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Renamed the virtual method middle_point_pos for the class Field to
pos_in_interval.
This commit is contained in:
Igor Babaev
2013-04-15 22:43:07 -07:00
parent f4cd2b37b1
commit b12b3cae85
6 changed files with 318 additions and 48 deletions
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73
sql/opt_range.cc
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@ -3222,6 +3222,26 @@ int SQL_SELECT::test_quick_select(THD *thd, key_map keys_to_use,
* Condition selectivity module
****************************************************************************/
/*
Build descriptors of pseudo-indexes over columns to perform range analysis
SYNOPSIS
create_key_parts_for_pseudo_indexes()
param IN/OUT data structure for the descriptors to be built
used_fields bitmap of columns for which the descriptors are to be built
DESCRIPTION
For each column marked in the bitmap used_fields the function builds
a descriptor of a single-component pseudo-index over this column that
can be used for the range analysis of the predicates over this columns.
The descriptors are created in the memory of param->mem_root.
RETURN
FALSE in the case of success
TRUE otherwise
*/
static
bool create_key_parts_for_pseudo_indexes(RANGE_OPT_PARAM *param,
MY_BITMAP *used_fields)
@ -3275,6 +3295,31 @@ bool create_key_parts_for_pseudo_indexes(RANGE_OPT_PARAM *param,
}
/*
Estimate the number of rows in all ranges built for a column
by the range optimizer
SYNOPSIS
records_in_column_ranges()
param the data structure to access descriptors of pseudo indexes
built over columns used in the condition of the processed query
idx the index of the descriptor of interest in param
tree the tree representing ranges built for the interesting column
DESCRIPTION
This function retrieves the ranges represented by the SEL_ARG 'tree' and
for each of them r it calls the function get_column_range_cardinality()
that estimates the number of expected rows in r. It is assumed that param
is the data structure containing the descriptors of pseudo-indexes that
has been built to perform range analysis of the range conditions imposed
on the columns used in the processed query, while idx is the index of the
descriptor created in 'param' exactly for the column for which 'tree'
has been built by the range optimizer.
RETURN
the number of rows in the retrieved ranges
*/
static
double records_in_column_ranges(PARAM *param, uint idx,
SEL_ARG *tree)
@ -3322,6 +3367,29 @@ double records_in_column_ranges(PARAM *param, uint idx,
}
/*
Calculate the selectivity of the condition imposed on the rows of a table
SYNOPSIS
calculate_cond_selectivity_for_table()
thd the context handle
table the table of interest
cond conditions imposed on the rows of the table
DESCRIPTION
This function calculates the selectivity of range conditions cond imposed
on the rows of 'table' in the processed query.
The calculated selectivity is assigned to the field table->cond_selectivity.
NOTE
Currently the selectivities of range conditions over different columns are
considered independent.
RETURN
FALSE on success
TRUE otherwise
*/
bool calculate_cond_selectivity_for_table(THD *thd, TABLE *table, Item *cond)
{
uint keynr;
@ -3338,6 +3406,11 @@ bool calculate_cond_selectivity_for_table(THD *thd, TABLE *table, Item *cond)
if (thd->variables.optimizer_use_condition_selectivity > 2 &&
!bitmap_is_clear_all(used_fields))
{
/*
Calculate the selectivity of the range conditions not supported
by any index
*/
PARAM param;
MEM_ROOT alloc;
SEL_TREE *tree;