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MDEV-30806: ANALYZE FORMAT=JSON: better support for BNL and BNL-H joins

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In block-nl-join, add:

- r_loops - this shows how many incoming record combinations this
  query plan node had.

- r_effective_rows - this shows the average number of matching rows
  that this table had for each incoming record combination. This is
  comparable with r_rows in non-blocked access methods.
  For BNL-joins, it is always equal to
   $.table.r_rows * $.table.r_filtered
  For BNL-H joins the value cannot be computed from other values

Reviewed by: Monty <monty@mariadb.org>
This commit is contained in:
Sergei Petrunia
2023-03-07 19:49:57 +03:00
parent 169def14f6
commit dc1d6213f9
14 changed files with 279 additions and 30 deletions
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32
sql/sql_analyze_stmt.h
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@@ -158,6 +158,25 @@ public:
if (unlikely((tracker)->timed)) \
{ (tracker)->stop_tracking(thd); }
/*
Just a counter to increment one value. Wrapped in a class to be uniform
with other counters used by ANALYZE.
*/
class Counter_tracker
{
public:
Counter_tracker() : r_scans(0) {}
ha_rows r_scans;
inline void on_scan_init() { r_scans++; }
bool has_scans() const { return (r_scans != 0); }
ha_rows get_loops() const { return r_scans; }
};
/*
A class for collecting read statistics.
@@ -168,20 +187,16 @@ public:
It can be used to track reading from files, buffers, etc).
*/
class Table_access_tracker
class Table_access_tracker
{
public:
Table_access_tracker() :
r_scans(0), r_rows(0), /*r_rows_after_table_cond(0),*/
r_rows_after_where(0)
Table_access_tracker() : r_scans(0), r_rows(0), r_rows_after_where(0)
{}
ha_rows r_scans; /* How many scans were ran on this join_tab */
ha_rows r_scans; /* how many scans were ran on this join_tab */
ha_rows r_rows; /* How many rows we've got after that */
ha_rows r_rows_after_where; /* Rows after applying attached part of WHERE */
bool has_scans() const { return (r_scans != 0); }
ha_rows get_loops() const { return r_scans; }
double get_avg_rows() const
{
return r_scans
@@ -200,6 +215,9 @@ public:
inline void on_scan_init() { r_scans++; }
inline void on_record_read() { r_rows++; }
inline void on_record_after_where() { r_rows_after_where++; }
bool has_scans() const { return (r_scans != 0); }
ha_rows get_loops() const { return r_scans; }
};