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Fixed bug mdev-4363.

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When calculating the selectivity of a range in the function
get_column_range_cardinality a check whether NULL values are
included into into the range must be done.
This commit is contained in:
Igor Babaev
2013-04-06 17:18:51 -07:00
parent 10f0530b22
commit e3bf08d4b1
6 changed files with 127 additions and 7 deletions
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10
sql/sql_statistics.cc
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@ -3339,7 +3339,8 @@ double get_column_avg_frequency(Field * field)
double get_column_range_cardinality(Field *field,
key_range *min_endp,
key_range *max_endp)
key_range *max_endp,
uint range_flag)
{
double res;
TABLE *table= field->table;
@ -3353,12 +3354,15 @@ double get_column_range_cardinality(Field *field,
double col_non_nulls= tab_records - col_nulls;
bool nulls_incl= field->null_ptr && min_endp && min_endp->key[0] &&
!(range_flag & NEAR_MIN);
if (col_non_nulls < 1)
res= 0;
else if (min_endp && max_endp && min_endp->length == max_endp->length &&
!memcmp(min_endp->key, max_endp->key, min_endp->length))
{
if (field->null_ptr && min_endp->key[0])
if (nulls_incl)
{
/* This is null single point range */
res= col_nulls;
@ -3416,6 +3420,8 @@ double get_column_range_cardinality(Field *field,
}
else
res= col_non_nulls;
if (nulls_incl)
res+= col_nulls;
}
return res;
}