 38208 and t2.fld1=t3.t2nr and period = 1008 or t2.fld1 = 38008 and t2.fld1 =t3.t2nr and period = 1008;
fld1 companynr fld3 period
......
......@@ -904,7 +904,7 @@ a t1.a in (select t2.a from t2,t3 where t3.a=t2.a)
explain extended SELECT t1.a, t1.a in (select t2.a from t2,t3 where t3.a=t2.a) FROM t1;
id select_type table type possible_keys key key_len ref rows filtered Extra
1 PRIMARY t1 index NULL PRIMARY 4 NULL 4 100.00 Using index
2 DEPENDENT SUBQUERY t2 ref_or_null a a 5 func 2 100.00 Using where; Using index
2 DEPENDENT SUBQUERY t2 ref_or_null a a 5 func 2 100.00 Using where; Using index; Using join cache
2 DEPENDENT SUBQUERY t3 ALL NULL NULL NULL NULL 3 100.00 Using where
Warnings:
Note 1003 select `test`.`t1`.`a` AS `a`,<in_optimizer>(`test`.`t1`.`a`,<exists>(select 1 AS `Not_used` from `test`.`t2` join `test`.`t3` where ((`test`.`t3`.`a` = `test`.`t2`.`a`) and ((<cache>(`test`.`t1`.`a`) = `test`.`t2`.`a`) or isnull(`test`.`t2`.`a`))) having <is_not_null_test>(`test`.`t2`.`a`))) AS `t1.a in (select t2.a from t2,t3 where t3.a=t2.a)` from `test`.`t1`
......@@ -1354,7 +1354,7 @@ a
explain extended select * from t2 where t2.a in (select t1.a from t1,t3 where t1.b=t3.a);
id select_type table type possible_keys key key_len ref rows filtered Extra
1 PRIMARY t2 index NULL a 5 NULL 4 100.00 Using where; Using index
2 DEPENDENT SUBQUERY t1 ref a a 5 func 1001 100.00 Using where; Using index
2 DEPENDENT SUBQUERY t1 ref a a 5 func 1001 100.00 Using where; Using index; Using join cache
2 DEPENDENT SUBQUERY t3 index a a 5 NULL 3 100.00 Using where; Using index
Warnings:
Note 1003 select `test`.`t2`.`a` AS `a` from `test`.`t2` where <in_optimizer>(`test`.`t2`.`a`,<exists>(select 1 AS `Not_used` from `test`.`t1` join `test`.`t3` where ((`test`.`t3`.`a` = `test`.`t1`.`b`) and (<cache>(`test`.`t2`.`a`) = `test`.`t1`.`a`))))
......
......@@ -254,7 +254,7 @@ select a,b, oref,
from t2;
id select_type table type possible_keys key key_len ref rows filtered Extra
1 PRIMARY t2 ALL NULL NULL NULL NULL 2 100.00
2 DEPENDENT SUBQUERY t1 ref_or_null a a 5 func 2 100.00 Using where; Full scan on NULL key
2 DEPENDENT SUBQUERY t1 ref_or_null a a 5 func 2 100.00 Using where; Full scan on NULL key; Using join cache
2 DEPENDENT SUBQUERY t4 ALL NULL NULL NULL NULL 100 100.00 Using where
Warnings:
Note 1276 Field or reference 'test.t2.oref' of SELECT #2 was resolved in SELECT #1
......
......@@ -499,7 +499,7 @@ a b
explain (select * from t1 where a=1 and b=10) union (select straight_join t1.a,t2.a from t1,t2 where t1.a=t2.a);
id select_type table type possible_keys key key_len ref rows Extra
1 PRIMARY NULL NULL NULL NULL NULL NULL NULL Impossible WHERE noticed after reading const tables
2 UNION t1 index PRIMARY PRIMARY 4 NULL 4 Using index
2 UNION t1 index PRIMARY PRIMARY 4 NULL 4 Using index; Using join cache
2 UNION t2 index PRIMARY PRIMARY 4 NULL 4 Using where; Using index
NULL UNION RESULT <union1,2> ALL NULL NULL NULL NULL NULL
explain (select * from t1 where a=1) union (select * from t1 where b=1);
......
......@@ -2317,7 +2317,7 @@ id select_type table type possible_keys key key_len ref rows Extra
1 SIMPLE t2 ref a a 10 const,test.t1.b 2 Using where; Using index
EXPLAIN SELECT * FROM v2 WHERE a=1;
id select_type table type possible_keys key key_len ref rows Extra
1 SIMPLE t1 ref a a 5 const 1 Using where; Using index
1 SIMPLE t1 ref a a 5 const 1 Using where; Using index; Using join cache
1 SIMPLE t3 ALL NULL NULL NULL NULL 3 Using where
DROP VIEW v1,v2;
DROP TABLE t1,t2,t3;
......
......@@ -5893,6 +5893,12 @@ make_join_select(JOIN *join,SQL_SELECT *select,COND *cond)
tab->ref.key= -1;
tab->ref.key_parts=0; // Don't use ref key.
join->best_positions[i].records_read= rows2double(tab->quick->records);
/*
We will use join cache here : prevent sorting of the first
table only and sort at the end.
*/
if (i != join->const_tables && join->tables > join->const_tables + 1)
join->full_join= 1;
}
tmp= NULL;
......@@ -12660,6 +12666,12 @@ test_if_skip_sort_order(JOIN_TAB *tab,ORDER *order,ha_rows select_limit,
uint nr;
key_map keys;
/*
filesort() and join cache are usually faster than reading in
index order and not using join cache
*/
if (tab->type == JT_ALL && tab->join->tables > tab->join->const_tables + 1)
DBUG_RETURN(0);
/*
If not used with LIMIT, only use keys if the whole query can be
resolved with a key; This is because filesort() is usually faster than
......@@ -15513,6 +15525,8 @@ static void select_describe(JOIN *join, bool need_tmp_table, bool need_order,
break;
}
}
if (tab->next_select == sub_select_cache)
extra.append(STRING_WITH_LEN("; Using join cache"));
/* Skip initial "; "*/
const char *str= extra.ptr();
......
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