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The pilot patch for mwl#253.

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This commit is contained in:
Igor Babaev
2013-03-11 07:44:24 -07:00
parent 938d47dcdc
commit fc1c8ffdad
25 changed files with 1219 additions and 34 deletions
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49
sql/sql_statistics.cc
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@ -26,6 +26,7 @@
#include "sql_base.h"
#include "key.h"
#include "sql_statistics.h"
#include "opt_range.h"
#include "my_atomic.h"
/*
@ -3054,3 +3055,51 @@ void set_statistics_for_table(THD *thd, TABLE *table)
key_info->read_stats->get_avg_frequency(0) > 0.5);
}
}
double get_column_avg_frequency(Field * field)
{
double res;
TABLE *table= field->table;
Column_statistics *col_stats= table->s->field[field->field_index]->read_stats;
if (!col_stats)
res= table->stat_records();
else
res= col_stats->get_avg_frequency();
return res;
}
double get_column_range_cardinality(Field *field,
key_range *min_endp,
key_range *max_endp)
{
double res;
TABLE *table= field->table;
Column_statistics *col_stats= table->field[field->field_index]->read_stats;
if (!col_stats)
res= table->stat_records();
else if (min_endp->length == max_endp->length &&
!memcmp(min_endp->key, max_endp->key, min_endp->length))
{
res= col_stats->get_avg_frequency();
}
else
{
if (col_stats->min_value && col_stats->max_value)
{
store_key_image_to_rec(field, (uchar *) min_endp->key, min_endp->length);
double min_mp_pos= field->middle_point_pos(col_stats->min_value,
col_stats->max_value);
store_key_image_to_rec(field, (uchar *) max_endp->key, max_endp->length);
double max_mp_pos= field->middle_point_pos(col_stats->min_value,
col_stats->max_value);
res= table->stat_records() * (max_mp_pos - min_mp_pos);
}
else
res= table->stat_records();
}
return res;
}