Commit bcf16fa6 authored by Igor Babaev's avatar Igor Babaev

Merge.

parents ed93e55b 3e0f63c1
......@@ -756,7 +756,7 @@ INSERT INTO t1(a, b, c) VALUES (1, 1, 1),
(1, 2, 3);
EXPLAIN SELECT DISTINCT a, b, d, c FROM t1;
id select_type table type possible_keys key key_len ref rows Extra
1 SIMPLE t1 range NULL a 16 NULL 7 Using index for group-by
1 SIMPLE t1 index NULL a 16 NULL 6 Using index
SELECT DISTINCT a, b, d, c FROM t1;
a b d c
1 1 0 1
......
......@@ -236,12 +236,14 @@ SET storage_engine=@old_engine;
#
CREATE TABLE t1(a BLOB, b VARCHAR(255) CHARSET LATIN1, c INT,
KEY(b, c, a(765))) ENGINE=INNODB;
INSERT INTO t1(a, b, c) VALUES ('', 'a', 0), ('', 'a', null), ('', 'a', 0);
INSERT INTO t1(a, b, c) VALUES
('', 'a', 0), ('', 'a', null), ('', 'a', 0), ('', 'a', null), ('', 'a', 0);
ANALYZE TABLE t1;
SELECT MIN(c) FROM t1 GROUP BY b;
MIN(c)
0
EXPLAIN SELECT MIN(c) FROM t1 GROUP BY b;
id select_type table type possible_keys key key_len ref rows Extra
1 SIMPLE t1 range NULL b 263 NULL 4 Using index for group-by
1 SIMPLE t1 range NULL b 263 NULL 3 Using index for group-by
DROP TABLE t1;
End of 5.5 tests
......@@ -1524,7 +1524,7 @@ id select_type table type possible_keys key key_len ref rows Extra
EXPLAIN SELECT a FROM t1 FORCE INDEX FOR JOIN (i2)
FORCE INDEX FOR GROUP BY (i2) GROUP BY a;
id select_type table type possible_keys key key_len ref rows Extra
1 SIMPLE t1 range NULL i2 4 NULL 145 Using index for group-by
1 SIMPLE t1 index NULL i2 9 NULL 144 Using index
EXPLAIN SELECT a FROM t1 USE INDEX () IGNORE INDEX (i2);
id select_type table type possible_keys key key_len ref rows Extra
1 SIMPLE t1 ALL NULL NULL NULL NULL 144
......@@ -1957,12 +1957,12 @@ UNIQUE INDEX idx (col1));
INSERT INTO t1 VALUES (1),(2),(3),(4),(5),(6),(7),(8),(9),(10),
(11),(12),(13),(14),(15),(16),(17),(18),(19),(20);
EXPLAIN SELECT col1 AS field1, col1 AS field2
FROM t1 GROUP BY field1, field2+0;;
FROM t1 GROUP BY field1, field2;;
id select_type table type possible_keys key key_len ref rows Extra
1 SIMPLE t1 index NULL idx 5 NULL 20 Using index; Using temporary; Using filesort
1 SIMPLE t1 index NULL idx 5 NULL 20 Using index
FLUSH STATUS;
SELECT col1 AS field1, col1 AS field2
FROM t1 GROUP BY field1, field2+0;;
FROM t1 GROUP BY field1, field2;;
field1 field2
1 1
2 2
......@@ -1986,7 +1986,7 @@ field1 field2
20 20
SHOW SESSION STATUS LIKE 'Sort_scan%';
Variable_name Value
Sort_scan 1
Sort_scan 0
EXPLAIN SELECT SQL_BIG_RESULT col1 AS field1, col1 AS field2
FROM t1 GROUP BY field1, field2;;
id select_type table type possible_keys key key_len ref rows Extra
......@@ -2320,7 +2320,7 @@ a int,
b varchar(1),
KEY (b,a)
);
INSERT INTO t1 VALUES (1,NULL),(0,'a');
INSERT INTO t1 VALUES (1,NULL),(0,'a'),(1,NULL),(0,'a');
EXPLAIN SELECT SQL_BUFFER_RESULT MIN(a), b FROM t1 WHERE t1.b = 'a' GROUP BY b;
id select_type table type possible_keys key key_len ref rows Extra
......
drop table if exists t1;
create table t1 (
a1 char(64), a2 char(64), b char(16), c char(16) not null, d char(16), dummy char(64) default ' '
a1 char(64), a2 char(64), b char(16), c char(16) not null, d char(16), dummy char(248) default ' '
);
insert into t1 (a1, a2, b, c, d) values
('a','a','a','a111','xy1'),('a','a','a','b111','xy2'),('a','a','a','c111','xy3'),('a','a','a','d111','xy4'),
......@@ -43,7 +43,7 @@ Table Op Msg_type Msg_text
test.t1 analyze status Table is already up to date
drop table if exists t2;
create table t2 (
a1 char(64), a2 char(64) not null, b char(16), c char(16), d char(16), dummy char(64) default ' '
a1 char(64), a2 char(64) not null, b char(16), c char(16), d char(16), dummy char(248) default ' '
);
insert into t2 select * from t1;
insert into t2 (a1, a2, b, c, d) values
......@@ -2649,6 +2649,7 @@ DROP TABLE t1;
CREATE TABLE t (a INT, b INT, INDEX (a,b));
INSERT INTO t VALUES (2,0), (2,0), (2,1), (2,1);
INSERT INTO t SELECT * FROM t;
INSERT INTO t SELECT * FROM t;
# test MIN
#should use range with index for group by
EXPLAIN
......@@ -3281,6 +3282,7 @@ drop table t1;
#
CREATE TABLE t1 (a int, b int, KEY (b, a)) ;
INSERT INTO t1 VALUES (0,99),(9,99),(4,0),(7,0),(99,0),(7,0),(8,0),(99,0),(1,0);
INSERT INTO t1 VALUES (0,99),(9,99),(4,0),(7,0),(99,0),(7,0),(8,0),(99,0),(1,0);
CREATE TABLE t2 (c int) ;
INSERT INTO t2 VALUES (0),(1);
EXPLAIN
......@@ -3303,10 +3305,10 @@ MIN(a) b
EXPLAIN
SELECT MIN(a), b FROM t1 WHERE a > ( SELECT min(c) FROM t2, t1 t1a, t1 t1b WHERE c = 0 ) GROUP BY b;
id select_type table type possible_keys key key_len ref rows Extra
1 PRIMARY t1 index NULL b 10 NULL 9 Using where; Using index
1 PRIMARY t1 index NULL b 10 NULL 18 Using where; Using index
2 SUBQUERY t2 ALL NULL NULL NULL NULL 2 Using where
2 SUBQUERY t1a index NULL b 10 NULL 9 Using index; Using join buffer (flat, BNL join)
2 SUBQUERY t1b index NULL b 10 NULL 9 Using index; Using join buffer (incremental, BNL join)
2 SUBQUERY t1a index NULL b 10 NULL 18 Using index; Using join buffer (flat, BNL join)
2 SUBQUERY t1b index NULL b 10 NULL 18 Using index; Using join buffer (incremental, BNL join)
SELECT MIN(a), b FROM t1 WHERE a > ( SELECT min(c) FROM t2, t1 t1a, t1 t1b WHERE c = 0 ) GROUP BY b;
MIN(a) b
1 0
......
......@@ -180,7 +180,12 @@ SET storage_engine=@old_engine;
CREATE TABLE t1(a BLOB, b VARCHAR(255) CHARSET LATIN1, c INT,
KEY(b, c, a(765))) ENGINE=INNODB;
INSERT INTO t1(a, b, c) VALUES ('', 'a', 0), ('', 'a', null), ('', 'a', 0);
INSERT INTO t1(a, b, c) VALUES
('', 'a', 0), ('', 'a', null), ('', 'a', 0), ('', 'a', null), ('', 'a', 0);
-- disable_result_log
ANALYZE TABLE t1;
-- enable_result_log
SELECT MIN(c) FROM t1 GROUP BY b;
EXPLAIN SELECT MIN(c) FROM t1 GROUP BY b;
......
......@@ -1334,7 +1334,7 @@ INSERT INTO t1 VALUES (1),(2),(3),(4),(5),(6),(7),(8),(9),(10),
(11),(12),(13),(14),(15),(16),(17),(18),(19),(20);
let $query0=SELECT col1 AS field1, col1 AS field2
FROM t1 GROUP BY field1, field2+0;
FROM t1 GROUP BY field1, field2;
# Needs to be range to exercise bug
--eval EXPLAIN $query0;
......@@ -1496,8 +1496,7 @@ CREATE TABLE t1 (
b varchar(1),
KEY (b,a)
);
INSERT INTO t1 VALUES (1,NULL),(0,'a');
INSERT INTO t1 VALUES (1,NULL),(0,'a'),(1,NULL),(0,'a');
let $query=
SELECT SQL_BUFFER_RESULT MIN(a), b FROM t1 WHERE t1.b = 'a' GROUP BY b;
......
......@@ -15,7 +15,7 @@ drop table if exists t1;
--enable_warnings
create table t1 (
a1 char(64), a2 char(64), b char(16), c char(16) not null, d char(16), dummy char(64) default ' '
a1 char(64), a2 char(64), b char(16), c char(16) not null, d char(16), dummy char(248) default ' '
);
insert into t1 (a1, a2, b, c, d) values
......@@ -65,7 +65,7 @@ drop table if exists t2;
--enable_warnings
create table t2 (
a1 char(64), a2 char(64) not null, b char(16), c char(16), d char(16), dummy char(64) default ' '
a1 char(64), a2 char(64) not null, b char(16), c char(16), d char(16), dummy char(248) default ' '
);
insert into t2 select * from t1;
# add few rows with NULL's in the MIN/MAX column
......@@ -1058,6 +1058,7 @@ DROP TABLE t1;
CREATE TABLE t (a INT, b INT, INDEX (a,b));
INSERT INTO t VALUES (2,0), (2,0), (2,1), (2,1);
INSERT INTO t SELECT * FROM t;
INSERT INTO t SELECT * FROM t;
--echo # test MIN
--echo #should use range with index for group by
......@@ -1257,6 +1258,7 @@ drop table t1;
CREATE TABLE t1 (a int, b int, KEY (b, a)) ;
INSERT INTO t1 VALUES (0,99),(9,99),(4,0),(7,0),(99,0),(7,0),(8,0),(99,0),(1,0);
INSERT INTO t1 VALUES (0,99),(9,99),(4,0),(7,0),(99,0),(7,0),(8,0),(99,0),(1,0);
CREATE TABLE t2 (c int) ;
INSERT INTO t2 VALUES (0),(1);
......
......@@ -13429,7 +13429,7 @@ SEL_ARG * get_index_range_tree(uint index, SEL_TREE* range_tree, PARAM *param,
DESCRIPTION
This method computes the access cost of a TRP_GROUP_MIN_MAX instance and
the number of rows returned. It updates this->read_cost and this->records.
the number of rows returned.
NOTES
The cost computation distinguishes several cases:
......@@ -13485,7 +13485,6 @@ void cost_group_min_max(TABLE* table, KEY *index_info, uint used_key_parts,
double p_overlap; /* Probability that a sub-group overlaps two blocks. */
double quick_prefix_selectivity;
double io_cost;
double cpu_cost= 0; /* TODO: CPU cost of index_read calls? */
DBUG_ENTER("cost_group_min_max");
table_records= table->stat_records();
......@@ -13533,11 +13532,25 @@ void cost_group_min_max(TABLE* table, KEY *index_info, uint used_key_parts,
(double) num_blocks;
/*
TODO: If there is no WHERE clause and no other expressions, there should be
no CPU cost. We leave it here to make this cost comparable to that of index
scan as computed in SQL_SELECT::test_quick_select().
CPU cost must be comparable to that of an index scan as computed
in SQL_SELECT::test_quick_select(). When the groups are small,
e.g. for a unique index, using index scan will be cheaper since it
reads the next record without having to re-position to it on every
group. To make the CPU cost reflect this, we estimate the CPU cost
as the sum of:
1. Cost for evaluating the condition (similarly as for index scan).
2. Cost for navigating the index structure (assuming a b-tree).
Note: We only add the cost for one comparision per block. For a
b-tree the number of comparisons will be larger.
TODO: This cost should be provided by the storage engine.
*/
cpu_cost= (double) num_groups / TIME_FOR_COMPARE;
const double tree_traversal_cost=
ceil(log(static_cast<double>(table_records))/
log(static_cast<double>(keys_per_block))) *
1/double(2*TIME_FOR_COMPARE);
const double cpu_cost= num_groups *
(tree_traversal_cost + 1/double(TIME_FOR_COMPARE));
*read_cost= io_cost + cpu_cost;
*records= num_groups;
......
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