mysql sys schema oow 2014 - files.meetup.comfiles.meetup.com/107575/chicago_mysql_meetup_slides_20150422.… · MySQL sys views • Reference set of views solving various administrator

Copyright © 2014, Oracle and/or its affiliates. All rights reserved. |

The MySQL SYS Schema

Mark Matthews Consulting Member, Technical Staff MySQL Enterprise Tools, Oracle



Safe Harbor Statement

The following is intended to outline our general product direction. It is intended for information purposes only, and may not be incorporated into any contract. It is not a commitment to deliver any material, code, or functionality, and should not be relied upon in making purchasing decisions. The development, release, and timing of any features or functionality described for Oracle’s products remains at the sole discretion of Oracle.


Program Agenda

PERFORMANCE_SCHEMA in a few slides

Introduction to the MySQL sys schema

Installation

Summary Views

Procedures and Functions

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Program Agenda



Installation

Summary Views


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PERFORMANCE_SCHEMA

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• MySQLd-wide timing/tracing/profiling by Marc Alf, Chris Powers and Mayank Prasad

• Dynamically configurable (what, resolution)

• Non-persistent storage engine, data and configuration in tables

• 5.6 - 554 instrumentation points (including file i/o, statements)

• 5.7 - 983 (so far) instrumentation points (transactions, mdl, stored programs, memory usage, replication, user and status variables)

Copyright © 2014, Oracle and/or its affiliates. All rights reserved. | 6


Program Agenda



Installation

Summary Views


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• Originally called “ps_helper”

• A collection of views, procedures and functions, designed to help DBA, Developer, and Ops teams • Implements many of the common day to day DBA and Developer

debugging and tuning use cases


Why the sys schema?

• Performance Schema exposes a huge amount of data, that can be sliced and diced in many ways • Many of its tables can implement many different use cases when

looking at the raw data • The sys schema layers on top the (sometimes complex) queries in

to a packaged set of easy to use views • The sys schema also layers on a number of functions and

procedures that help format, and record the raw data


Program Agenda



Installation

Summary Views


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Installation from the command line

• $ git clone https://github.com/MarkLeith/mysql-sys.git /tmp/sys

• $ cd /tmp/sys • $ mysql -u user -p < sys_<version>.sql

<version> can be 56 or 57, for 5.6 and 5.7 respectively

https://github.com/MarkLeith/mysql-sys.git


Installation from MySQL Workbench 6.1+


select * from sys.version;

+-------------+---------------+

| sys_version | mysql_version |

+-------------+---------------+

| 1.1.0 | 5.6.17 |

+-------------+---------------+

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Checking sys is loadedselect *

from sys.schema_object_overview

where db = 'sys';

+-----+-------------+-------+

| db | object_type | count |

+-----+-------------+-------+

| sys | VIEW | 78 |

| sys | PROCEDURE | 22 |

| sys | FUNCTION | 11 |

+-----+-------------+-------+


Or simply use MySQL-5.7

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The “sys” schema was integrated into MySQL 5.7 as of 5.7.7!


Program Agenda



Installation

Summary Views


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MySQL sys views

• Reference set of views solving various administrator use cases • Simple views, create/copy your own, sys is not “locked down”

• Build upon both performance_schema and INFORMATION_SCHEMA • Both formatted and raw views are available • All raw views are prefixed with x$ • Raw views are there for tools to poll

• Formatted views are for humans and the command line


• High level user/host overviews • Breakdowns by: • IO usage • Stages • Statement details

• Following show users only

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User / Host Summary Views

user_summary user_summary_by_file_io user_summary_by_file_io_type user_summary_by_stages user_summary_by_statement_latency user_summary_by_statement_type host_summary host_summary_by_file_io host_summary_by_file_io_type host_summary_by_stages host_summary_by_statement_latency host_summary_by_statement_type


user_summary viewmysql> select * from user_summary\G*************************** 1. row *************************** user: mark statements: 3072 statement_latency: 1.77 s statement_avg_latency: 575.29 us table_scans: 7 file_ios: 20043 file_io_latency: 346.79 ms current_connections: 1 total_connections: 1 unique_hosts: 1 current_memory: 515.81 KiBtotal_memory_allocated: 30.69 MiB

MySQL 5.7.4+


user_summary_by_file_io_type view

mysql> select * from user_summary_by_file_io_type;+------+--------------------------------------+---------+-------------+-------------+| user | event_name | total | latency | max_latency |+------+--------------------------------------+---------+-------------+-------------+| mark | wait/io/file/myisam/dfile | 19540 | 215.20 ms | 120.79 ms || mark | wait/io/file/myisam/kfile | 501 | 131.58 ms | 57.74 ms || mark | wait/io/file/sql/dbopt | 2 | 17.29 us | 9.17 us || root | wait/io/file/innodb/innodb_log_file | 2079432 | 00:28:27.62 | 1.30 s || root | wait/io/file/myisam/kfile | 5195927 | 00:17:07.33 | 1.17 s || root | wait/io/file/myisam/dfile | 1533813 | 00:07:27.59 | 1.18 s || root | wait/io/file/sql/binlog | 3517008 | 00:03:07.34 | 1.42 s || root | wait/io/file/innodb/innodb_data_file | 20720 | 00:02:37.81 | 492.23 ms || root | wait/io/file/sql/FRM | 41412 | 3.17 s | 80.43 ms || root | wait/io/file/sql/dbopt | 110993 | 1.23 s | 63.27 ms |


user_summary_by_statement_latency view

mysql> select * from user_summary_by_statement_latency\G*************************** 1. row *************************** user: mark total: 176total_latency: 1.26 s max_latency: 583.33 ms lock_latency: 216.95 ms rows_sent: 311rows_examined: 307rows_affected: 0 full_scans: 7


user_summary_by_statement_type view

mysql> select * from user_summary_by_statement_type\G*************************** 1. row *************************** user: mark statement: commit total: 2463190total_latency: 13.33h max_latency: 12.18 s lock_latency: 0 ps rows_sent: 0rows_examined: 0rows_affected: 0 full_scans: 0


• IO by current threads • Global summaries by file and

class, aggregating by bytes or latency • Stream of last file IO events in

raw form

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IO Summary Views

io_by_thread_by_latency io_global_by_file_by_bytes io_global_by_file_by_latency io_global_by_wait_by_bytes io_global_by_wait_by_latency


io_by_thread_by_latency viewmysql> select * from io_by_thread_by_latency\G*************************** 1. row *************************** user: main total: 1193 total_latency: 136.45 ms min_latency: 731.38 ns avg_latency: 269.99 us max_latency: 20.72 ms thread_id: 1processlist_id: NULL*************************** 2. row *************************** user: root@localhost total: 533 total_latency: 53.81 ms min_latency: 780.39 ns avg_latency: 8.41 ms max_latency: 25.06 ms thread_id: 23processlist_id: 4


io_global_by_file_by_latency view

mysql> select * from io_global_by_file_by_latency limit 1\G*************************** 1. row *************************** file: @@datadir/ibdata1 total: 1395714total_latency: 00:28:53.06 count_read: 1006 read_latency: 4.51 s count_write: 1326529write_latency: 33.39 s count_misc: 68179 misc_latency: 00:28:15.16


latest_file_io viewmysql> select * from latest_file_io;+-----------------------------+----------------------------------+-----------+-----------+-----------+| thread | file | latency | operation | requested |+-----------------------------+----------------------------------+-----------+-----------+-----------+| root@localhost:63153:179371 | @@datadir/ib_logfile1 | 7.16 us | lock | NULL || root@localhost:63153:179371 | @@datadir/ib_logfile1 | 6.16 us | write | 1.50 KiB || root@localhost:63153:179371 | @@datadir/ib_logfile1 | 14.36 ms | sync | NULL || root@localhost:63153:179371 | @@datadir/cerberus-bin.000012 | 28.25 us | write | 905 bytes || root@localhost:63177:179394 | @@datadir/ib_logfile1 | 15.25 us | write | 1.00 KiB || root@localhost:57487:3 | @@datadir/cerberus-bin.000012 | 32.12 us | read | 905 bytes || root@localhost:63177:179394 | @@datadir/ib_logfile1 | 6.65 us | write | 1.00 KiB || root@localhost:63177:179394 | @@datadir/ib_logfile1 | 213.32 us | sync | NULL || root@localhost:63177:179394 | @@datadir/ib_logfile1 | 17.27 us | write | 1.00 KiB || root@localhost:63177:179394 | @@datadir/ib_logfile1 | 286.01 us | sync | NULL || root@localhost:63177:179394 | @@datadir/cerberus-bin.000012 | 18.77 us | write | 601 bytes || root@localhost:57487:3 | @@datadir/cerberus-bin.000012 | 7.55 us | read | 601 bytes || root@localhost:63177:179394 | @@datadir/ib_logfile1 | 10.67 us | write | 1.00 KiB || root@localhost:63177:179394 | @@datadir/ib_logfile1 | 200.28 us | sync | NULL || root@localhost:63177:179394 | @@datadir/cerberus-bin.000012 | 12.91 us | write | 601 bytes || root@localhost:57487:3 | @@datadir/cerberus-bin.000012 | 6.47 us | read | 601 bytes || root@localhost:63177:179394 | @@datadir/ib_logfile1 | 9.22 us | write | 1.50 KiB |……


• Object overview • Table usage statistics • Index usage statistics • Following show users only

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Schema Analysis Views

schema_index_statistics schema_object_overview schema_table_statistics schema_table_statistics_with_buffer schema_tables_with_full_table_scans schema_unused_indexes


schema_table_statistics viewmysql> select * from schema_table_statistics limit 1\G*************************** 1. row *************************** table_schema: mem__quan table_name: normalized_statements_by_server_by_schema_data total_latency: 00:55:07.80 rows_fetched: 239685 fetch_latency: 17.10 s rows_inserted: 1102895 insert_latency: 00:52:18.10 rows_updated: 55910 update_latency: 00:02:28.62 rows_deleted: 17899 delete_latency: 3.98 s

io_read_requests: 20639 io_read: 324.94 MiB io_read_latency: 00:03:04.10io_write_requests: 1965973 io_write: 40.36 GiB io_write_latency: 25.46 s io_misc_requests: 18217 io_misc_latency: 00:14:06.02


schema_index_statistics view

mysql> select * from schema_index_statistics limit 1\G*************************** 1. row *************************** table_schema: mem__inventory table_name: mysqlconnectionconfiguration index_name: PRIMARY rows_selected: 131399select_latency: 00:07:05.03 rows_inserted: 0insert_latency: 0 ps rows_updated: 41608update_latency: 21.96 s rows_deleted: 0delete_latency: 0 ps


schema_tables_with_full_table_scans view

mysql> select * from schema_tables_with_full_table_scans limit 10;+--------------------+--------------------------------+-------------------+-----------+| object_schema | object_name | rows_full_scanned | latency |+--------------------+--------------------------------+-------------------+-----------+| mem30__instruments | fsstatistics | 10207042 | 13.10 s || mem30__instruments | preparedstatementapidata | 436428 | 973.27 ms || mem30__instruments | mysqlprocessactivity | 411702 | 282.07 ms || mem30__instruments | querycachequeriesincachedata | 374011 | 767.15 ms || mem30__instruments | rowaccessesdata | 322321 | 1.55 s || mem30__instruments | connectionsmaxdata | 301242 | 857.63 ms || mem30__instruments | innodbdatadictionarymemorydata | 292564 | 495.38 ms || mem30__instruments | innodbbufferpooldata | 277112 | 1.95 s || mem30__instruments | avgrowaccessesdata | 269236 | 1.25 s || mem30__instruments | innodbrowdetailsdata | 248208 | 653.25 ms |+--------------------+--------------------------------+-------------------+-----------+


schema_unused_indexes view

mysql> select * from schema_unused_indexes limit 10;+--------------------+-----------------------------------+--------------------+| object_schema | object_name | index_name |+--------------------+-----------------------------------+--------------------+| mem30__bean_config | plists | path || mem30__config | group_selections | name || mem30__config | notification_groups | name || mem30__config | user_form_defaults | FKC1AEF1F9E7EE2CFB || mem30__enterprise | whats_new_entries | entryId || mem30__events | action_logs | policyId || mem30__events | action_logs | eventId || mem30__events | action_logs | ts || mem30__events | advisor_scopes_advisorcategoryids | FKF0CB0DB962CAB4 || mem30__events | advisor_scopes_advisorclassids | FK650AF1BF962CAB4 |+--------------------+-----------------------------------+--------------------+

You should ensure you have representative time frame before taking any actions!


• Wait summaries by class • Wait details per: • User • Host • Globally

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Wait Analysis Views

wait_classes_global_by_avg_latency wait_classes_global_by_latency waits_by_host_by_latency waits_by_user_by_latency waits_global_by_latency


waits_global_by_latency view

mysql> select * from waits_global_by_latency limit 10;+--------------------------------------+----------+---------------+-------------+-------------+| events | total | total_latency | avg_latency | max_latency |+--------------------------------------+----------+---------------+-------------+-------------+| wait/io/table/sql/handler | 24196659 | 1.75h | 259.72 us | 2.29 s || wait/io/file/innodb/innodb_data_file | 5964255 | 1.36h | 822.01 us | 1.49 s || wait/io/file/innodb/innodb_log_file | 2272647 | 00:36:41.37 | 968.64 us | 1.30 s || wait/io/file/myisam/kfile | 5463587 | 00:18:14.16 | 200.26 us | 1.17 s || wait/io/file/myisam/dfile | 1715187 | 00:08:00.18 | 279.96 us | 1.18 s || wait/io/file/sql/binlog | 3722079 | 00:03:23.71 | 54.73 us | 1.42 s || wait/lock/table/sql/handler | 10074274 | 00:01:56.63 | 11.58 us | 186.90 ms || wait/io/socket/sql/client_connection | 3879827 | 25.36 s | 6.54 us | 219.25 ms || wait/io/file/sql/FRM | 43994 | 3.27 s | 74.35 us | 80.43 ms || wait/io/file/sql/dbopt | 116765 | 1.29 s | 11.03 us | 63.27 ms |+--------------------------------------+----------+---------------+-------------+-------------+

InnoDB only instance, this MyISAM IO is all temporary tables, focus tuning there!


waits_by_user_by_latency view

mysql> select * from waits_by_user_by_latency;+------+--------------------------------------+----------+---------------+-------------+-------------+| user | event | total | total_latency | avg_latency | max_latency |+------+--------------------------------------+----------+---------------+-------------+-------------+| mark | wait/io/file/myisam/dfile | 19540 | 215.20 ms | 11.01 us | 120.79 ms || mark | wait/io/file/myisam/kfile | 501 | 131.58 ms | 262.63 us | 57.74 ms || mark | wait/io/file/sql/dbopt | 2 | 17.29 us | 8.64 us | 9.17 us || root | wait/io/table/sql/handler | 24189319 | 1.74h | 258.77 us | 2.29 s || root | wait/io/file/innodb/innodb_log_file | 2162650 | 00:30:52.87 | 856.76 us | 1.30 s || root | wait/io/file/myisam/kfile | 5460992 | 00:18:12.83 | 200.11 us | 1.17 s || root | wait/io/file/myisam/dfile | 1694624 | 00:07:59.50 | 282.95 us | 1.18 s || root | wait/io/file/sql/binlog | 3711637 | 00:03:23.16 | 54.74 us | 1.42 s || root | wait/io/file/innodb/innodb_data_file | 22577 | 00:03:05.73 | 8.23 ms | 492.23 ms || root | wait/lock/table/sql/handler | 10069000 | 00:01:56.59 | 11.58 us | 186.90 ms |……

root is doing the most temporary table IO


• Statement overview • Find statements by: • Those with errors • Those with full table scans • Those creating temp tables • Those that cause sorting • With latency in 95th %ile

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Statement Analysis Views

statement_analysis statements_with_errors_or_warnings statements_with_full_table_scans statements_with_runtimes_in_95th_percentile statements_with_sorting statements_with_temp_tables


statement_analysis viewmysql> select * from statement_analysis limit 2\G*************************** 1. row *************************** query: INSERT INTO `mem30__quan` . `n ... nDuration` = IF ( VALUES ( ... db: mem full_scan: exec_count: 4657 err_count: 0 warn_count: 0 total_latency: 00:03:57.40 max_latency: 10.54 s avg_latency: 50.98 ms lock_latency: 00:03:00.93 rows_sent: 0 rows_sent_avg: 0 rows_examined: 0rows_examined_avg: 0 rows_affected: 4794rows_affected_avg: 1

tmp_tables: 0 tmp_disk_tables: 0 rows_sorted: 0sort_merge_passes: 0 digest: b98bfe333642e8e4e72c73515810d865 first_seen: 2014-09-24 11:27:01 last_seen: 2014-09-24 11:53:00


statements_with_errors_or_warnings view

mysql> select * from statements_with_errors_or_warnings limit 1\G*************************** 1. row *************************** query: CREATE TEMPORARY TABLE IF NOT ... _logs` ( `id` INT8 NOT NULL ) db: mem exec_count: 1725 errors: 1725 error_pct: 100.0000 warnings: 0warning_pct: 0.0000 first_seen: 2014-05-20 10:42:32 last_seen: 2014-05-21 18:39:22 digest: 51fb979dbc3910a6294c7cdabd7839c3


statements_with_temp_tables view

mysql> select * from statements_with_temp_tables limit 1\G*************************** 1. row *************************** query: SELECT * FROM ( SELECT `digest ... ` , `sum_no_index_used` AS ... db: mysql exec_count: 68 total_latency: 2.31 s memory_tmp_tables: 476 disk_tmp_tables: 204avg_tmp_tables_per_query: 7 tmp_tables_to_disk_pct: 43 first_seen: 2014-09-24 11:26:18 last_seen: 2014-09-24 12:33:00 digest: 50761c6a1818824328745d8a136b9ed6


statements_with_full_table_scans viewmysql> select * from statements_with_full_table_scans limit 1\G*************************** 1. row *************************** query: SELECT `pojotimese0_` . `id` A ... ty_timeseries` `pojotimese0_` db: mem exec_count: 1 total_latency: 940.89 us no_index_used_count: 1no_good_index_used_count: 0 no_index_used_pct: 100 rows_sent: 116 rows_examined: 116 rows_sent_avg: 116 rows_examined_avg: 116 first_seen: 2014-09-24 11:25:03 last_seen: 2014-09-24 11:25:03 digest: f81b5ce10baee9be754cf35fd245a516


• Better SHOW PROCESSLIST • No mutex contention • Live statistics for query

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Miscellaneous Views

processlist


processlist viewmysql> select * from processlist\G*************************** 1. row *************************** thd_id: 7890 conn_id: 7870 user: root@localhost db: mem command: Query state: update time: 0 current_statement: /* mem dbpool.default */ inser ...<truncated> lock_latency: 0 ps rows_examined: 0 rows_sent: 0 rows_affected: 0 tmp_tables: 0

tmp_disk_tables: 0 full_scan: NO last_statement: NULLlast_statement_latency: NULL last_wait: wait/io/table/sql/handler last_wait_latency: Still Waiting source: handler.cc:7274


Program Agenda



Installation

Summary Views

Procedures and Functions5

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• Make output human readable • Format time appropriately • Format bytes appropriately • Truncate output for large

width values for CLI • Extract object names • Dump a thread stack • Check instrumented actors

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Functions

format_time format_bytes format_path format_statement extract_table_from_file_name extract_schema_from_file_name ps_thread_stack ps_is_account_enabled


format_time() function

mysql> select format_time(23849723429) as time -> union select format_time(8327423749233) -> union select format_time(83274237492335);+-------------+| time |+-------------+| 23.85 ms || 8.33 s || 00:01:23.27 |+-------------+


format_bytes() function

mysql> select format_bytes(23423) as bytes -> union select format_bytes(23432423) -> union select format_bytes(42839479283) -> union select format_bytes(2293848203489);+-----------+| bytes |+-----------+| 22.87 KiB || 22.35 MiB || 39.90 GiB || 2.09 TiB |+-----------+


Performance Schema Config Helper Procedures

• ps_setup_show_disabled() / ps_setup_show_enabled() • ps_setup_disable_thread() / ps_setup_enable_thread() • ps_setup_disable_background_threads() /

ps_setup_enable_background_threads() • ps_setup_disable_instrument() / ps_setup_enable_instrument() • ps_setup_disable_consumer() / ps_setup_enable_consumer() • ps_setup_save() / ps_setup_reload_saved() • ps_setup_reset_to_default() / ps_truncate_all_tables()


• Dump all P_S data to a dot graph file to trace a thread • Look in the statement history

table to capture more info on a statement digest

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Statement Tracing Procedures

ps_trace_thread ps_trace_statement_digest ps_statement_avg_latency_histogram


ps_trace_statement_digest procedure

• ps_trace_statement_digest() analyses live traffic looking for certain statement digest for a period of time • Captures statistics on each matching statement it finds • Returns a report of the captured stats • An overall summary • A break down for the longest running example • An EXPLAIN (if the statement is not truncated)


ps_trace_statement_digest procedure

• ps_trace_statement_digest() parameters • in_digest The statement digest to analyse • in_runtime How long to run analysis for • in_interval How often to snapshot data • in_start_fresh Whether to truncate P_S tables first • in_auto_enable Whether to auto enable required config


ps_trace_statement_digest procedure examplemysql> call ps_trace_statement_digest(‘6134e9d6f25eb8e6cddf11f6938f202a’, 60, 1, true, true); +--------------------+ | SUMMARY STATISTICS | +--------------------+ | SUMMARY STATISTICS | +--------------------+ 1 row in set (59.93 sec)

+------------+-----------+-----------+-----------+---------------+------------+------------+ | executions | exec_time | lock_time | rows_sent | rows_examined | tmp_tables | full_scans | +------------+-----------+-----------+-----------+---------------+------------+------------+ | 360 | 1.41 s | 138.39 ms | 720 | 0 | 0 | 0 | +------------+-----------+-----------+-----------+---------------+------------+------------+ 1 row in set (59.93 sec)

+--------------------------------+-------+-----------+ | event_name | count | latency | +--------------------------------+-------+-----------+ | stage/sql/Sending data | 14 | 1.10 s | | stage/sql/update | 198 | 667.34 ms | | stage/sql/removing tmp table | 9 | 240.48 ms | ...


ps_trace_statement_digest procedure example+---------------------------+ | LONGEST RUNNING STATEMENT | +---------------------------+ | LONGEST RUNNING STATEMENT | +---------------------------+ 1 row in set (59.95 sec)

+-----------+-----------+-----------+-----------+---------------+------------+-----------+ | thread_id | exec_time | lock_time | rows_sent | rows_examined | tmp_tables | full_scan | +-----------+-----------+-----------+-----------+---------------+------------+-----------+ | 23277 | 77.64 ms | 97.00 us | 2 | 0 | 0 | 0 | +-----------+-----------+-----------+-----------+---------------+------------+-----------+ 1 row in set (59.95 sec)

+-------------------------------------------------------------------------------------------+ | sql_text | +-------------------------------------------------------------------------------------------+ | /* mem dbpool.default */ insert into `mem__quan`.`normalized_statements_by_server_by_schema` (firstSeen, lastSeen, normalized_statement_id, `schema`, server, id) values (1378983745000, 1378998600000, x'808ACEB88FC4B45BC47C4FE9D86C7F26', 'mem', '753c939e-1b99-11e3-b6d4-bc761a1f4f2f', x'7CFE81F98B1E3FE0895D1AA2C39B326D') ON DUPLICATE KEY UPDATE ... +-------------------------------------------------------------------------------------------+ ...


ps_trace_statement_digest procedure example+--------------------------------+----------+ | event_name | latency | +--------------------------------+----------+ | stage/sql/init | 10.41 ms | | stage/sql/checking permissions | 2.35 us | | stage/sql/Opening tables | 10.32 us | | stage/sql/init | 13.53 us | | stage/sql/System lock | 3.66 us | | stage/sql/update | 61.74 ms | | stage/sql/end | 1.11 us | | stage/sql/query end | 1.31 us | | stage/sql/closing tables | 5.44 ms | | stage/sql/freeing items | 23.31 us | +--------------------------------+----------+ 10 rows in set (59.99 sec)

+----+-------------+-------+------+---------------+------+---------+------+------+----------------+ | id | select_type | table | type | possible_keys | key | key_len | ref | rows | Extra | +----+-------------+-------+------+---------------+------+---------+------+------+----------------+ | 1 | SIMPLE | NULL | NULL | NULL | NULL | NULL | NULL | NULL | No tables used | +----+-------------+-------+------+---------------+------+---------+------+------+----------------+ ...


mysql sys schema oow 2014 - files.meetup.comfiles.meetup.com/107575/chicago_mysql_meetup_slides_20150422.… · MySQL sys views • Reference set of views solving various administrator

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