… TABLES WITH READ LOCK to temporary make MySQL read only. In many cases the period for which server has to be made read only is very short, just few seconds, yet the impact of FLUSH TABLES WITH READ LOCK can be…) Reads though would not be blocked, ie there is no MYISAM like table lock priority problem with pending WRITE query blocks any READ…
Comment: How FLUSH TABLES WITH READ LOCK works with Innodb Tables
March 23, 2012 By 20 Comments
Shlomi, Yes setting server read only would be solution. Though it is still too bad setting server read only…. When we speak about Innodb… not really need it. What we need is MyISAM tables flushed and read only so they can be copied and Innodb tables can…
Post: Using MyISAM in production
June 17, 2006 By 35 Comments
… view on using MyISAM in production. For me it is not only about table locks. Table locks is only one of MyISAM limitations you…: Log tables. Now Archive storage engine can be even better. Read only data, especially packed with myisampack. This can’t be corrupted… can start over and most of the time data is read only anyway. Tables which contain data which is quick to regenerate…
Post: How fast is FLUSH TABLES WITH READ LOCK?
April 24, 2010 By 28 Comments
… this time, the server will get completely blocked (not just read-only!) To understand why, let’s look at what this command…. As a result, a system that has a lot of MyISAM data might have a lot of dirty blocks in the… TABLES WITH READ LOCK will complete quickly. In some cases, it is unavoidable. This includes backing up a mixture of MyISAM and…
Post: Using Multiple Key Caches for MyISAM Scalability
November 26, 2008 By 8 Comments
I have written before – MyISAM Does Not Scale, or it does quite well – two main … on the KeyCache. Table Locks are not the issue for Read Only workload and write intensive workloads can be dealt with by… t.table_name in (“a”,”b”)) + (rows_read+rows_changed)/(select sum(rows_read+rows_changed) from information_schema.table_statistics where…
Post: InnoDB vs MyISAM vs Falcon benchmarks - part 1
January 8, 2007 By 117 Comments
… to InnoDB and MyISAM. The second goal of benchmark was a popular myth that MyISAM is faster than InnoDB in reads, as InnoDB… is similar to previous READ_KEY_POINT with only different the values of accessed column is stored in key. MyISAM and InnoDB handle… and %d MyISAM scales good here, because of access only to key column and ‘pread’ syscall is not used. READ_KEY_RANGE Query…
Post: MySQL Server Variables - SQL layer or Storage Engine specific.
June 8, 2006 By 14 Comments
… applies to MYISAM and MEMORY tables. preload_buffer_size – Buffer used for Key preloading, which works for MYISAM tables only. read_buffer_size, read_rnd_buffer_size – Variables used as read buffer for MyISAM tables for Full Table Scan (read_buffer) and for reading…
Post: What exactly is read_rnd_buffer_size
July 24, 2007 By 4 Comments
… very similar to read_buffer_size which is currently only used by MyISAM tables I thought read_rnd_buffer_size is also MyISAM only. But talking to Monty today I learned it is not the case. read_rnd_buffer can be used for All storage engines not only by MyISAM. It is used for some sorts to optimally read rows…
Post: Ultimate MySQL variable and status reference list
January 8, 2011 By 4 Comments
….commanual myisam_recoverblogpercona.commanual myisam_recover_optionsblogpercona.commanual myisam_recover_optionsblogpercona.commanual myisam_repair_threadsblogpercona.commanual myisam_sort_buffer_sizeblogpercona.commanual myisam_stats_methodblogpercona.commanual myisam_use_mmapblogpercona.commanual named_pipeblogpercona.commanual net_buffer_lengthblogpercona.commanual net_read_timeoutblogpercona…
Post: MyISAM Scalability and Innodb, Falcon Benchmarks
October 12, 2007 By 10 Comments
… NULL, PRIMARY KEY (`id`), KEY `val` (`val`) ) ENGINE=MyISAM AUTO_INCREMENT=4097 Table t1 contains about 260… worse than with 1 thread, although it’s only simple select query which should be executed without…copied to processing thread local storage on Key Read Request. This lock is per key cache so…
