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  1. MariaDB Server
  2. MDEV-7681

Performance schema not fully configurable at runtime

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      Despite what MySQL manual says (http://dev.mysql.com/doc/refman/5.6/en/performance-schema-pre-filtering.html), some P_S instruments are not configurable at runtime. Even disabled, they keep collecting the data.

      There is an upstream documentation bug about it, https://bugs.mysql.com/bug.php?id=68097. Apparently MariaDB documentation should also be updated at some point.

      But on top of events common with the upstream version, MariaDB also has the same problem with Aria events. I don't know whether it's intentional. Noticed for

      wait/synch/cond/aria/SERVICE_THREAD_CONTROL::COND_control
      wait/synch/mutex/aria/SERVICE_THREAD_CONTROL::LOCK_control
      wait/synch/mutex/aria/SHARE::bitmap::bitmap_lock
      wait/synch/mutex/aria/SHARE::intern_lock
      wait/synch/mutex/aria/SHARE::close_lock

      A test might look somewhat like that (this variant doesn't necessarily reveal all affected instruments)

      select @@version;
      select @@performance_schema;
       
      use performance_schema;
       
      set global aria_checkpoint_interval = 1;
       
      update setup_consumers set enabled= 'YES';
      update setup_instruments set enabled= 'YES', timed= 'YES';
      update setup_objects set enabled= 'YES', timed= 'YES';
       
      create table test.t1 (i int);
      insert into test.t1 values (1),(2);
      drop table test.t1;
       
      select count(*) from events_waits_summary_global_by_event_name where count_star > 0 order by event_name;
       
      update setup_consumers set enabled= 'NO';
      update setup_instruments set enabled= 'NO', timed= 'NO';
      update setup_objects set enabled= 'NO', timed= 'NO';
       
      create table test.t1 (i int) engine=Aria;
      insert into test.t1 values (1),(2);
      drop table test.t1;
       
      truncate table events_waits_summary_global_by_event_name;
       
      select sleep(3);
      select * from events_waits_summary_global_by_event_name where count_star > 0 order by event_name;

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            Assignee:
            greenman Ian Gilfillan
            Reporter:
            elenst Elena Stepanova
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              Updated:

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