Bug #117809 Statistics update failed.
Submitted: 27 Mar 2025 13:06 Modified: 27 Mar 2025 19:49
Reporter: yangyang wang Email Updates:
Status: Verified Impact on me:
None 
Category:MySQL Server: InnoDB storage engine Severity:S5 (Performance)
Version: OS:Any
Assigned to: CPU Architecture:Any

[27 Mar 2025 13:06] yangyang wang 
Description:
For MySQL, when the number of tables is changed to more than 10%, statistics update is triggered and the table is sent to dict_stats_thread to update statistics. However, table objects in the memory are eliminated. If multiple tables are updated, statistics may fail to be updated for a long time.

void row_update_statistics_if_needed(dict_table_t *table) /*!< in: table */
{
  ib_uint64_t counter;
  ib_uint64_t n_rows;

  ...
  counter = table->stat_modified_counter++;
  n_rows = dict_table_get_n_rows(table);

  if (dict_stats_is_persistent_enabled(table)) {
    double recalc_pct = rds_recalc_persistent_stats_threshold_pct / 100;
    if (counter > (n_rows * recalc_pct) &&
        dict_stats_auto_recalc_is_enabled(table)) {
      dict_stats_recalc_pool_add(table);
      table->stat_modified_counter = 0;
    }
    return;
  }
The dict_table_t may be removed from the cache.

How to repeat:
1.create table
2.insert values
3.flush table
4.insert values
5.flush table
6.Check statistics.We can see that the statistics of the table are not updated.
[27 Mar 2025 19:49] MySQL Verification Team 
Hi,
I believe this is not a bug but a design decision but I'll pass this back to optimizer team to confirm.
[2 Jun 10:05] Øystein Grøvlen 
Posted by developer:
 
Update of statistics is the responsibility of the InnoDB engine.