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Added the type of histogram for mwl #253.

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Introduced double precision height-balanced histograms.
This commit is contained in:
Igor Babaev
2013-03-30 18:57:07 -07:00
parent e59e529635
commit 9e1ca1053b
15 changed files with 695 additions and 265 deletions
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22
sql/sql_statistics.cc
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@ -928,6 +928,9 @@ public:
case COLUMN_STAT_HIST_SIZE:
stat_field->store(table_field->collected_stats->histogram.get_size());
break;
case COLUMN_STAT_HIST_TYPE:
stat_field->store(table_field->collected_stats->histogram.get_type());
break;
case COLUMN_STAT_HISTOGRAM:
const char * col_histogram=
(const char *) (table_field->collected_stats->histogram.get_values());
@ -971,7 +974,7 @@ public:
char buff[MAX_FIELD_WIDTH];
String val(buff, sizeof(buff), &my_charset_utf8_bin);
for (uint i= COLUMN_STAT_MIN_VALUE; i <= COLUMN_STAT_HIST_SIZE; i++)
for (uint i= COLUMN_STAT_MIN_VALUE; i <= COLUMN_STAT_HIST_TYPE; i++)
{
Field *stat_field= stat_table->field[i];
@ -1007,6 +1010,10 @@ public:
case COLUMN_STAT_HIST_SIZE:
table_field->read_stats->histogram.set_size(stat_field->val_int());
break;
case COLUMN_STAT_HIST_TYPE:
Histogram_type hist_type= (Histogram_type) (stat_field->val_int());
table_field->read_stats->histogram.set_type(hist_type);
break;
}
}
}
@ -1238,7 +1245,7 @@ class Histogram_builder
Field *min_value;
Field *max_value;
Histogram *histogram;
uint hist_size;
uint hist_width;
double bucket_capacity;
uint curr_bucket;
ulonglong count;
@ -1252,8 +1259,8 @@ public:
min_value= col_stats->min_value;
max_value= col_stats->max_value;
histogram= &col_stats->histogram;
hist_size= histogram->get_size();
bucket_capacity= (double) records / (hist_size + 1);
hist_width= histogram->get_width();
bucket_capacity= (double) records / (hist_width + 1);
curr_bucket= 0;
count= 0;
count_distinct= 0;
@ -1265,7 +1272,7 @@ public:
{
count_distinct++;
count+= elem_cnt;
if (curr_bucket == hist_size)
if (curr_bucket == hist_width)
return 0;
if (count > bucket_capacity * (curr_bucket + 1))
{
@ -1273,7 +1280,7 @@ public:
histogram->set_value(curr_bucket,
column->middle_point_pos(min_value, max_value));
curr_bucket++;
while (curr_bucket != hist_size &&
while (curr_bucket != hist_width &&
count > bucket_capacity * (curr_bucket + 1))
{
histogram->set_prev_value(curr_bucket);
@ -1794,6 +1801,7 @@ int alloc_statistics_for_table(THD* thd, TABLE *table)
columns++;
}
uint hist_size= thd->variables.histogram_size;
Histogram_type hist_type= (Histogram_type) (thd->variables.histogram_type);
uchar *histogram= NULL;
if (hist_size > 0)
histogram= (uchar *) alloc_root(&table->mem_root, hist_size * columns);
@ -1818,6 +1826,7 @@ int alloc_statistics_for_table(THD* thd, TABLE *table)
if (bitmap_is_set(table->read_set, (*field_ptr)->field_index))
{
column_stats->histogram.set_size(hist_size);
column_stats->histogram.set_type(hist_type);
column_stats->histogram.set_values(histogram);
histogram+= hist_size;
}
@ -2200,6 +2209,7 @@ void Column_statistics_collected::finish(ha_rows rows)
set_not_null(COLUMN_STAT_HIST_SIZE);
if (hist_size && distincts)
{
set_not_null(COLUMN_STAT_HIST_TYPE);
histogram.set_values(count_distinct->get_histogram());
set_not_null(COLUMN_STAT_HISTOGRAM);
}