urs*_*ion 4 mysql statistics mysql-5.1
当我以 5 秒的间隔在 MySQL 中执行“显示状态”和“显示全局状态”时,我每次得到 291 个结果。但是,某些参数的值不同。下面是这些参数的列表:
状态变量名值全局状态变量名值 Aborted_clients 2350 Aborted_clients 2347 Binlog_cache_use 1494076 Binlog_cache_use 1493386 Bytes_received 180 Bytes_received 14514902897 发送字节数 8124 发送字节数 73596494244 Com_admin_commands 0 Com_admin_commands 847561 Com_alter_table 0 Com_alter_table 478 Com_begin 0 Com_begin 1009 Com_change_db 1 Com_change_db 8127737 Com_commit 0 Com_commit 1004 Com_create_table 0 Com_create_table 235 Com_create_trigger 0 Com_create_trigger 25 Com_create_view 0 Com_create_view 4 Com_delete 0 Com_delete 417012 Com_delete_multi 0 Com_delete_multi 218 Com_drop_table 0 Com_drop_table 239 Com_drop_view 0 Com_drop_view 8 Com_insert 0 Com_insert 109750 Com_insert_select 0 Com_insert_select 14 Com_kill 0 Com_kill 104 Com_lock_tables 0 Com_lock_tables 233 Com_optimize 0 Com_optimize 1 Com_rollback 0 Com_rollback 4 Com_select 0 Com_select 4955791 Com_set_option 1 Com_set_option 9473284 Com_show_collations 0 Com_show_collations 3109 Com_show_create_table 0 Com_show_create_table 1181 Com_show_create_trigger 0 Com_show_create_trigger 25 Com_show_databases 0 Com_show_databases 5 Com_show_engine_status 0 Com_show_engine_status 9538 Com_show_fields 0 Com_show_fields 516 Com_show_function_status 0 Com_show_function_status 4 Com_show_grants 0 Com_show_grants 4 Com_show_keys 0 Com_show_keys 60 Com_show_open_tables 1 Com_show_open_tables 26714 Com_show_plugins 0 Com_show_plugins 2 Com_show_procedure_status 0 Com_show_procedure_status 4 Com_show_processlist 0 Com_show_processlist 27338 Com_show_status 2 Com_show_status 16508 Com_show_table_status 0 Com_show_table_status 940 Com_show_tables 0 Com_show_tables 7 Com_show_triggers 0 Com_show_triggers 235 Com_show_variables 0 Com_show_variables 3135 Com_stmt_close 0 Com_stmt_close 279 Com_stmt_execute 0 Com_stmt_execute 284 Com_stmt_prepare 0 Com_stmt_prepare 284 Com_unlock_tables 0 Com_unlock_tables 233 Com_update 0 Com_update 967361 Com_update_multi 0 Com_update_multi 2272 连接 8132537 连接 8129927 Created_tmp_disk_tables 0 Created_tmp_disk_tables 349226 Created_tmp_files 63684 Created_tmp_files 63645 Created_tmp_tables 1 Created_tmp_tables 3893159 处理程序提交 0 处理程序提交 7480404 处理程序删除 0 处理程序删除 75596 Handler_prepare 0 Handler_prepare 2151290 Handler_read_first 0 Handler_read_first 29815473 Handler_read_key 0 Handler_read_key 1217425496 Handler_read_next 0 Handler_read_next 3826008161 Handler_read_prev 0 Handler_read_prev 2418519 Handler_read_rnd 0 Handler_read_rnd 9075133 Handler_read_rnd_next 81 Handler_read_rnd_next 3683107601 Handler_rollback 0 Handler_rollback 21610 处理程序更新 0 处理程序更新 17784530 Handler_write 80 Handler_write 591666282 Innodb_buffer_pool_pages_dirty 58 Innodb_buffer_pool_pages_dirty 67 Innodb_buffer_pool_pages_flushed 1161267 Innodb_buffer_pool_pages_flushed 1160463 Innodb_buffer_pool_read_requests 2863173268 Innodb_buffer_pool_read_requests 2855722562 Innodb_buffer_pool_write_requests 47910334 Innodb_buffer_pool_write_requests 47904489 Innodb_data_fsyncs 284362 Innodb_data_fsyncs 284205 Innodb_data_writes 3562289 Innodb_data_writes 3560356 Innodb_data_written 3802343424 Innodb_data_written 3774550528 Innodb_dblwr_pages_written 1161267 Innodb_dblwr_pages_written 1160463 Innodb_dblwr_writes 38015 Innodb_dblwr_writes 37994 Innodb_log_write_requests 7780429 Innodb_log_write_requests 7778131 Innodb_log_writes 2336822 Innodb_log_writes 2335731 Innodb_os_log_fsyncs 208319 Innodb_os_log_fsyncs 208204 Innodb_os_log_written 98765824 Innodb_os_log_written 97323008 Innodb_pages_written 1161267 Innodb_pages_written 1160463 Innodb_row_lock_time 137380 Innodb_row_lock_time 137349 Innodb_row_lock_waits 5392 Innodb_row_lock_waits 5386 Innodb_rows_deleted 75654 Innodb_rows_deleted 75596 Innodb_rows_inserted 7773757 Innodb_rows_inserted 7773709 Innodb_rows_read 3816403633 Innodb_rows_read 3808082321 Innodb_rows_updated 916125 Innodb_rows_updated 915711 Key_blocks_unused 422872 Key_blocks_unused 422915 Key_read_requests 320523319 Key_read_requests 320497057 密钥读取 6024194 密钥读取 6024151 Key_write_requests 7668445 Key_write_requests 7668386 Last_query_cost 10.499 Last_query_cost 0 第 194 章 Opened_files 1628563 Opened_files 1628148 Opened_table_definitions 0 Opened_table_definitions 5639 Opened_tables 0 Opened_tables 490561 Qcache_free_blocks 58892 Qcache_free_blocks 60662 Qcache_free_memory 240024696 Qcache_free_memory 245087632 Qcache_hits 30351231 Qcache_hits 30338589 Qcache_inserts 3605606 Qcache_inserts 3602774 Qcache_not_cached 1339432 Qcache_not_cached 1338776 Qcache_queries_in_cache 77058 Qcache_queries_in_cache 75273 Qcache_total_blocks 213544 Qcache_total_blocks 211643 查询 62827552 查询 62802229 问题 5 问题 62659646 Select_full_join 0 Select_full_join 63072 Select_full_range_join 0 Select_full_range_join 31 选择范围 0 选择范围 378850 选择_扫描 1 选择_扫描 2750215 慢查询 0 慢查询 26778 Sort_merge_passes 0 Sort_merge_passes 33570 排序范围 0 排序范围 366065 Sort_rows 0 Sort_rows 8796695 Sort_scan 0 Sort_scan 449489 Table_locks_immediate 19683336 Table_locks_immediate 19666285 线程缓存 196 线程缓存 193 Threads_connected 7 Threads_connected 10 正常运行时间 205696 正常运行时间 205606 Uptime_since_flush_status 205696 Uptime_since_flush_status 205606
既然两个查询都是一样的,那么为什么这么多参数有不同的值呢?请注意,我使用的是 MySQL 5.1 社区版。我在这个专用的 Windows 2008 数据库服务器中只有一个活动数据库。如果您需要任何其他信息,请告诉我。
Rol*_*DBA 12
和之间绝对有区别SHOW STATUS;SHOW GLOBAL STATUS;
SHOW GLOBAL STATUS; 将为您提供自 mysqld 启动以来为所有已连接或曾经连接的会话更新的状态变量。SHOW STATUS;将为您提供在会话中更新的状态变量。该命令也可以表示为SHOW SESSION STATUS;(正如 MySQL 文档所说,它显示当前连接的状态值)。为了在物理上显示差异,information_schema 数据库将它们分开为
INFORMATION_SCHEMA.GLOBAL_STATUSINFORMATION_SCHEMA.SESSION_STATUS这些 information_schema 表从 MySQL 5.1.12 开始就已经存在了。
为什么会有差异?
为了彻底展示差异,让我运行这些表的 INNER JOIN 以显示哪些值不同。这是查询:
SELECT a.variable_name,a.variable_value,b.variable_value
FROM information_schema.global_status A INNER join information_schema.session_status B
USING (variable_name) WHERE A.variable_value <> B.variable_value;
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请注意输出:
mysql> SELECT A.variable_name,A.variable_value,B.variable_value
-> FROM information_schema.global_status A INNER join information_schema.session_status B
-> USING (variable_name) WHERE A.variable_value <> B.variable_value;
+---------------------------+----------------+----------------+
| variable_name | variable_value | variable_value |
+---------------------------+----------------+----------------+
| BYTES_RECEIVED | 123641576598 | 7757 |
| BYTES_SENT | 149888451047 | 300001 |
| COM_ADMIN_COMMANDS | 121915 | 0 |
| COM_ALTER_TABLE | 111 | 0 |
| COM_BEGIN | 1 | 0 |
| COM_CALL_PROCEDURE | 530 | 0 |
| COM_CHANGE_DB | 1623 | 1 |
| COM_COMMIT | 19220 | 0 |
| COM_CREATE_FUNCTION | 4 | 0 |
| COM_CREATE_PROCEDURE | 126 | 0 |
| COM_CREATE_TABLE | 354 | 0 |
| COM_DEALLOC_SQL | 924 | 0 |
| COM_DELETE | 64668 | 0 |
| COM_DELETE_MULTI | 19 | 0 |
| COM_DROP_FUNCTION | 4 | 0 |
| COM_DROP_PROCEDURE | 148 | 0 |
| COM_DROP_TABLE | 238 | 0 |
| COM_EXECUTE_SQL | 945 | 0 |
| COM_INSERT | 1182379 | 0 |
| COM_INSERT_SELECT | 40673 | 0 |
| COM_KILL | 68 | 0 |
| COM_LOAD | 22386 | 0 |
| COM_LOCK_TABLES | 2 | 0 |
| COM_OPTIMIZE | 2 | 0 |
| COM_PREPARE_SQL | 948 | 0 |
| COM_REPAIR | 8 | 0 |
| COM_REPLACE | 34737 | 0 |
| COM_ROLLBACK | 13 | 0 |
| COM_SELECT | 1107225018 | 65 |
| COM_SET_OPTION | 602159 | 0 |
| COM_SHOW_BINLOGS | 8 | 0 |
| COM_SHOW_CHARSETS | 12 | 0 |
| COM_SHOW_COLLATIONS | 100 | 0 |
| COM_SHOW_CREATE_DB | 6 | 0 |
| COM_SHOW_CREATE_FUNC | 2453 | 0 |
| COM_SHOW_CREATE_PROC | 5684 | 0 |
| COM_SHOW_CREATE_TABLE | 1313 | 0 |
| COM_SHOW_DATABASES | 275 | 0 |
| COM_SHOW_EVENTS | 1 | 0 |
| COM_SHOW_FIELDS | 13666 | 1 |
| COM_SHOW_FUNCTION_STATUS | 362 | 0 |
| COM_SHOW_KEYS | 494 | 0 |
| COM_SHOW_PLUGINS | 2 | 0 |
| COM_SHOW_PROCEDURE_STATUS | 361 | 0 |
| COM_SHOW_PROCESSLIST | 488943 | 15 |
| COM_SHOW_SLAVE_STATUS | 4 | 0 |
| COM_SHOW_STATUS | 12315 | 10 |
| COM_SHOW_STORAGE_ENGINES | 30 | 0 |
| COM_SHOW_TABLE_STATUS | 320 | 0 |
| COM_SHOW_TABLES | 584 | 0 |
| COM_SHOW_TRIGGERS | 2 | 0 |
| COM_SHOW_VARIABLES | 190 | 1 |
| COM_STMT_CLOSE | 924 | 0 |
| COM_STMT_EXECUTE | 945 | 0 |
| COM_STMT_PREPARE | 948 | 0 |
| COM_TRUNCATE | 522 | 0 |
| COM_UNLOCK_TABLES | 2 | 0 |
| COM_UPDATE | 496041 | 0 |
| COM_UPDATE_MULTI | 625 | 0 |
| CREATED_TMP_DISK_TABLES | 16772 | 40 |
| CREATED_TMP_TABLES | 34336 | 63 |
| HANDLER_COMMIT | 1109540769 | 0 |
| HANDLER_DELETE | 12775993 | 0 |
| HANDLER_EXTERNAL_LOCK | 2228108102 | 24 |
| HANDLER_PREPARE | 2155764 | 0 |
| HANDLER_READ_FIRST | 23586 | 9 |
| HANDLER_READ_KEY | 18285349400 | 0 |
| HANDLER_READ_LAST | 13000 | 0 |
| HANDLER_READ_NEXT | 72142303428 | 0 |
| HANDLER_READ_PREV | 3000146 | 0 |
| HANDLER_READ_RND | 1261418742 | 156 |
| HANDLER_READ_RND_NEXT | 12320861765 | 7845 |
| HANDLER_ROLLBACK | 269376 | 0 |
| HANDLER_UPDATE | 2596924399 | 0 |
| HANDLER_WRITE | 8200421074 | 8241 |
| LAST_QUERY_COST | 0.000000 | 21.399123 |
| LAST_QUERY_PARTIAL_PLANS | 0 | 3 |
| OPENED_TABLE_DEFINITIONS | 2482 | 0 |
| OPENED_TABLES | 3619 | 0 |
| QUESTIONS | 1110214247 | 97 |
| SELECT_FULL_JOIN | 615 | 9 |
| SELECT_RANGE | 243635 | 0 |
| SELECT_SCAN | 47851 | 53 |
| SLOW_QUERIES | 29290 | 50 |
| SORT_MERGE_PASSES | 6 | 0 |
| SORT_RANGE | 179956 | 0 |
| SORT_ROWS | 321609927 | 156 |
| SORT_SCAN | 1829 | 39 |
| TABLE_OPEN_CACHE_HITS | 1109365721 | 13 |
| TABLE_OPEN_CACHE_MISSES | 1669 | 0 |
+---------------------------+----------------+----------------+
90 rows in set (0.03 sec)
mysql>
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看四个变量:
| BYTES_RECEIVED | 123641576598 | 7757 |
| BYTES_SENT | 149888451047 | 300001 |
| COM_ADMIN_COMMANDS | 121915 | 0 |
| COM_SHOW_PROCESSLIST | 488955 | 15 |
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这告诉你什么?
SHOW PROCESSLIST自mysqld启动以来,该命令已运行488,955次SHOW PROCESSLIST在我当前的会话中已运行 15 次您可以比较其他 86 个变量并以相同的方式解释它们。