Is InnoDB sorting really THAT slow?

Question

I had all my tables in myISAM but the table level locking was starting to kill me when I had long running update jobs. I converted my primary tables over to InnoDB and now m

Answer 1

As written in Should you move from MyISAM to Innodb ? (which is pretty recent):

Innodb Needs Tuning As a final note about MyISAM to Innodb migration I should mention about Innodb tuning. Innodb needs tuning. Really. MyISAM for many applications can work well with defaults. I’ve seen hundreds of GB databases ran with MyISAM with default settings and it worked reasonably. Innodb needs resources and it will not work well with defaults a lot. Tuning MyISAM from defaults rarely gives more than 2-3 times gain while it can be as much as 10-50 times for Innodb tables in particular for write intensive workloads. Check here for details.

So, about MySQL Innodb Settings, the author wrote in Innodb Performance Optimization Basics:

The most important ones are:

innodb_buffer_pool_size 70-80% of memory is a safe bet. I set it to 12G on 16GB box.

UPDATE: If you’re looking for more details, check out detailed guide on tuning innodb buffer pool

innodb_log_file_size – This depends on your recovery speed needs but 256M seems to be a good balance between reasonable recovery time and good performance

innodb_log_buffer_size=4M 4M is good for most cases unless you’re piping large blobs to Innodb in this case increase it a bit.

innodb_flush_log_at_trx_commit=2 If you’re not concern about ACID and can loose transactions for last second or two in case of full OS crash than set this value. It can dramatic effect especially on a lot of short write transactions.

innodb_thread_concurrency=8 Even with current Innodb Scalability Fixes having limited concurrency helps. The actual number may be higher or lower depending on your application and default which is 8 is decent start

innodb_flush_method=O_DIRECT Avoid double buffering and reduce swap pressure, in most cases this setting improves performance. Though be careful if you do not have battery backed up RAID cache as when write IO may suffer.

innodb_file_per_table – If you do not have too many tables use this option, so you will not have uncontrolled innodb main tablespace growth which you can’t reclaim. This option was added in MySQL 4.1 and now stable enough to use.

Also check if your application can run in READ-COMMITED isolation mode – if it does – set it to be default as transaction-isolation=READ-COMMITTED. This option has some performance benefits, especially in locking in 5.0 and even more to come with MySQL 5.1 and row level replication.

Just for the record, the people behind mysqlperformanceblog.com ran a benchmark comparing Falcon, MyISAM and InnoDB. The benchmark was really supposed to be highlighting Falcon, except it was InnoDB that won the day, topping both Falcon and MyISAM in queries per second for almost every test: InnoDB vs MyISAM vs Falcon benchmarks – part 1.