Version sans cache

Mise en cache désactivé. Réglage défaut pour cette page : actif (code DEF204)
Si l'affichage est trop lent, vous pouvez désactiver le mode utilisateur pour visualiser la version en cache.

Rechercher dans le manuel MySQL

27.4.4.25 The statement _performance _analyzer () Procedure

Table des matières

Creates a report of the statements running on the server. The views are calculated based on the overall and/or delta activity.

This procedure disables binary logging during its execution by manipulating the session value of the sql_log_bin system variable. That is a restricted operation, so the procedure requires privileges sufficient to set restricted session variables. See Section 5.1.9.1, “System Variable Privileges”.

Parameters

  • in_action ENUM('snapshot', 'overall', 'delta', 'create_tmp', 'create_table', 'save', 'cleanup'): The action to take. These values are permitted:

    • snapshot: Store a snapshot. The default is to make a snapshot of the current content of the Performance Schema events_statements_summary_by_digest table. By setting in_table, this can be overwritten to copy the content of the specified table. The snapshot is stored in the sys schema tmp_digests temporary table.

    • overall: Generate an analysis based on the content of the table specified by in_table. For the overall analysis, in_table can be NOW() to use a fresh snapshot. This overwrites an existing snapshot. Use NULL for in_table to use the existing snapshot. If in_table is NULL and no snapshot exists, a new snapshot is created. The in_views parameter and the statement_performance_analyzer.limit configuration option affect the operation of this procedure.

    • delta: Generate a delta analysis. The delta is calculated between the reference table specified by in_table and the snapshot, which must exist. This action uses the sys schema tmp_digests_delta temporary table. The in_views parameter and the statement_performance_analyzer.limit configuration option affect the operation of this procedure.

    • create_table: Create a regular table suitable for storing the snapshot for later use (for example, for calculating deltas).

    • create_tmp: Create a temporary table suitable for storing the snapshot for later use (for example, for calculating deltas).

    • save: Save the snapshot in the table specified by in_table. The table must exist and have the correct structure. If no snapshot exists, a new snapshot is created.

    • cleanup: Remove the temporary tables used for the snapshot and delta.

  • in_table VARCHAR(129): The table parameter used for some of the actions specified by the in_action parameter. Use the format db_name.tbl_name or tbl_name without using any backtick (`) identifier-quoting characters. Periods (.) are not supported in database and table names.

    The meaning of the in_table value for each in_action value is detailed in the individual in_action value descriptions.

  • in_views SET ('with_runtimes_in_95th_percentile', 'analysis', 'with_errors_or_warnings', 'with_full_table_scans', 'with_sorting', 'with_temp_tables', 'custom'): Which views to include. This parameter is a SET value, so it can contain multiple view names, separated by commas. The default is to include all views except custom. The following values are permitted:

Table des matières Haut

Configuration Options

statement_performance_analyzer() operation can be modified using the following configuration options or their corresponding user-defined variables (see Section 27.4.2.1, “The sys_config Table”):

  • debug, @sys.debug

    If this option is ON, produce debugging output. The default is OFF.

  • statement_performance_analyzer.limit, @sys.statement_performance_analyzer.limit

    The maximum number of rows to return for views that have no built-in limit. The default is 100.

  • statement_performance_analyzer.view, @sys.statement_performance_analyzer.view

    The custom query or view to be used. If the option value contains a space, it is interpreted as a query. Otherwise, it must be the name of an existing view that queries the Performance Schema events_statements_summary_by_digest table. There cannot be any LIMIT clause in the query or view definition if the statement_performance_analyzer.limit configuration option is greater than 0. If specifying a view, use the same format as for the in_table parameter. The default is NULL (no custom view defined).

To create a report with the queries in the 95th percentile since the last truncation of events_statements_summary_by_digest and with a one-minute delta period:

  1. Create a temporary table to store the initial snapshot.

  2. Create the initial snapshot.

  3. Save the initial snapshot in the temporary table.

  4. Wait one minute.

  5. Create a new snapshot.

  6. Perform analysis based on the new snapshot.

  7. Perform analysis based on the delta between the initial and new snapshots.

  1. mysql> CALL sys.statement_performance_analyzer('create_tmp', 'mydb.tmp_digests_ini', NULL);
  2. Query OK, 0 rows affected (0.08 sec)
  3.  
  4. mysql> CALL sys.statement_performance_analyzer('snapshot', NULL, NULL);
  5. Query OK, 0 rows affected (0.02 sec)
  6.  
  7. mysql> CALL sys.statement_performance_analyzer('save', 'mydb.tmp_digests_ini', NULL);
  8. Query OK, 0 rows affected (0.00 sec)
  9.  
  10. mysql> DO SLEEP(60);
  11. Query OK, 0 rows affected (1 min 0.00 sec)
  12.  
  13. mysql> CALL sys.statement_performance_analyzer('snapshot', NULL, NULL);
  14. Query OK, 0 rows affected (0.02 sec)
  15.  
  16. mysql> CALL sys.statement_performance_analyzer('overall', NULL, 'with_runtimes_in_95th_percentile');
  17. +-----------------------------------------+
  18. | Next Output                             |
  19. +-----------------------------------------+
  20. | Queries with Runtime in 95th Percentile |
  21. +-----------------------------------------+
  22. 1 row in set (0.05 sec)
  23.  
  24. ...
  25.  
  26. mysql> CALL sys.statement_performance_analyzer('delta', 'mydb.tmp_digests_ini', 'with_runtimes_in_95th_percentile');
  27. +-----------------------------------------+
  28. | Next Output                             |
  29. +-----------------------------------------+
  30. | Queries with Runtime in 95th Percentile |
  31. +-----------------------------------------+
  32. 1 row in set (0.03 sec)
  33.  
  34. ...

Create an overall report of the 95th percentile queries and the top 10 queries with full table scans:

  1. mysql> CALL sys.statement_performance_analyzer('snapshot', NULL, NULL);
  2. Query OK, 0 rows affected (0.01 sec)                                
  3.  
  4. mysql> SET @sys.statement_performance_analyzer.limit = 10;
  5. Query OK, 0 rows affected (0.00 sec)        
  6.  
  7. mysql> CALL sys.statement_performance_analyzer('overall', NULL, 'with_runtimes_in_95th_percentile,with_full_table_scans');
  8. +-----------------------------------------+
  9. | Next Output                             |
  10. +-----------------------------------------+
  11. | Queries with Runtime in 95th Percentile |
  12. +-----------------------------------------+
  13. 1 row in set (0.01 sec)
  14.  
  15. ...
  16.  
  17. +-------------------------------------+
  18. | Next Output                         |
  19. +-------------------------------------+
  20. | Top 10 Queries with Full Table Scan |
  21. +-------------------------------------+
  22. 1 row in set (0.09 sec)
  23.  
  24. ...

Use a custom view showing the top 10 queries sorted by total execution time, refreshing the view every minute using the watch command in Linux:

  1. mysql> CREATE OR REPLACE VIEW mydb.my_statements AS
  2.        SELECT sys.format_statement(DIGEST_TEXT) AS query,
  3.               SCHEMA_NAME AS db,
  4.               COUNT_STAR AS exec_count,
  5.               sys.format_time(SUM_TIMER_WAIT) AS total_latency,
  6.               sys.format_time(AVG_TIMER_WAIT) AS avg_latency,
  7.               ROUND(IFNULL(SUM_ROWS_SENT / NULLIF(COUNT_STAR, 0), 0)) AS rows_sent_avg,
  8.               ROUND(IFNULL(SUM_ROWS_EXAMINED / NULLIF(COUNT_STAR, 0), 0)) AS rows_examined_avg,
  9.               ROUND(IFNULL(SUM_ROWS_AFFECTED / NULLIF(COUNT_STAR, 0), 0)) AS rows_affected_avg,
  10.               DIGEST AS digest
  11.          FROM performance_schema.events_statements_summary_by_digest
  12.        ORDER BY SUM_TIMER_WAIT DESC;
  13. Query OK, 0 rows affected (0.10 sec)
  14.  
  15. mysql> CALL sys.statement_performance_analyzer('create_table', 'mydb.digests_prev', NULL);
  16. Query OK, 0 rows affected (0.10 sec)
  17.  
  18. shell> watch -n 60 "mysql sys --table -e \"
  19. > SET @sys.statement_performance_analyzer.view = 'mydb.my_statements';
  20. > SET @sys.statement_performance_analyzer.limit = 10;
  21. > CALL statement_performance_analyzer('snapshot', NULL, NULL);
  22. > CALL statement_performance_analyzer('delta', 'mydb.digests_prev', 'custom');
  23. > CALL statement_performance_analyzer('save', 'mydb.digests_prev', NULL);
  24. > \""
  25.  
  26. Every 60.0s: mysql sys --table -e "        ...  Mon Dec 22 10:58:51 2014
  27.  
  28. +----------------------------------+
  29. | Next Output                      |
  30. +----------------------------------+
  31. | Top 10 Queries Using Custom View |
  32. +----------------------------------+
  33. +-------------------+-------+------------+---------------+-------------+---------------+-------------------+-------------------+----------------------------------+
  34. | query             | db    | exec_count | total_latency | avg_latency | rows_sent_avg | rows_examined_avg | rows_affected_avg | digest                           |
  35. +-------------------+-------+------------+---------------+-------------+---------------+-------------------+-------------------+----------------------------------+
  36. ...

Rechercher dans le manuel MySQL

Traduction non disponible

Le manuel MySQL n'est pas encore traduit en français sur l'infobrol. Seule la version anglaise est disponible pour l'instant.

Document créé le 26/06/2006, dernière modification le 26/10/2018
Source du document imprimé : https://www.gaudry.be/mysql-rf-sys-statement-performance-analyzer.html

L'infobrol est un site personnel dont le contenu n'engage que moi. Le texte est mis à disposition sous licence CreativeCommons(BY-NC-SA). Plus d'info sur les conditions d'utilisation et sur l'auteur.

Références

  1. Consulter le document html Langue du document :en Manuel MySQL : https://dev.mysql.com/

Ces références et liens indiquent des documents consultés lors de la rédaction de cette page, ou qui peuvent apporter un complément d'information, mais les auteurs de ces sources ne peuvent être tenus responsables du contenu de cette page.
L'auteur de ce site est seul responsable de la manière dont sont présentés ici les différents concepts, et des libertés qui sont prises avec les ouvrages de référence. N'oubliez pas que vous devez croiser les informations de sources multiples afin de diminuer les risques d'erreurs.

Table des matières Haut