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Use generic Histogram_base class for Histogram_builders

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This fixes the wrong calculation for avg_frequency in json histograms
by replacing the specific histogram objects with the generic Histogram_base class.

It also restores get/set size functions as they were useful in calculating fields
for binary histogram.

Signed-off-by: Michael Okoko <okokomichaels@outlook.com>
This commit is contained in:
Michael Okoko
2021-08-11 06:58:18 +01:00
committed by Sergei Petrunia
parent 21e0f5487f
commit 69f24c238e
3 changed files with 32 additions and 44 deletions
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48
sql/sql_statistics.cc
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@@ -1082,7 +1082,7 @@ public:
// Note: this is dumb. the histogram size is stored with the
// histogram!
stat_field->store(stats->histogram_?
stats->histogram_->get_width() : 0);
stats->histogram_->get_size() : 0);
break;
case COLUMN_STAT_HIST_TYPE:
if (stats->histogram_)
@@ -1269,7 +1269,7 @@ bool Histogram_binary::parse(MEM_ROOT *mem_root, Field *, Histogram_type type_ar
*/
void Histogram_binary::serialize(Field *field)
{
field->store((char*)get_values(), get_width(), &my_charset_bin);
field->store((char*)get_values(), get_size(), &my_charset_bin);
}
void Histogram_binary::init_for_collection(MEM_ROOT *mem_root,
@@ -1292,6 +1292,7 @@ void Histogram_json::init_for_collection(MEM_ROOT *mem_root, Histogram_type htyp
bool Histogram_json::parse(MEM_ROOT *mem_root, Field *field, Histogram_type type_arg, const uchar *ptr, uint size_arg)
{
DBUG_ENTER("Histogram_json::parse");
size = (uint8) size_arg;
type = type_arg;
const char *json = (char *)ptr;
int vt;
@@ -1545,7 +1546,7 @@ double Histogram_json::range_selectivity_new(Field *field, key_range *min_endp,
void Histogram_json::serialize(Field *field)
{
field->store((char*)values, strlen((char*)values),
field->store((char*)get_values(), strlen((char*)get_values()),
&my_charset_bin);
}
@@ -1866,13 +1867,13 @@ public:
class Histogram_builder
{
private:
public:
Field *column; /* table field for which the histogram is built */
uint col_length; /* size of this field */
ha_rows records; /* number of records the histogram is built for */
Field *min_value; /* pointer to the minimal value for the field */
Field *max_value; /* pointer to the maximal value for the field */
Histogram_binary *histogram; /* the histogram location */
Histogram_base *histogram; /* the histogram location */
uint hist_width; /* the number of points in the histogram */
double bucket_capacity; /* number of rows in a bucket of the histogram */
uint curr_bucket; /* number of the current bucket to be built */
@@ -1881,14 +1882,13 @@ private:
/* number of distinct values that occured only once */
ulonglong count_distinct_single_occurence;
public:
Histogram_builder(Field *col, uint col_len, ha_rows rows)
: column(col), col_length(col_len), records(rows)
{
Column_statistics *col_stats= col->collected_stats;
min_value= col_stats->min_value;
max_value= col_stats->max_value;
histogram= dynamic_cast<Histogram_binary *>(col_stats->histogram_);
histogram= col_stats->histogram_;
hist_width= histogram->get_width();
bucket_capacity= (double) records / (hist_width + 1);
curr_bucket= 0;
@@ -1918,13 +1918,13 @@ public:
if (count > bucket_capacity * (curr_bucket + 1))
{
column->store_field_value((uchar *) elem, col_length);
histogram->set_value(curr_bucket,
((Histogram_binary *)histogram)->set_value(curr_bucket,
column->pos_in_interval(min_value, max_value));
curr_bucket++;
while (curr_bucket != hist_width &&
count > bucket_capacity * (curr_bucket + 1))
{
histogram->set_prev_value(curr_bucket);
((Histogram_binary *)histogram)->set_prev_value(curr_bucket);
curr_bucket++;
}
}
@@ -1934,35 +1934,13 @@ public:
class Histogram_builder_json : public Histogram_builder
{
Field *column; /* table field for which the histogram is built */
uint col_length; /* size of this field */
ha_rows records; /* number of records the histogram is built for */
Field *min_value; /* pointer to the minimal value for the field */
Field *max_value; /* pointer to the maximal value for the field */
Histogram_json *histogram; /* the histogram location */
uint hist_width; /* the number of points in the histogram */
double bucket_capacity; /* number of rows in a bucket of the histogram */
uint curr_bucket; /* number of the current bucket to be built */
ulonglong count; /* number of values retrieved */
ulonglong count_distinct; /* number of distinct values retrieved */
/* number of distinct values that occured only once */
ulonglong count_distinct_single_occurence;
std::vector<std::string> bucket_bounds = {};
std::vector<std::string> bucket_bounds;
public:
Histogram_builder_json(Field *col, uint col_len, ha_rows rows)
: column(col), col_length(col_len), records(rows)
: Histogram_builder(col, col_len, rows)
{
Column_statistics *col_stats= col->collected_stats;
min_value= col_stats->min_value;
max_value= col_stats->max_value;
histogram= dynamic_cast<Histogram_json *>(col_stats->histogram_);
hist_width= histogram->get_width();
bucket_capacity= (double) records / (hist_width + 1);
curr_bucket= 0;
count= 0;
count_distinct= 0;
count_distinct_single_occurence= 0;
bucket_bounds = {};
}
~Histogram_builder_json() override = default;
@@ -1995,7 +1973,7 @@ public:
writer->end_array();
histogram->set_size(bucket_bounds.size());
Binary_string *json_string = (Binary_string *) writer->output.get_string();
histogram->set_values((uchar *) json_string->c_ptr());
((Histogram_json *)histogram)->set_values((uchar *) json_string->c_ptr());
}
};