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MDEV-3858 Change JOIN_TAB::records_read from ha_rows to double

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Currently JOIN_TAB::records_read is of type ha_rows.
This is an integer type, which prevents proper selectivity and rows estimates.
This commit is contained in:
unknown
2012-11-15 12:54:50 +02:00
parent dbb8d954fd
commit cd2feb659b
4 changed files with 16 additions and 15 deletions
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8
mysql-test/r/subselect_sj_mat.result
View File

@@ -94,7 +94,7 @@ a1 a2
explain extended
select * from t1i where a1 in (select b1 from t2i where b1 > '0');
id select_type table type possible_keys key key_len ref rows filtered Extra
1 PRIMARY t2i index it2i1,it2i3 it2i1 # NULL 5 40.00 Using where; Using index; LooseScan
1 PRIMARY t2i index it2i1,it2i3 it2i1 # NULL 5 50.00 Using where; Using index; LooseScan
1 PRIMARY t1i ref _it1_idx _it1_idx # _ref_ 1 100.00
Warnings:
Note 1003 select `test`.`t1i`.`a1` AS `a1`,`test`.`t1i`.`a2` AS `a2` from `test`.`t1i` semi join (`test`.`t2i`) where ((`test`.`t1i`.`a1` = `test`.`t2i`.`b1`) and (`test`.`t2i`.`b1` > '0'))
@@ -117,7 +117,7 @@ a1 a2
explain extended
select * from t1i where (a1, a2) in (select b1, b2 from t2i where b1 > '0');
id select_type table type possible_keys key key_len ref rows filtered Extra
1 PRIMARY t2i index it2i1,it2i2,it2i3 it2i3 # NULL 5 40.00 Using where; Using index; LooseScan
1 PRIMARY t2i index it2i1,it2i2,it2i3 it2i3 # NULL 5 50.00 Using where; Using index; LooseScan
1 PRIMARY t1i ref _it1_idx _it1_idx # _ref_ 1 100.00
Warnings:
Note 1003 select `test`.`t1i`.`a1` AS `a1`,`test`.`t1i`.`a2` AS `a2` from `test`.`t1i` semi join (`test`.`t2i`) where ((`test`.`t1i`.`a2` = `test`.`t2i`.`b2`) and (`test`.`t1i`.`a1` = `test`.`t2i`.`b1`) and (`test`.`t2i`.`b1` > '0'))
@@ -319,7 +319,7 @@ where (a1, a2) in (select b1, b2 from t2i where b1 > '0') and
(a1, a2) in (select c1, c2 from t3i
where (c1, c2) in (select b1, b2 from t2i where b2 > '0'));
id select_type table type possible_keys key key_len ref rows filtered Extra
1 PRIMARY t2i index it2i1,it2i2,it2i3 # # # 5 40.00 #
1 PRIMARY t2i index it2i1,it2i2,it2i3 # # # 5 50.00 #
1 PRIMARY t1i ref it1i1,it1i2,it1i3 # # # 1 100.00 #
1 PRIMARY t3i ref it3i1,it3i2,it3i3 # # # 1 100.00 #
1 PRIMARY t2i ref it2i1,it2i2,it2i3 # # # 2 100.00 #
@@ -407,7 +407,7 @@ id select_type table type possible_keys key key_len ref rows filtered Extra
2 MATERIALIZED t2 ALL NULL # # # 5 100.00 #
4 MATERIALIZED t3 ALL NULL # # # 4 100.00 #
3 MATERIALIZED t3 ALL NULL # # # 4 100.00 #
7 UNION t2i index it2i1,it2i2,it2i3 # # # 5 40.00 #
7 UNION t2i index it2i1,it2i2,it2i3 # # # 5 50.00 #
7 UNION t1i ref it1i1,it1i2,it1i3 # # # 1 100.00 #
7 UNION t3i ref it3i1,it3i2,it3i3 # # # 1 100.00 #
7 UNION t2i ref it2i1,it2i2,it2i3 # # # 2 100.00 #

2
sql/item_subselect.cc
View File

@@ -4553,7 +4553,7 @@ double get_fanout_with_deps(JOIN *join, table_map tset)
!tab->emb_sj_nest &&
tab->records_read != 0)
{
fanout *= rows2double(tab->records_read);
fanout *= tab->records_read;
}
}
return fanout;

17
sql/sql_select.cc
View File

@@ -6789,7 +6789,7 @@ void JOIN::get_prefix_cost_and_fanout(uint n_tables,
double JOIN::get_examined_rows()
{
ha_rows examined_rows;
double examined_rows;
double prev_fanout= 1;
JOIN_TAB *tab= first_breadth_first_tab(this, WALK_OPTIMIZATION_TABS);
JOIN_TAB *prev_tab= tab;
@@ -6799,7 +6799,7 @@ double JOIN::get_examined_rows()
while ((tab= next_breadth_first_tab(this, WALK_OPTIMIZATION_TABS, tab)))
{
prev_fanout *= prev_tab->records_read;
examined_rows+= (ha_rows) (tab->get_examined_rows() * prev_fanout);
examined_rows+= tab->get_examined_rows() * prev_fanout;
prev_tab= tab;
}
return examined_rows;
@@ -7704,7 +7704,8 @@ get_best_combination(JOIN *join)
sub-order
*/
SJ_MATERIALIZATION_INFO *sjm= cur_pos->table->emb_sj_nest->sj_mat_info;
j->records= j->records_read= (ha_rows)(sjm->is_sj_scan? sjm->rows : 1);
j->records_read= sjm->is_sj_scan? sjm->rows : 1;
j->records= (ha_rows) j->records_read;
JOIN_TAB *jt;
JOIN_TAB_RANGE *jt_range;
if (!(jt= (JOIN_TAB*)join->thd->alloc(sizeof(JOIN_TAB)*sjm->tables)) ||
@@ -7766,7 +7767,7 @@ get_best_combination(JOIN *join)
Save records_read in JOIN_TAB so that select_describe()/etc don't have
to access join->best_positions[].
*/
j->records_read= (ha_rows)join->best_positions[tablenr].records_read;
j->records_read= join->best_positions[tablenr].records_read;
join->map2table[j->table->tablenr]= j;
/* If we've reached the end of sjm nest, switch back to main sequence */
@@ -10460,7 +10461,7 @@ double JOIN_TAB::scan_time()
ha_rows JOIN_TAB::get_examined_rows()
{
ha_rows examined_rows;
double examined_rows;
if (select && select->quick && use_quick != 2)
examined_rows= select->quick->records;
@@ -10490,7 +10491,7 @@ ha_rows JOIN_TAB::get_examined_rows()
}
}
else
examined_rows= (ha_rows) records_read;
examined_rows= records_read;
return examined_rows;
}
@@ -21972,7 +21973,7 @@ int JOIN::print_explain(select_result_sink *result, uint8 explain_flags,
}
else
{
ha_rows examined_rows= tab->get_examined_rows();
double examined_rows= tab->get_examined_rows();
item_list.push_back(new Item_int((longlong) (ulonglong) examined_rows,
MY_INT64_NUM_DECIMAL_DIGITS));
@@ -21982,7 +21983,7 @@ int JOIN::print_explain(select_result_sink *result, uint8 explain_flags,
{
float f= 0.0;
if (examined_rows)
f= (float) (100.0 * tab->records_read / examined_rows);
f= (100.0 * (float)tab->records_read) / examined_rows;
set_if_smaller(f, 100.0);
item_list.push_back(new Item_float(f, 2));
}

4
sql/sql_select.h
View File

@@ -280,8 +280,8 @@ typedef struct st_join_table {
*/
double read_time;
/* psergey-todo: make the below have type double, like POSITION::records_read? */
ha_rows records_read;
/* Copy of POSITION::records_read, set by get_best_combination() */
double records_read;
/* Startup cost for execution */
double startup_cost;