… data with SQL statements. I wanted to see how fast MyISAM vs. MonetDB would interpret really large INSERT statements, the kind…. Here’s a graph of the times (smaller is better): MyISAM took 88 seconds, MonetDB took 200, and Infobright took 486… size of the resulting table on disk (smaller is better): MyISAM is 787MB, MonetDB is 791MB, and Infobright is 317MB. Next…
Post: To pack or not to pack - MyISAM Key compression
May 13, 2006 By 4 Comments
…: Forward range/index scan will be fast (read_next) as MyISAM will remember previous position and will not uncompress block from… Reverse range/index scan will be slower (read_prev) as MyISAM will have to start bock uncompressing over to get previous…) NOT NULL default ”, KEY `c` (`c`), KEY `id` (`id`) ) ENGINE=MyISAM Index size: PACK_KEYS=DEFAULT – 1550K PACK_KEYS=1 – 1453K…
Post: MyISAM mmap feature (5.1)
May 26, 2006 By 10 Comments
As you know MyISAM does not cache data, only indexes. MyISAM assumes OS cache is good enough and uses pread/pwrite …: memory mapping for the datafiles. That can be enabled by –myisam_use_mmap=1 startup option. In this case instead of systems call MyISAM will use memcpy function. There is a memory addressing limit…
Post: Webinar: MyISAM to InnoDB migration
November 8, 2010 By 4 Comments
Register now for a free Percona webinar about migrating your MyISAM databases to InnoDB. Save the date: Dec 1, 2010 at… such webinar. With the change in default storage engine from MyISAM to InnoDB in the upcoming MySQL 5.5 release, we… How to decide whether you should switch, or stay on MyISAM Matt Yonkovit will cover those and many more topics. Register…
Post: Beware of MyISAM Key Cache mutex contention
August 12, 2008 By 10 Comments
Today I was working with the client loading data to MyISAM tables at very high rate. Hundreds of millions rows are… work done than one would hope. As we already discussed MyISAM key cache has serious mutex contention issue as there is… copied from key_cache to the thread local space. Happily MyISAM allows you to create multiple key caches . We use “keycache…
Post: MyISAM concurrent insert
June 13, 2006 By 12 Comments
Arjen posted a good note about MyISAM concurrent-insert features, though I should mention concurrent-insert can … user-space (Solaris) or kernel-space (Linux). Some results for MyISAM table, query SELECT id FROM sbtest WHERE id BETWEEN N… than disabling concurrent-insert with –skip-concurrent-insert can improve MyISAM performance. As I said the reason of bad scalability is…
Post: Getting annoyed with MyISAM multiple key caches.
May 1, 2009 By 11 Comments
… great way to get CPU scalability if you’re using MyISAM. It is however very annoying – this feature really looks half… is not documented. I’m not sure how relevant is MyISAM with MariaDB on a way but this is surely sad…
Post: MySQL MyISAM Active Active Clustering - looking for trouble ?
March 15, 2007 By 4 Comments
… saying you can use MySQL with Active Active Clustering and MyISAM tables if you follow certain rules like enabling external locking… was not repairing corrupted tables in this configuration even if myisam_repair is set. Space Saving ? As I mentioned replication can…
Post: Doing Re-run of Migrating MyISAM to Innodb Webinar
December 1, 2010 By 9 Comments
… what happened to me). As result we have scheduled Migrating MyISAM to Innodb webinar to run again on Tuesday, December 7…
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 …
