Which statement is true about InnoDB persistent index statistics?
Which statement is true about InnoDB persistent index statistics?
Updating index statistics can be an I/O expensive operation because the process often involves reading a significant amount of data from storage to gather the necessary statistics, which can lead to high input/output operations, especially for large tables.
D is not about persistent indexed. E might be the answer but not sure
D is correct according to me.
C is correct
C is Correct https://dev.mysql.com/doc/refman/8.0/en/innodb-performance-optimizer-statistics.html
A. C is not correct because it mentions: "The innodb_stats_auto_recalc variable, which is enabled by default, controls whether statistics are calculated automatically when a table undergoes changes to more than 10% of its rows, not when new indexes are created.
D https://dev.mysql.com/doc/refman/8.0/en/innodb-parameters.html#sysvar_innodb_stats_persistent_sample_pages 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. Not C https://dev.mysql.com/doc/refman/8.0/en/innodb-parameters.html#sysvar_innodb_stats_auto_recalc This setting applies to tables created when the innodb_stats_persistent option is enabled.
A. Correct D. it has to be innodb_stats_transient_sample_pages for this to be correct