InnoDB System Variables Command-Line Format --innodb-stats-persistent-sample- pages=# System Variable innodb_stats_persistent_sample_pages Scope Global Dynamic Yes SET_VAR  Hint Applies No Type Integer Default Value 20 Command-Line Format --innodb-stats-transient-sample- pages=# System Variable innodb_stats_transient_sample_pages Scope Global Dynamic Yes SET_VAR  Hint Applies No Type Integer Default Value 8 The number of index pages to sample when estimating cardinality and other statistics for an indexed column, such as those calculated by  ANALYZE TABLE . The default value is 8. Increasing the value improves the accuracy of index statistics, which can improve the query execution plan, at the expense of increased I/O when opening an  InnoDB  table or recalculating statistics. For more information, see Section 15.8.10.2, “Configuring Non-Persistent Optimizer Statistics Parameters” . The number of index pages to sample when estimating cardinality and other statistics for an indexed column, such as those calculated by  ANALYZE TABLE . Increasing the value improves the accuracy of index statistics, which can improve the query execution plan, at the expense of increased I/O during the execution of  ANALYZE TABLE  for an  InnoDB  table. For more information, see Section 15.8.10.1, “Configuring Persistent Optimizer Statistics Parameters” . Setting a high value for  innodb_stats_persistent_sample_pages  could result in lengthy  ANALYZE TABLE  execution time. To estimate the number of database pages accessed by  ANALYZE TABLE , see Section 15.8.10.3, “Estimating ANALYZE TABLE Complexity for InnoDB Tables” . Note innodb_stats_persistent_sample_pages  only applies when  innodb_stats_persistent is enabled for a table; when  innodb_stats_persistent  is disabled, innodb_stats_transient_sample_pages  applies instead. Setting a high value for  innodb_stats_transient_sample_pages  could result in lengthy  ANALYZE TABLE  execution time. To estimate the number Note 3285 • innodb_stats_persistent_sample_pages • innodb_stats_transient_sample_pages