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  1. MariaDB Server
  2. MDEV-18892

Regression in slow log and admin statements

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      Description

      There is a regression caused by MDEV-18333.

      As of this commit before MDEV-18333:

      commit f2e1451740d417f1c9ea8626d937fbcacc91bb55
      Merge: e39d6e0 2d34713
      Author: Oleksandr Byelkin <sanja@mariadb.com>
      Date:   Fri Mar 1 15:52:06 2019 +0100
      

      The following script

      FLUSH SLOW LOGS;
      SET @@GLOBAL.slow_query_log=ON;
      SET @@GLOBAL.log_output='TABLE';
      SET @@SESSION.slow_query_log=ON;
      SET @@SESSION.long_query_time=0.000001;
       
      SET @@GLOBAL.log_slow_admin_statements=OFF;
      SET log_slow_filter=DEFAULT;
      TRUNCATE TABLE mysql.slow_log;
      CREATE TABLE t1 (a INT);
      INSERT INTO t1 VALUES (1),(2),(3),(4);
      ALTER TABLE t1 ADD b INT;
      PREPARE stmt FROM 'ALTER TABLE t1 ADD c INT';
      EXECUTE stmt;
      DEALLOCATE PREPARE stmt;
      DROP TABLE t1;
      SELECT db, user_host, sql_text FROM mysql.slow_log WHERE sql_text NOT LIKE '%debug_dbug%';
      

      produced this output:

      +------+---------------------------+----------------------------------------------+
      | db   | user_host                 | sql_text                                     |
      +------+---------------------------+----------------------------------------------+
      | test | root[root] @ localhost [] | TRUNCATE TABLE mysql.slow_log                |
      | test | root[root] @ localhost [] | CREATE TABLE t1 (a INT)                      |
      | test | root[root] @ localhost [] | INSERT INTO t1 VALUES (1),(2),(3),(4)        |
      | test | root[root] @ localhost [] | PREPARE stmt FROM 'ALTER TABLE t1 ADD c INT' |
      | test | root[root] @ localhost [] | DEALLOCATE PREPARE stmt                      |
      | test | root[root] @ localhost [] | DROP TABLE t1                                |
      +------+---------------------------+----------------------------------------------+
      

      As of this later commit (which includes MDEV-18333):

      commit ea52ecbc103b1424cf0b6f8faf990676b2b57a63
      Merge: 2a2ab12 149b754
      Author: Sergey Vojtovich <svoj@mariadb.org>
      Date:   Mon Mar 11 22:50:24 2019 +0400
      

      the same script returns a different output:

      +------+---------------------------+----------------------------------------------+
      | db   | user_host                 | sql_text                                     |
      +------+---------------------------+----------------------------------------------+
      | test | root[root] @ localhost [] | TRUNCATE TABLE mysql.slow_log                |
      | test | root[root] @ localhost [] | CREATE TABLE t1 (a INT)                      |
      | test | root[root] @ localhost [] | INSERT INTO t1 VALUES (1),(2),(3),(4)        |
      | test | root[root] @ localhost [] | PREPARE stmt FROM 'ALTER TABLE t1 ADD c INT' |
      | test | root[root] @ localhost [] | ALTER TABLE t1 ADD c INT                     |
      | test | root[root] @ localhost [] | DEALLOCATE PREPARE stmt                      |
      | test | root[root] @ localhost [] | DROP TABLE t1                                |
      +------+---------------------------+----------------------------------------------+
      

      Notice, before MDEV-18333, non of the ALTER statements appeared in the slow log.

      With MDEV-18333:

      • the directly executed ALTER is not in the slow log (correct)
      • the prepared ALTER is in the log (wrong)

      The served does not respect the log_slow_admin_statements setting with prepared statements any more.

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              Assignee:
              bar Alexander Barkov
              Reporter:
              bar Alexander Barkov
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                Created:
                Updated:
                Resolved: