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Code cleanup part #1

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This commit is contained in:
Sergei Petrunia
2021-08-27 22:28:59 +03:00
parent f76e310ace
commit 72c0ba43b2
3 changed files with 83 additions and 82 deletions
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83
sql/sql_statistics.h
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@ -157,22 +157,17 @@ public:
virtual uint get_width()=0;
virtual void init_for_collection(MEM_ROOT *mem_root, Histogram_type htype_arg, ulonglong size)=0;
virtual void init_for_collection(MEM_ROOT *mem_root, Histogram_type htype_arg,
ulonglong size)=0;
virtual bool is_available()=0;
virtual bool is_usable(THD *thd)=0;
virtual void set_values(uchar * values)=0;
virtual uchar *get_values()=0;
virtual void set_size(ulonglong sz)=0;
virtual double point_selectivity(Field *field, key_range *endpoint, double avg_selection)=0;
virtual double point_selectivity(Field *field, key_range *endpoint,
double avg_selection)=0;
virtual double range_selectivity(Field *field, key_range *min_endp,
key_range *max_endp)=0;
key_range *max_endp)=0;
// Legacy: return the size of the histogram on disk.
// This will be stored in mysql.column_stats.hist_size column.
@ -181,6 +176,11 @@ public:
virtual ~Histogram_base()= default;
};
/*
A Height-balanced histogram that stores numeric fractions
*/
class Histogram_binary : public Histogram_base
{
public:
@ -274,17 +274,12 @@ private:
return i;
}
uchar *get_values() override { return (uchar *) values; }
public:
void init_for_collection(MEM_ROOT *mem_root, Histogram_type htype_arg, ulonglong size) override;
// Note: these two are used only for saving the JSON text:
void set_values (uchar *vals) override { values= (uchar *) vals; }
void set_size (ulonglong sz) override { size= (uint8) sz; }
uint get_size() override {return (uint)size;}
bool is_available() override { return get_size() > 0 && get_values(); }
bool is_available() override { return get_size() > 0 && (values!=NULL); }
/*
This function checks that histograms should be usable only when
@ -328,58 +323,57 @@ public:
}
double range_selectivity(Field *field, key_range *min_endp,
key_range *max_endp) override;
key_range *max_endp) override;
/*
Estimate selectivity of "col=const" using a histogram
*/
double point_selectivity(Field *field, key_range *endpoint, double avg_sel) override;
double point_selectivity(Field *field, key_range *endpoint,
double avg_sel) override;
};
/*
An equi-height histogram which stores real values for bucket bounds.
*/
class Histogram_json : public Histogram_base
{
private:
Histogram_type type;
uint8 size; /* Number of elements in the histogram*/
/*
GSOC-TODO: This is used for storing collected JSON text. Rename it
accordingly.
*/
uchar *values;
// List of values in string form.
/*
GSOC-TODO: We don't need to save this. It can be a local variable in
parse().
Eventually we should get rid of this at all, as we can convert the
endpoints and add them to histogram_bounds as soon as we've read them.
*/
std::vector<std::string> hist_buckets_text;
/* Collection-time only: collected histogram in the JSON form. */
uchar *json_text;
// Array of histogram bucket endpoints in KeyTupleFormat.
std::vector<std::string> histogram_bounds;
public:
bool parse(MEM_ROOT *mem_root, Field *field, Histogram_type type_arg,
const uchar *ptr, uint size) override;
const uchar *ptr, uint size) override;
void serialize(Field *field) override;
// returns number of buckets in the histogram
uint get_width() override
{
return size;
};
return size;
}
Histogram_type get_type() override
{
return JSON_HB;
}
void set_size (ulonglong sz) override {size = (uint8) sz; }
void set_json_text(ulonglong sz, uchar *json_text_arg)
{
size = (uint8) sz;
json_text= json_text_arg;
}
uint get_size() override {
uint get_size() override
{
return size;
}
@ -393,15 +387,10 @@ public:
is_available();
}
void set_values (uchar *vals) override { values= (uchar *) vals; }
uchar *get_values() override { return (uchar *) values; }
double point_selectivity(Field *field, key_range *endpoint, double avg_selection) override;
double point_selectivity(Field *field, key_range *endpoint,
double avg_selection) override;
double range_selectivity(Field *field, key_range *min_endp,
key_range *max_endp) override;
key_range *max_endp) override;
/*
* Returns the index of the biggest histogram value that is smaller than endpoint
*/