…ones. Concurrency. MyISAM uses table locks and has concurrent inserts which can go concurrently with selects. This is sometimes presented as great concurrency for …crashes). You can use multiple of cache tables to avoid concurrency issues. Temporary tables used in batch processing and other means …
Post: Should you move from MyISAM to Innodb ?
January 12, 2009 By 59 Comments
… close to memory size), generally slower writes, slower blob handling, concurrency issues, problems dealing with very large number of tables, slow data… for you when you’re running MyISAM but instantly break upon upgrading to Innodb. Features The MyISAM features which forbid moving to…
Post: Concatenating MyISAM files
November 19, 2012 By 5 Comments
… of a large read-only InnoDB database to MyISAM (eventually packed). The only issue was that for one of the table, we… clearly the lack of concurrency on the read part from InnoDB and then the key management for MyISAM. The server has many… was easy to add more concurrency so I kicked off, from a script, insertions into 16 identical MyISAM files for distinct parts…
Post: MyISAM Scalability and Innodb, Falcon Benchmarks
October 12, 2007 By 10 Comments
… 121 16 138 As you see running 2-4 threads concurrently we get result by 30% worse than with 1 thread… than 2x in peak which happens to be at 4 concurrent threads. So there is still work to do in addition… comparison of MyISAM Innodb and Falcon results in the graphical form: I’ve created bug, for MyISAM key cache contention issue and lets…
Post: Innodb Table Locks
July 31, 2012 By 4 Comments
…in “IX” in SHOW ENGINE INNODB STATUS while concurrent updates to this table will be prevented until…important difference between MyISAM and Innodb when it comes to Table Level Locks. For MyISAM tables running UPDATE…by DDL operations. If you’re having locking issues with Innodb chances are it is row …
Comment: Why MySQL could be slow with large tables ?
June 20, 2007 By 141 Comments
…=24M read_buffer_size=9M max_connect_errors=10 thread_concurrency=4 myisam_sort_buffer_size=950M character-set-server=utf8 default…_slow_queries=/var/log/mysql-slow.log sql-mode=TRADITIONAL concurrent_insert=2 low_priority_updates=1 The problem was that… fraction of INSERTs and UPDATEs)? We explored a bunch of issues including questioning our hardware and our system administrators 
When we…
Post: Paul McCullagh answers your questions about PBXT
November 20, 2009 By 2 Comments
… architecture makes performance characteristics different to both MyISAM and InnoDB/XtraDB. Tests show that PBXT’… are consecutive) but this can become an issue if millions of rows are selected in … key acceptance criteria are things like backup, concurrency, ACID compliance and crash recovery. As a …
Comment: Beware of MyISAM Key Cache mutex contention
January 12, 2010 By 10 Comments
… increased the concurrency!) I put under monitoring all the parameters I could think of, and mysql processes showed in issue periods multiple… wastes 90% time in rounding-robin and cannot manage the concurrent access at a shared resource in a more efficient way… you think of Sphinx to substitute the fulltext search on MyISAM table? Peter, I owe you a beer, big one. Claudio
Post: Innodb Performance Optimization Basics
November 1, 2007 By 75 Comments
… even just two Quad Core CPUs scalability issues can be observed on many workloads. …transactions. innodb_thread_concurrency=8 Even with current Innodb Scalability Fixes having limited concurrency helps. The… tuning for Innodb Especially when coming from MyISAM background there would be some changes …
Comment: table_cache negative scalability
April 14, 2010 By 23 Comments
… MyISAM and InnoDB table cache? 3) Would converting the MyISAM tables to InnoDB fix or help the os ulimit max open tables issue…_table_size = 100M query_cache_size = 100M default_table_type = MYISAM log_long_format # Innodb innodb_status_file = 1 innodb_file…_size = 256M innodb_log_files_in_group = 2 innodb_thread_concurrency = 16 innodb_open_files = 20000 innodb_flush_method = O_DIRECT…
