Invalidating query cache mysql

Standard Query Cache Standard Query Cache - Checking query spaces are up-to-date: [Post] Ehcache General Data Region - key: Post Update Timestamps Cache - [Post] last update timestamp: 5872026465406976, result set timestamp: 5872026465492992 Standard Query Cache - Returning cached query results Jdbc Transaction - committed JDBC Connection If you enjoy reading this article, you might want to subscribe to my newsletter and get a discount for my book as well.

去slave从库上查看运行状态,果然Seconds_Behind_Master: 28810,而且提示Slave_SQL_Running_State: System lock而且这个是变化的,有的时候提示Slave_SQL_Running_State: invalidating query cache entries (table),而且Seconds_Behind_Master: 29086 不停的增长着: show slave status\G *************************** 1.

invalidating query cache mysql-63

In theory, the cache exists to speed up your application by responding to the same query with results directly from memory instead of parsing, optimizing, and re-executing the query against the database.

Assuming that scalability could be improved, the limiting factor of the query cache is that since only queries that hit the cache will see improvement; it is unlikely to improve We concur with the research performed by Jiamin Huang, Barzan Mozafari, Grant Schoenebeck, Thomas F. We considered what improvements we could make to query cache versus optimizations that we could make which provide improvements to .

While these choices themselves are orthogonal, engineering resources are finite.

row *************************** Slave_IO_State: Waiting for master to send event Master_Host: 10.249.3.11 Master_User: repl Master_Port: 3317 Connect_Retry: 60 Master_Log_File: mysql-bin.000027 Read_Master_Log_Pos: 909456416 Relay_Log_File: mysql-relay-bin.000020 Relay_Log_Pos: 19878093 Relay_Master_Log_File: mysql-bin.000014 Slave_IO_Running: Yes Slave_SQL_Running: Yes Replicate_Do_DB: Replicate_Ignore_DB: Replicate_Do_Table: Replicate_Ignore_Table: Replicate_Wild_Do_Table: Replicate_Wild_Ignore_Table: Last_Errno: 0 Last_Error: Skip_Counter: 0 Exec_Master_Log_Pos: 19877880 Relay_Log_Space: 14868115381 Until_Condition: None Until_Log_File: Until_Log_Pos: 0 Master_SSL_Allowed: No Master_SSL_CA_File: Master_SSL_CA_Path: Master_SSL_Cert: Master_SSL_Cipher: Master_SSL_Key: Master_SSL_Verify_Server_Cert: No Last_IO_Errno: 0 Last_IO_Error: Last_SQL_Errno: 0 Last_SQL_Error: Replicate_Ignore_Server_Ids: Master_Server_Id: 12001 Master_UUID: cfc81670-fca1-11e5-926d-0017fa0041c0 Master_Info_File: mysql.slave_master_info SQL_Delay: 0 SQL_Remaining_Delay: NULL Master_Retry_Count: 86400 Master_Bind: Last_IO_Error_Timestamp: Last_SQL_Error_Timestamp: Master_SSL_Crl: Master_SSL_Crlpath: Retrieved_Gtid_Set: Executed_Gtid_Set: Auto_Position: 0 Replicate_Rewrite_DB: Channel_Name: Master_TLS_Version: 1 row in set (0.00 sec) mysql show engine innodb status\G *************************** 1.

It may seem counterintuitive, but for some types of applications, the query cache, especially if set to be large, can reduce performance.

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