an overview to mysql sys schema

An Overview to MySQL SYS Schema

By

MySQL Consulting Team

About MyDBOPS

•  MySQL Consulting •  MySQL Support •  Remote DBA support. •  Expert MySQL solutions •  MariaDB, Percona, Galera, TokuDB are supported too.

Agenda

•  Introduction •  Installation •  Summary Views

Introduction

Ø  Improvement over PS_helper Ø  MySQL 5.7.7 and higher includes the sys schema by default

Ø  Set of objects that helps DBAs and developers interpret data collected by the Performance Schema and other internals. Ø  sys schema objects can be used for typical tuning and diagnosis use cases.

Ø  Ease up the DBA’s task in understanding the internals. .

Introduction

Ø  Mark Leith is the Major Contributor.

Ø  Similar to Oracle V$ and X$ views that helps DBA’s.

§  Views that summarize Performance Schema data into more easily understandable

form.

§  Stored procedures that perform operaNons such as Performance Schema

configuraNon and generaNng diagnosNc reports.

§  Stored funcNons that query Performance Schema configuraNon and provide

formaQng services

§  FormaQng and helper funcNons.

Installation

Ø  The sys schema requires MySQL 5.5 or higher.

Ø  Can be installed through Workbench.

Ø  Else need to download sys_56.sql or sys_57.sql (depends if you use 5.6 or 5.7).just

import the sql file as usual

Install

$ git clone hXps://github.com/MarkLeith/mysql-‐sys.git /tmp/sys

cd /tmp/sys

Link to download: hXps://github.com/mysql/mysql-‐sys/archive/master.zip

Installation

To install :

mysql -‐u root -‐p < sys_56.sql Ø  ValidaNng sys schema a]er loading

mysql> select * from sys.version; +-‐-‐-‐-‐-‐-‐-‐-‐-‐-‐-‐-‐-‐+-‐-‐-‐-‐-‐-‐-‐-‐-‐-‐-‐-‐-‐-‐-‐-‐-‐+ | sys_version | mysql_version | +-‐-‐-‐-‐-‐-‐-‐-‐-‐-‐-‐-‐-‐+-‐-‐-‐-‐-‐-‐-‐-‐-‐-‐-‐-‐-‐-‐-‐-‐-‐+ | 1.5.0 | 5.6.27-‐76.0-‐log | +-‐-‐-‐-‐-‐-‐-‐-‐-‐-‐-‐-‐-‐+-‐-‐-‐-‐-‐-‐-‐-‐-‐-‐-‐-‐-‐-‐-‐-‐-‐+

mysql> select * from sys.schema_object_overview where db='sys'; +-‐-‐-‐-‐-‐+-‐-‐-‐-‐-‐-‐-‐-‐-‐-‐-‐-‐-‐-‐-‐+-‐-‐-‐-‐-‐-‐-‐+ | db | object_type | count | +-‐-‐-‐-‐-‐+-‐-‐-‐-‐-‐-‐-‐-‐-‐-‐-‐-‐-‐-‐-‐+-‐-‐-‐-‐-‐-‐-‐+ | sys | VIEW | 87 | | sys | BASE TABLE | 1 | | sys | INDEX (BTREE) | 1 | | sys | TRIGGER | 2 | | sys | FUNCTION | 20 | | sys | PROCEDURE | 26 | +-‐-‐-‐-‐-‐+-‐-‐-‐-‐-‐-‐-‐-‐-‐-‐-‐-‐-‐-‐-‐+-‐-‐-‐-‐-‐-‐-‐+

Installation

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 innodb_buffer_stats_by_schema innodb_buffer_stats_by_table innodb_lock_waits 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 latest_file_io metrics processlist ps_check_lost_instrumentation schema_auto_increment_columns schema_index_statistics schema_object_overview schema_redundant_indexes

schema_table_statistics schema_table_statistics_with_buffer schema_tables_with_full_table_scans schema_unused_indexes session 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 sys_config 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 version wait_classes_global_by_avg_latency wait_classes_global_by_latency waits_by_host_by_latency

Installation

waits_by_user_by_latency waits_global_by_latency x$host_summary x$host_summary_by_file_io x$host_summary_by_file_io_type x$host_summary_by_stages x$host_summary_by_statement_latency x$host_summary_by_statement_type x$innodb_buffer_stats_by_schema x$innodb_buffer_stats_by_table x$innodb_lock_waits x$io_by_thread_by_latency x$io_global_by_file_by_bytes x$io_global_by_file_by_latency x$io_global_by_wait_by_bytes x$io_global_by_wait_by_latency x$latest_file_io x$processlist x$ps_digest_95th_percentile_by_avg_us x$ps_digest_avg_latency_distribution x$ps_schema_table_statistics_io x$schema_flattened_keys

x$schema_index_statistics x$schema_table_statistics x$schema_table_statistics_with_buffer x$schema_tables_with_full_table_scans x$session x$statement_analysis x$statements_with_errors_or_warnings x$statements_with_full_table_scans x$statements_with_runtimes_in_95th_percentile x$statements_with_sorting x$statements_with_temp_tables x$user_summary x$user_summary_by_file_io x$user_summary_by_file_io_type x$user_summary_by_stages x$user_summary_by_statement_latency x$user_summary_by_statement_type x$wait_classes_global_by_avg_latency x$wait_classes_global_by_latency x$waits_by_host_by_latency x$waits_by_user_by_latency x$waits_global_by_latency

Summary Views

Ø  Contains many views that summarize Performance Schema tables in various ways. Display all running and acNve real Nme process. Ø  Most of these views come in pairs, such that one member of the pair has the same name as the other member, plus a x$ prefix. For Ex: mysql> SELECT * FROM host_summary_by_file_io; +-‐-‐-‐-‐-‐-‐-‐-‐-‐-‐-‐-‐+-‐-‐-‐-‐-‐-‐-‐+-‐-‐-‐-‐-‐-‐-‐-‐-‐-‐-‐-‐+ | host | ios | io_latency | +-‐-‐-‐-‐-‐-‐-‐-‐-‐-‐-‐-‐+-‐-‐-‐-‐-‐-‐-‐+-‐-‐-‐-‐-‐-‐-‐-‐-‐-‐-‐-‐+ | localhost | 67570 | 5.38 s | | background | 3468 | 4.18 s | +-‐-‐-‐-‐-‐-‐-‐-‐-‐-‐-‐-‐+-‐-‐-‐-‐-‐-‐-‐+-‐-‐-‐-‐-‐-‐-‐-‐-‐-‐-‐-‐+

mysql> SELECT * FROM x$host_summary_by_file_io; +-‐-‐-‐-‐-‐-‐-‐-‐-‐-‐-‐-‐+-‐-‐-‐-‐-‐-‐-‐+-‐-‐-‐-‐-‐-‐-‐-‐-‐-‐-‐-‐-‐-‐-‐+ | host | ios | io_latency | +-‐-‐-‐-‐-‐-‐-‐-‐-‐-‐-‐-‐+-‐-‐-‐-‐-‐-‐-‐+-‐-‐-‐-‐-‐-‐-‐-‐-‐-‐-‐-‐-‐-‐-‐+ | localhost | 67574 | 5380678125144 | | background | 3474 | 4758696829416 | +-‐-‐-‐-‐-‐-‐-‐-‐-‐-‐-‐-‐+-‐-‐-‐-‐-‐-‐-‐+-‐-‐-‐-‐-‐-‐-‐-‐-‐-‐-‐-‐-‐-‐-‐+

Summary Views

Resource Consuming user

mysql> select * from user_summary\G *************************** 1. row *************************** user: root statements: 3185 statement_latency: 2.67 h statement_avg_latency: 3.02 s table_scans: 190 file_ios: 548019 file_io_latency: 15.58 m current_connections: 3 total_connections: 6 unique_hosts: 1 current_memory: 0 bytes total_memory_allocated: 0 bytes *************************** 2. row ***************************

Summary Views

Internal File IO ConsumpNon mysql> select * from user_summary_by_file_io_type where user = 'root'; +-‐-‐-‐-‐-‐-‐+-‐-‐-‐-‐-‐-‐-‐-‐-‐-‐-‐-‐-‐-‐-‐-‐-‐-‐-‐-‐-‐-‐-‐-‐-‐-‐-‐-‐-‐-‐-‐-‐-‐-‐-‐-‐-‐-‐+-‐-‐-‐-‐-‐-‐-‐-‐+-‐-‐-‐-‐-‐-‐-‐-‐-‐-‐-‐+-‐-‐-‐-‐-‐-‐-‐-‐-‐-‐-‐-‐-‐+ | user | event_name | total | latency | max_latency | +-‐-‐-‐-‐-‐-‐+-‐-‐-‐-‐-‐-‐-‐-‐-‐-‐-‐-‐-‐-‐-‐-‐-‐-‐-‐-‐-‐-‐-‐-‐-‐-‐-‐-‐-‐-‐-‐-‐-‐-‐-‐-‐-‐-‐+-‐-‐-‐-‐-‐-‐-‐-‐+-‐-‐-‐-‐-‐-‐-‐-‐-‐-‐-‐+-‐-‐-‐-‐-‐-‐-‐-‐-‐-‐-‐-‐-‐+ | root | wait/io/file/innodb/innodb_data_file | 538430 | 13.57 m | 1.11 s | | root | wait/io/file/innodb/innodb_log_file | 3608 | 2.05 m | 512.93 ms | | root | wait/io/file/sql/FRM | 10579 | 7.95 s | 315.66 ms | | root | wait/io/file/myisam/dfile | 69 | 361.88 ms | 287.33 ms | | root | wait/io/file/sql/io_cache | 487 | 67.34 ms | 39.98 ms | | root | wait/io/file/sql/file_parser | 204 | 16.90 ms | 14.78 ms | | root | wait/io/file/archive/data | 256 | 853.56 us | 13.89 us | | root | wait/io/file/sql/dbopt | 33 | 564.94 us | 67.70 us | | root | wait/io/file/myisam/kfile | 85 | 304.53 us | 74.57 us | | root | wait/io/file/sql/misc | 7 | 145.62 us | 33.73 us | +-‐-‐-‐-‐-‐-‐+-‐-‐-‐-‐-‐-‐-‐-‐-‐-‐-‐-‐-‐-‐-‐-‐-‐-‐-‐-‐-‐-‐-‐-‐-‐-‐-‐-‐-‐-‐-‐-‐-‐-‐-‐-‐-‐-‐+-‐-‐-‐-‐-‐-‐-‐-‐+-‐-‐-‐-‐-‐-‐-‐-‐-‐-‐-‐+-‐-‐-‐-‐-‐-‐-‐-‐-‐-‐-‐-‐-‐+

Summary Views

Resource ConsumpNon based on Statements mysql> select * from user_summary_by_statement_type where user = 'root'; +-‐-‐-‐-‐-‐-‐+-‐-‐-‐-‐-‐-‐-‐-‐-‐-‐-‐-‐-‐-‐-‐-‐-‐-‐-‐+-‐-‐-‐-‐-‐-‐-‐+-‐-‐-‐-‐-‐-‐-‐-‐-‐-‐-‐-‐-‐-‐-‐+-‐-‐-‐-‐-‐-‐-‐-‐-‐-‐-‐-‐-‐+-‐-‐-‐-‐-‐-‐-‐-‐-‐-‐-‐-‐-‐-‐+-‐-‐-‐-‐-‐-‐-‐-‐-‐-‐-‐+-‐-‐-‐-‐-‐-‐-‐-‐-‐-‐-‐-‐-‐-‐-‐+-‐-‐-‐-‐-‐-‐-‐-‐-‐-‐-‐-‐-‐-‐-‐+-‐-‐-‐-‐-‐-‐-‐-‐-‐-‐-‐-‐+ | user | statement | total | total_latency | max_latency | lock_latency | rows_sent | rows_examined | rows_affected | full_scans | +-‐-‐-‐-‐-‐-‐+-‐-‐-‐-‐-‐-‐-‐-‐-‐-‐-‐-‐-‐-‐-‐-‐-‐-‐-‐+-‐-‐-‐-‐-‐-‐-‐+-‐-‐-‐-‐-‐-‐-‐-‐-‐-‐-‐-‐-‐-‐-‐+-‐-‐-‐-‐-‐-‐-‐-‐-‐-‐-‐-‐-‐+-‐-‐-‐-‐-‐-‐-‐-‐-‐-‐-‐-‐-‐-‐+-‐-‐-‐-‐-‐-‐-‐-‐-‐-‐-‐+-‐-‐-‐-‐-‐-‐-‐-‐-‐-‐-‐-‐-‐-‐-‐+-‐-‐-‐-‐-‐-‐-‐-‐-‐-‐-‐-‐-‐-‐-‐+-‐-‐-‐-‐-‐-‐-‐-‐-‐-‐-‐-‐+ | root | insert | 1232 | 2.69 h | 19.52 s | 0 ps | 0 | 0 | 10367218 | 0 | | root | create_table | 128 | 1.04 m | 4.41 s | 0 ps | 0 | 0 | 0 | 0 | | root | drop_table | 150 | 31.18 s | 2.74 s | 0 ps | 0 | 0 | 0 | 0 | | root | select | 101 | 9.38 s | 889.77 ms | 1.14 s | 44807 | 65631 | 0 | 45 | | root | Field List | 134 | 6.21 s | 1.15 s | 1.49 s | 0 | 0 | 0 | 0 | | root | unlock_tables | 128 | 1.85 s | 149.67 ms | 0 ps | 0 | 0 | 0 | 0 | | root | show_tables | 7 | 779.85 ms | 414.56 ms | 701.33 ms | 345 | 345 | 0 | 7 | | root | error | 1 | 748.68 ms | 748.68 ms | 0 ps | 0 | 0 | 0 | 0 | | root | show_databases | 8 | 703.16 ms | 644.97 ms | 585.93 ms | 75 | 75 | 0 | 8 | | root | show_variables | 2 | 389.08 ms | 388.09 ms | 45.45 ms | 1 | 1008 | 0 | 2 | | root | show_processlist | 80 | 334.39 ms | 236.12 ms | 0 ps | 0 | 0 | 0 | 0 | | root | set_option | 586 | 224.78 ms | 190.99 ms | 205.00 us | 0 | 0 | 0 | 0 | | root | show_create_table | 34 | 116.54 ms | 108.95 ms | 0 ps | 0 | 0 | 0 | 0 | | root | lock_tables | 129 | 73.91 ms | 10.81 ms | 70.90 ms | 0 | 0 | 0 | 0 | | root | alter_table | 255 | 36.52 ms | 6.93 ms | 0 ps | 0 | 0 | 0 | 0 | | root | change_db | 33 | 25.66 ms | 24.29 ms | 0 ps | 0 | 0 | 0 | 0 | | root | show_fields | 66 | 22.35 ms | 2.10 ms | 0 ps | 276 | 276 | 0 | 66 | | root | show_triggers | 33 | 17.33 ms | 1.59 ms | 0 ps | 0 | 0 | 0 | 33 | | root | show_table_status | 33 | 8.69 ms | 384.26 us | 0 ps | 33 | 33 | 0 | 33 | | root | create_db | 7 | 1.47 ms | 332.44 us | 0 ps | 0 | 0 | 7 | 0 | | root | flush | 1 | 902.74 us | 902.74 us | 822.00 us | 0 | 0 | 0 | 0 | | root | jump_if_not | 295 | 833.81 us | 20.04 us | 0 ps | 0 | 0 | 0 | 0 | | root | create_procedure | 2 | 393.48 us | 226.63 us | 220.00 us | 0 | 0 | 0 | 0 | | root | drop_procedure | 2 | 392.08 us | 301.71 us | 289.00 us | 0 | 0 | 0 | 0 | | root | Init DB | 10 | 338.30 us | 73.47 us | 0 ps | 0 | 0 | 0 | 0 | | root | freturn | 46 | 281.04 us | 39.39 us | 0 ps | 0 | 0 | 0 | 0 | | root | Statistics | 3 | 67.26 us | 31.78 us | 0 ps | 0 | 0 | 0 | 0 | | root | Quit | 3 | 54.40 us | 19.70 us | 0 ps | 0 | 0 | 0 | 0 | +-‐-‐-‐-‐-‐-‐+-‐-‐-‐-‐-‐-‐-‐-‐-‐-‐-‐-‐-‐-‐-‐-‐-‐-‐-‐+-‐-‐-‐-‐-‐-‐-‐+-‐-‐-‐-‐-‐-‐-‐-‐-‐-‐-‐-‐-‐-‐-‐+-‐-‐-‐-‐-‐-‐-‐-‐-‐-‐-‐-‐-‐+-‐-‐-‐-‐-‐-‐-‐-‐-‐-‐-‐-‐-‐-‐+-‐-‐-‐-‐-‐-‐-‐-‐-‐-‐-‐+-‐-‐-‐-‐-‐-‐-‐-‐-‐-‐-‐-‐-‐-‐-‐+-‐-‐-‐-‐-‐-‐-‐-‐-‐-‐-‐-‐-‐-‐-‐+-‐-‐-‐-‐-‐-‐-‐-‐-‐-‐-‐-‐+

Summary Views

Resource ConsumpNon based on host connecNvity

mysql> select * from sys.host_summary\G *************************** 1. row *************************** host: localhost statements: 15588 statement_latency: 2.76 h statement_avg_latency: 637.81 ms table_scans: 198 file_ios: 566859 file_io_latency: 16.10 m current_connections: 3 total_connections: 6 unique_users: 1 current_memory: 0 bytes total_memory_allocated: 0 bytes 1 row in set (0.15 sec)

Summary Views

InnoDB Buffer Pool Stats based on Table.

mysql> select * from sys.innodb_buffer_stats_by_table; +-‐-‐-‐-‐-‐-‐-‐-‐-‐-‐-‐-‐-‐-‐-‐-‐-‐+-‐-‐-‐-‐-‐-‐-‐-‐-‐-‐-‐-‐-‐-‐-‐-‐-‐-‐-‐-‐-‐-‐-‐-‐-‐-‐-‐-‐+-‐-‐-‐-‐-‐-‐-‐-‐-‐-‐-‐-‐+-‐-‐-‐-‐-‐-‐-‐-‐-‐-‐-‐-‐+-‐-‐-‐-‐-‐-‐-‐-‐-‐+-‐-‐-‐-‐-‐-‐-‐-‐-‐-‐-‐-‐-‐-‐+-‐-‐-‐-‐-‐-‐-‐-‐-‐-‐-‐+-‐-‐-‐-‐-‐-‐-‐-‐-‐-‐-‐-‐-‐+ | object_schema | object_name | allocated | data | pages | pages_hashed | pages_old | rows_cached | +-‐-‐-‐-‐-‐-‐-‐-‐-‐-‐-‐-‐-‐-‐-‐-‐-‐+-‐-‐-‐-‐-‐-‐-‐-‐-‐-‐-‐-‐-‐-‐-‐-‐-‐-‐-‐-‐-‐-‐-‐-‐-‐-‐-‐-‐+-‐-‐-‐-‐-‐-‐-‐-‐-‐-‐-‐-‐+-‐-‐-‐-‐-‐-‐-‐-‐-‐-‐-‐-‐+-‐-‐-‐-‐-‐-‐-‐-‐-‐+-‐-‐-‐-‐-‐-‐-‐-‐-‐-‐-‐-‐-‐-‐+-‐-‐-‐-‐-‐-‐-‐-‐-‐-‐-‐+-‐-‐-‐-‐-‐-‐-‐-‐-‐-‐-‐-‐-‐+ | testsoffice_sql | TEST_TABLE_0 | 22.20 GiB | 19.42 GiB | 1455134 | 1455134 | 1455134 | 16828504 | | testsoffice_sql | TEST_TABLE_l | 947.80 MiB | 887.60 MiB | 60659 | 60659 | 60659 | 4393691 | | testsoffice_sql | TEST_TABLE_2 | 120.70 MiB | 74.42 MiB | 7725 | 7725 | 7725 | 1482091 | | testsoffice_sql | TEST_TABLE_3 | 60.55 MiB | 44.19 MiB | 3875 | 3875 | 3875 | 545475 | | testsoffice_sql | TEST_TABLE_4 | 55.58 MiB | 49.66 MiB | 3557 | 3557 | 3557 | 671925 | | testrsync | TEST_TABLE_5 | 53.50 MiB | 37.03 MiB | 3424 | 3424 | 3424 | 205086 | | testsoffice_sql | TEST_TABLE_6 | 29.23 MiB | 18.43 MiB | 1871 | 1871 | 1871 | 43250 | | testsoffice_sql | TEST_TABLE_7 | 21.31 MiB | 19.37 MiB | 1364 | 1364 | 1364 | 42888 | | testrsync | TEST_TABLE_8 | 18.80 MiB | 13.79 MiB | 1203 | 1203 | 1203 | 63859 | | testsoffice_sql | TEST_TABLE_9 | 14.95 MiB | 9.87 MiB | 957 | 957 | 957 | 49498 | +-‐-‐-‐-‐-‐-‐-‐-‐-‐-‐-‐-‐-‐-‐-‐-‐-‐+-‐-‐-‐-‐-‐-‐-‐-‐-‐-‐-‐-‐-‐-‐-‐-‐-‐-‐-‐-‐-‐-‐-‐-‐-‐-‐-‐-‐+-‐-‐-‐-‐-‐-‐-‐-‐-‐-‐-‐-‐+-‐-‐-‐-‐-‐-‐-‐-‐-‐-‐-‐-‐+-‐-‐-‐-‐-‐-‐-‐-‐-‐+-‐-‐-‐-‐-‐-‐-‐-‐-‐-‐-‐-‐-‐-‐+-‐-‐-‐-‐-‐-‐-‐-‐-‐-‐-‐+-‐-‐-‐-‐-‐-‐-‐-‐-‐-‐-‐-‐-‐+

Summary Views

Finding the Hot tables mysql> select * from sys.schema_table_statistics limit 2\G *************************** 1. row *************************** table_schema: test_database table_name: test_table1 total_latency: 2.68 h rows_fetched: 0 fetch_latency: 0 ps rows_inserted: 10426278 insert_latency: 2.68 h rows_updated: 0 update_latency: 0 ps rows_deleted: 0 delete_latency: 0 ps io_read_requests: 19 io_read: 5.31 KiB io_read_latency: 43.69 us io_write_requests: 37 io_write: 6.10 KiB io_write_latency: 54.50 us io_misc_requests: 24 io_misc_latency: 40.31 ms

*************************** 2. row *************** table_schema: db2 table_name: table_2 total_latency: 3.76 s rows_fetched: 0 fetch_latency: 0 ps rows_inserted: 7488 insert_latency: 3.76 s rows_updated: 0 update_latency: 0 ps rows_deleted: 0 delete_latency: 0 ps io_read_requests: 19 io_read: 1.80 KiB io_read_latency: 39.66 us io_write_requests: 101 io_write: 1.25 MiB io_write_latency: 1.72 ms io_misc_requests: 64 io_misc_latency: 3.45 s

Summary Views

Memory DistribuNon inside MySQL select * from memory_global_by_current_bytes limit 10;

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

| event_name | current_count | current_alloc | current_avg_alloc | high_count | high_alloc | high_avg_alloc |

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

| memory/performance_schema/events_statements_history_long | 1 | 13.66 MiB | 13.66 MiB | 1 | 13.66 MiB | 13.66 MiB |

| memory/performance_schema/events_statements_history_long.tokens | 1 | 9.77 MiB | 9.77 MiB | 1 | 9.77 MiB | 9.77 MiB |

| memory/performance_schema/events_statements_history_long.sqltext | 1 | 9.77 MiB | 9.77 MiB | 1 | 9.77 MiB | 9.77 MiB |

| memory/performance_schema/events_statements_summary_by_digest.tokens | 1 | 9.77 MiB | 9.77 MiB | 1 | 9.77 MiB | 9.77 MiB |

| memory/performance_schema/table_handles | 1 | 9.00 MiB | 9.00 MiB | 1 | 9.00 MiB | 9.00 MiB |

| memory/performance_schema/events_statements_summary_by_thread_by_event_name | 1 | 8.67 MiB | 8.67 MiB | 1 | 8.67 MiB | 8.67 MiB |

| memory/performance_schema/memory_summary_by_thread_by_event_name | 1 | 5.62 MiB | 5.62 MiB | 1 | 5.62 MiB | 5.62 MiB |

| memory/performance_schema/events_statements_summary_by_digest | 1 | 4.88 MiB | 4.88 MiB | 1 | 4.88 MiB | 4.88 MiB |

| memory/performance_schema/events_statements_summary_by_account_by_event_name | 1 | 4.33 MiB | 4.33 MiB | 1 | 4.33 MiB | 4.33 MiB |

| memory/performance_schema/events_statements_summary_by_host_by_event_name | 1 | 4.33 MiB | 4.33 MiB | 1 | 4.33 MiB | 4.33 MiB |

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

Summary Views

Finding the Global Wait Latency mysql> select * from waits_global_by_latency limit 10;

+-‐-‐-‐-‐-‐-‐-‐-‐-‐-‐-‐-‐-‐-‐-‐-‐-‐-‐-‐-‐-‐-‐-‐-‐-‐-‐-‐-‐-‐-‐-‐-‐-‐-‐-‐-‐-‐-‐-‐-‐-‐-‐-‐-‐-‐-‐-‐-‐-‐-‐-‐-‐+-‐-‐-‐-‐-‐-‐-‐-‐-‐-‐+-‐-‐-‐-‐-‐-‐-‐-‐-‐-‐-‐-‐-‐-‐-‐+-‐-‐-‐-‐-‐-‐-‐-‐-‐-‐-‐-‐-‐+-‐-‐-‐-‐-‐-‐-‐-‐-‐-‐-‐-‐-‐+ | events | total | total_latency | avg_latency | max_latency | +-‐-‐-‐-‐-‐-‐-‐-‐-‐-‐-‐-‐-‐-‐-‐-‐-‐-‐-‐-‐-‐-‐-‐-‐-‐-‐-‐-‐-‐-‐-‐-‐-‐-‐-‐-‐-‐-‐-‐-‐-‐-‐-‐-‐-‐-‐-‐-‐-‐-‐-‐-‐+-‐-‐-‐-‐-‐-‐-‐-‐-‐-‐+-‐-‐-‐-‐-‐-‐-‐-‐-‐-‐-‐-‐-‐-‐-‐+-‐-‐-‐-‐-‐-‐-‐-‐-‐-‐-‐-‐-‐+-‐-‐-‐-‐-‐-‐-‐-‐-‐-‐-‐-‐-‐+ | wait/io/file/innodb/innodb_data_file | 3025950 | 2.84 h | 3.38 ms | 1.11 s | | wait/io/table/sql/handler | 11025308 | 2.83 h | 923.86 us | 1.56 s | | wait/io/file/innodb/innodb_log_file | 56941 | 32.53 m | 34.28 ms | 565.85 ms | | wait/io/file/sql/FRM | 12044 | 7.96 s | 660.69 us | 315.66 ms | | wait/io/file/myisam/dfile | 93 | 361.95 ms | 3.89 ms | 287.33 ms | | wait/io/file/sql/io_cache | 487 | 67.34 ms | 138.28 us | 39.98 ms | | wait/io/file/sql/file_parser | 104 | 15.29 ms | 147.05 us | 14.78 ms | | wait/io/file/archive/data | 256 | 853.56 us | 3.33 us | 13.89 us | | wait/io/file/sql/dbopt | 33 | 564.94 us | 17.12 us | 67.70 us | | wait/io/file/sql/ERRMSG | 5 | 518.37 us | 103.67 us | 468.87 us | | wait/io/file/myisam/kfile | 118 | 403.17 us | 3.42 us | 74.57 us | | wait/lock/table/sql/handler | 127 | 301.39 us | 2.37 us | 5.13 us | | wait/io/file/sql/misc | 7 | 145.62 us | 20.80 us | 33.73 us | | wait/io/file/sql/casetest | 10 | 142.10 us | 14.21 us | 80.76 us | | wait/io/file/sql/pid | 3 | 136.44 us | 45.48 us | 108.86 us | | wait/io/file/mysys/cnf | 5 | 51.82 us | 10.36 us | 20.47 us | | wait/io/file/mysys/charset | 3 | 25.89 us | 8.63 us | 13.81 us | | wait/io/file/keyring_file/keyring_file_data | 4 | 18.76 us | 4.69 us | 13.98 us | | wait/io/file/sql/global_ddl_log | 2 | 6.06 us | 3.03 us | 3.49 us | | wait/io/file/keyring_file/keyring_backup_file_data | 1 | 4.35 us | 4.35 us | 4.35 us | +-‐-‐-‐-‐-‐-‐-‐-‐-‐-‐-‐-‐-‐-‐-‐-‐-‐-‐-‐-‐-‐-‐-‐-‐-‐-‐-‐-‐-‐-‐-‐-‐-‐-‐-‐-‐-‐-‐-‐-‐-‐-‐-‐-‐-‐-‐-‐-‐-‐-‐-‐-‐+-‐-‐-‐-‐-‐-‐-‐-‐-‐-‐+-‐-‐-‐-‐-‐-‐-‐-‐-‐-‐-‐-‐-‐-‐-‐+-‐-‐-‐-‐-‐-‐-‐-‐-‐-‐-‐-‐-‐+-‐-‐-‐-‐-‐-‐-‐-‐-‐-‐-‐-‐-‐+

Summary Views

Tables with FTS ( Full Table Scan) queries

mysql> select * from schema_tables_with_full_table_scans; +-‐-‐-‐-‐-‐-‐-‐-‐-‐-‐-‐-‐-‐-‐-‐-‐-‐+-‐-‐-‐-‐-‐-‐-‐-‐-‐-‐-‐-‐-‐-‐-‐-‐-‐-‐-‐+-‐-‐-‐-‐-‐-‐-‐-‐-‐-‐-‐-‐-‐-‐-‐-‐-‐-‐-‐+-‐-‐-‐-‐-‐-‐-‐-‐-‐-‐-‐+ | object_schema | object_name | rows_full_scanned | latency | +-‐-‐-‐-‐-‐-‐-‐-‐-‐-‐-‐-‐-‐-‐-‐-‐-‐+-‐-‐-‐-‐-‐-‐-‐-‐-‐-‐-‐-‐-‐-‐-‐-‐-‐-‐-‐+-‐-‐-‐-‐-‐-‐-‐-‐-‐-‐-‐-‐-‐-‐-‐-‐-‐-‐-‐+-‐-‐-‐-‐-‐-‐-‐-‐-‐-‐-‐+ | dbbase_sample_2 | TESTSTATS | 1639668 | 20.16 m | | dbbase_sample_2 | TABLEP_TESTS | 174365 | 814.35 ms | | dbbase_sample_2 | TESTTB | 83577 | 195.37 ms | | dbbase_sample_2 | TABLE_STATS | 14124 | 31.96 s | | dbbase_sample_2 | TABLE_FILE1 | 3215 | 31.18 ms | | dbbase_sample_2 | TABLE_FILE2 | 2552 | 27.44 ms | | dbbase_sample_2 | TABLE_FILE4 | 2306 | 368.97 ms | | database_sample | TABLE_FILE6 | 1602 | 151.13 ms | | dbbase_sample_2 | TABLE_FILE8 | 16 | 16.13 ms | | sys | TABLE_FILE9 | 6 | 137.39 us | +-‐-‐-‐-‐-‐-‐-‐-‐-‐-‐-‐-‐-‐-‐-‐-‐-‐+-‐-‐-‐-‐-‐-‐-‐-‐-‐-‐-‐-‐-‐-‐-‐-‐-‐-‐-‐+-‐-‐-‐-‐-‐-‐-‐-‐-‐-‐-‐-‐-‐-‐-‐-‐-‐-‐-‐+-‐-‐-‐-‐-‐-‐-‐-‐-‐-‐-‐+

Summary Views

Find queries creaNng temp tables.

mysql> select * from statements_with_temp_tables limit 2\G *************************** 1. row *************************** query: SELECT DISTINCT ROW `COLUMN3` FRO ... NOT IN (...) ORDER BY `COLUMN4` db: TEST_DB exec_count: 321 total_latency: 1.59 s memory_tmp_tables: 321 disk_tmp_tables: 0 avg_tmp_tables_per_query: 1 tmp_tables_to_disk_pct: 0 first_seen: 2016-‐04-‐03 11:00:02 last_seen: 2016-‐04-‐05 16:20:01 digest: ad3f312c08d1e324cde5ff9e7f5b7513 *************************** 2. row *************************** query: SELECT DISTINCTROW ( `COLUMN1` ) FROM `TABLE` db: TEST_DB exec_count: 176 total_latency: 50.65 ms memory_tmp_tables: 176 disk_tmp_tables: 0 avg_tmp_tables_per_query: 1 tmp_tables_to_disk_pct: 0 first_seen: 2016-‐04-‐03 11:52:04 last_seen: 2016-‐04-‐05 13:52:04 digest: d0a288bf2140849667259fcfbf2b9619

Summary Views

•  Sys schema can help a lot in monitoring and Fine Tuning.

•  Monitoring and alert systems can benefitted a lot by it.

•  Seems like MEM 3.2 has implemented most of sys schema tables.

•  Large scale MySQL Farms can poll the sys schema views to

centralized servers for historical data analysis.

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an overview to mysql sys schema

Engineering