accrue statistics to correct handler

MariaDB · Apr 23, 2024 · a11a101 · a11a101
1 parent 0940a96
commit a11a101
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Showing 3 changed files with 17 additions and 10 deletions.
diff --git a/sql/handler.cc b/sql/handler.cc
@@ -6995,6 +6995,7 @@ extern "C" check_result_t handler_index_cond_check(void* h_arg)
  check_result_t res;
 
  DEBUG_SYNC(thd, "handler_index_cond_check");
+ DBUG_ASSERT(h->handler_stats);
 
  enum thd_kill_levels killed= thd_kill_level(thd);
  if (unlikely(killed != THD_IS_NOT_KILLED))
@@ -7008,13 +7009,13 @@ extern "C" check_result_t handler_index_cond_check(void* h_arg)
  if (unlikely(h->end_range) && h->compare_key2(h->end_range) > 0)
  return CHECK_OUT_OF_RANGE;
  h->increment_statistics(&SSV::ha_icp_attempts);
- h->active_handler_stats.icp_attempts++;
+ h->handler_stats->icp_attempts++;
  res= CHECK_NEG;
  if (h->pushed_idx_cond->val_int())
  {
  res= CHECK_POS;
  h->fast_increment_statistics(&SSV::ha_icp_match);
- h->active_handler_stats.icp_match++;
+ h->handler_stats->icp_match++;
  }
  return res;
 }

diff --git a/sql/handler.h b/sql/handler.h
@@ -3211,7 +3211,13 @@ class handler :public Sql_alloc
 
  ha_rows estimation_rows_to_insert;
  handler *lookup_handler;
- /* Statistics for the query. Updated if handler_stats.in_use is set */
+ /*
+ Statistics for the query. Prefer to use the handler_stats pointer
+ below rather than this object directly as the clone() method will
+ modify how stats are accounted by adjusting the handler_stats
+ pointer. Referring to active_handler_stats directly will yield
+ surprising and possibly incorrect results.
+ */
  ha_handler_stats active_handler_stats;
  void set_handler_stats();
 public:

diff --git a/sql/sql_explain.cc b/sql/sql_explain.cc
@@ -1938,13 +1938,13 @@ static void trace_engine_stats(handler *file, Json_writer *writer)
 
 static void print_r_icp_filtered(handler *file, Json_writer *writer)
 {
- if (file && file->handler_stats && file->pushed_idx_cond)
- {
- ha_handler_stats *hs= file->handler_stats;
-  double r_icp_filtered = hs->icp_attempts ?
-  (double)(hs->icp_match) / (double)(hs->icp_attempts) : 1.0;
- writer->add_member("r_icp_filtered").add_double(r_icp_filtered * 100);
- }
+ if (!file || !file->handler_stats || !file->pushed_idx_cond)
+  return;
+
+ ha_handler_stats *hs= file->handler_stats;
+ double r_icp_filtered = hs->icp_attempts ?
+ (double)(hs->icp_match) / (double)(hs->icp_attempts) : 0.0;
+ writer->add_member("r_icp_filtered").add_double(r_icp_filtered * 100);
 }
 
 void Explain_table_access::print_explain_json(Explain_query *query,