… it is a lot larger problems with MySQL 5.5 with addition of user variables, stored procedures, prepared statements etc which can… of resources prepared statements take on server. There is no comparable variables of how many user variables are allocated (and how much memory… you close connection. In Percona Server you can do better as you can query temporary tables too: mysql> select sum(data_length+index…
Post: Introducing the pmp-check-mysql-status Nagios Plugin
March 29, 2012 By Leave a Comment
…variables. This is the pmp-check-mysql-status plugin, which can perform computations on status variables. By default, I recommend using it only for two purposes: Check whether the Uptime variable is too small, indicating the server…
Post: InnoDB's gap locks
March 27, 2012 By 15 Comments
…. This makes reads consistent and therefore makes the replication between servers consistent. If you execute SELECT * FROM id > 1000 FOR UPDATE… lock(s), undo log entries 1 MySQL thread id 3, OS thread handle 0x7f84a78ba700, query id 163 localhost msandbox TABLE LOCK table… that the second one is a global variable that affects all sessions and needs a server restart to change its value. Both…
Post: Should we give a MySQL Query Cache a second chance ?
April 10, 2011 By 63 Comments
…query result which is up to 60 stable. We can also get query_cache_ttl as session variable…queries, for which tracking exact rows used from query syntax may be hard. Query Cache Storage Engines MySQL Query Cache now stores queries…
Post: Can we improve MySQL variable handling ?
February 18, 2012 By 8 Comments
MySQL Settings (also known as Server Variables) have interesting property. When you set variable in running server this change is not persisted… SELECT syntax to ease querying of variable global value Right now I can select: mysql> select @@global.sort_buffer_size; +—————————+ |…
Post: How Percona does a MySQL Performance Audit
November 24, 2008 By 17 Comments
…_tables, I’ll paste in mysql> show global variables like ‘%table_size%’; +———————+———–+ | Variable_name | Value | +———————+———–+ | max_heap_table_… query log output. The stock MySQL server‘s limitation of one-second granularity makes it hide problem queries …
Post: Percona Server 5.5.10 (Release Candidate)
April 4, 2011 By 4 Comments
…) Old system variable slow_query_log_microseconds_timestamp was renamed to slow_query_log_timestamp_precision. (Oleg Tsarev) Old system variable use_global_log… MySQL 5.0 or Percona Server versions prior to 5.1.7 could crash the server. (Yasufumi Kinoshita) MySQL bugs 56433 and 51325 – These MySQL…
Post: Ultimate MySQL variable and status reference list
January 8, 2011 By 4 Comments
…MySQL manual, especially the option and variable reference table. But just as frequently, I want to look up blog posts on variables…server…
Post: Identifying the load with the help of pt-query-digest and Percona Server
December 29, 2011 By 3 Comments
… normally do is set the variable log_slow_verbosity to ‘full’, this variable is available in Percona Server and allows us to log… you were using the vanilla MySQL server, you would see an entry like this in the slow query log: # Time: 111229 3:02… query is 270.35k, which is not much considering the fact that tmp_tbl_size variable is set to 32M on the server…
Post: MySQL Server Variables - SQL layer or Storage Engine specific.
June 8, 2006 By 14 Comments
MySQL Server has tons of variables which may be adjusted to change behavior or for performance … for Innodb. tmp_table_size This variable specifies maximum size implicit temporary table (created during query execution automatically) will grow as MEMORY…
