Rechercher dans le manuel MySQL
27.4.4.25 The statement _performance _analyzer () Procedure
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 Schemaevents_statements_summary_by_digest
table. By settingin_table
, this can be overwritten to copy the content of the specified table. The snapshot is stored in thesys
schematmp_digests
temporary table.overall
: Generate an analysis based on the content of the table specified byin_table
. For the overall analysis,in_table
can beNOW()
to use a fresh snapshot. This overwrites an existing snapshot. UseNULL
forin_table
to use the existing snapshot. Ifin_table
isNULL
and no snapshot exists, a new snapshot is created. Thein_views
parameter and thestatement_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 byin_table
and the snapshot, which must exist. This action uses thesys
schematmp_digests_delta
temporary table. Thein_views
parameter and thestatement_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 byin_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 thein_action
parameter. Use the formatdb_name.tbl_name
ortbl_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 eachin_action
value is detailed in the individualin_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 aSET
value, so it can contain multiple view names, separated by commas. The default is to include all views exceptcustom
. The following values are permitted:with_runtimes_in_95th_percentile
: Use thestatements_with_runtimes_in_95th_percentile
view.analysis
: Use thestatement_analysis
view.with_errors_or_warnings
: Use thestatements_with_errors_or_warnings
view.with_full_table_scans
: Use thestatements_with_full_table_scans
view.with_sorting
: Use thestatements_with_sorting
view.with_temp_tables
: Use thestatements_with_temp_tables
view.custom
: Use a custom view. This view must be specified using thestatement_performance_analyzer.view
configuration option to name a query or an existing view.
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 isOFF
.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 anyLIMIT
clause in the query or view definition if thestatement_performance_analyzer.limit
configuration option is greater than 0. If specifying a view, use the same format as for thein_table
parameter. The default isNULL
(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:
Create a temporary table to store the initial snapshot.
Create the initial snapshot.
Save the initial snapshot in the temporary table.
Wait one minute.
Create a new snapshot.
Perform analysis based on the new snapshot.
Perform analysis based on the delta between the initial and new snapshots.
- Query OK, 0 rows affected (0.08 sec)
- Query OK, 0 rows affected (0.02 sec)
- Query OK, 0 rows affected (0.00 sec)
- Query OK, 0 rows affected (0.02 sec)
- +-----------------------------------------+
- +-----------------------------------------+
- +-----------------------------------------+
- ...
- mysql> CALL sys.statement_performance_analyzer('delta', 'mydb.tmp_digests_ini', 'with_runtimes_in_95th_percentile');
- +-----------------------------------------+
- +-----------------------------------------+
- +-----------------------------------------+
- ...
Create an overall report of the 95th percentile queries and the top 10 queries with full table scans:
- Query OK, 0 rows affected (0.01 sec)
- Query OK, 0 rows affected (0.00 sec)
- +-----------------------------------------+
- +-----------------------------------------+
- +-----------------------------------------+
- ...
- +-------------------------------------+
- +-------------------------------------+
- +-------------------------------------+
- ...
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:
- SCHEMA_NAME AS db,
- COUNT_STAR AS exec_count,
- DIGEST AS digest
- FROM performance_schema.events_statements_summary_by_digest
- Query OK, 0 rows affected (0.10 sec)
- Query OK, 0 rows affected (0.10 sec)
- shell> watch -n 60 "mysql sys --table -e \"
- > SET @sys.statement_performance_analyzer.view = 'mydb.my_statements';
- > SET @sys.statement_performance_analyzer.limit = 10;
- > CALL statement_performance_analyzer('snapshot', NULL, NULL);
- > CALL statement_performance_analyzer('delta', 'mydb.digests_prev', 'custom');
- > CALL statement_performance_analyzer('save', 'mydb.digests_prev', NULL);
- > \""
- +----------------------------------+
- | Next Output |
- +----------------------------------+
- | Top 10 Queries Using Custom View |
- +----------------------------------+
- +-------------------+-------+------------+---------------+-------------+---------------+-------------------+-------------------+----------------------------------+
- | query | db | exec_count | total_latency | avg_latency | rows_sent_avg | rows_examined_avg | rows_affected_avg | digest |
- +-------------------+-------+------------+---------------+-------------+---------------+-------------------+-------------------+----------------------------------+
- ...
Document created the 26/06/2006, last modified the 26/10/2018
Source of the printed document:https://www.gaudry.be/en/mysql-rf-sys-statement-performance-analyzer.html
The infobrol is a personal site whose content is my sole responsibility. The text is available under CreativeCommons license (BY-NC-SA). More info on the terms of use and the author.
References
These references and links indicate documents consulted during the writing of this page, or which may provide additional information, but the authors of these sources can not be held responsible for the content of this page.
The author This site is solely responsible for the way in which the various concepts, and the freedoms that are taken with the reference works, are presented here. Remember that you must cross multiple source information to reduce the risk of errors.