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Changed the type of all double columns in the system statistical tables

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mysql.column_stat, mysql.table_stat for the type DECIMAL(12,4).
When cached the values from these columns are multiplied by factor 10^5
and stored as ulong numbers now.
This commit is contained in:
Igor Babaev
2012-06-25 22:33:07 -07:00
parent f549f495f7
commit 4ff6fd34da
12 changed files with 339 additions and 325 deletions
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23
sql/structs.h
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@ -124,14 +124,28 @@ typedef struct st_key {
/* Statistical data on an index prefixes */
class Index_statistics
{
public:
private:
static const uint Scale_factor_avg_frequency= 100000;
/*
The k-th element of this array contains the ratio N/D,
The k-th element of this array contains the ratio N/D
multiplied by the scale factor Scale_factor_avg_frequency,
where N is the number of index entries without nulls
in the first k components, and D is the number of distinct
k-component prefixes among them
*/
double *avg_frequency;
ulong *avg_frequency;
public:
void init_avg_frequency(ulong *ptr) { avg_frequency= ptr; }
bool avg_frequency_is_set() { return avg_frequency != NULL; }
double get_avg_frequency(uint i)
{
return (double) avg_frequency[i] / Scale_factor_avg_frequency;
}
void set_avg_frequency(uint i, double val)
{
avg_frequency[i]= (ulong) (val * Scale_factor_avg_frequency);
}
};
/*
@ -159,8 +173,7 @@ typedef struct st_key {
if (rec_per_key == 0)
return 0;
return (is_statistics_from_stat_tables ?
(ulong) (100 * read_stat.avg_frequency[i]) / (double) 100 :
(double) rec_per_key[i]);
read_stat.get_avg_frequency(i) : (double) rec_per_key[i]);
}
} KEY;