Percona's MySQL & InnoDB performance and scalability blog
I’ve never been a very big fan of MyISAM; I would argue that in most situations, any possible advantages to using MyISAM are far outweighed by the potential disadvantages and the strengths of InnoDB. However, up until MySQL 5.6, MyISAM was the only storage engine with support for full-text search (FTS). And I’ve encountered many [...]
One of the most important features of InnoDB is the row level locking. This feature provides better concurrency under heavy write load but needs additional precautions to avoid phantom reads and to get a consistent Statement based replication. To accomplish that, row level locking databases also acquire gap locks. What is a Phantom Read A [...]
Statement based replication writes the queries that modify data in the Binary Log to replicate them on the slave or to use it as a PITR recovery. Here we will see what is the behavior of the MySQL when it needs to log “not usual” queries like Events, Functions, Stored Procedures, Local Variables, etc. We’ll [...]
Percona Live London starts on Monday, so this is the last in the series of free-Percona-Live tickets we’ll give away. But first — have you ever wondered what servers are in your MySQL replication hierarchy? We have, too. As consultants, a lot of times we need to get a quick overview of the whole replication [...]
Infobright and InnoDB AMI images are now available There are now demonstration AMI images for Shard-Query. Each image comes pre-loaded with the data used in the previous Shard-Query blog post. The data in the each image is split into 20 “shards”. This blog post will refer to an EC2 instances as a node from here [...]
When I did NDB Cluster engagements, it happened a few time that I had to cover the NDB API. Once, a customer asked an example on how to perform a simple scan. Remembering that some examples are within the NDB source tree, under ./storage/ndb/ndbapi-examples/ and I decided to take a look, why writing something when [...]
I vaguely recall a couple of blog posts recently asking something like “what’s the formula to compute mysqld’s worst-case maximum memory usage?” Various formulas are in wide use, but none of them is fully correct. Here’s why: you can’t write an equation for it.
A while ago I wrote about how to make MySQL replication reliable, part of which is to eliminate temporary tables. The idea is this: if a slave is stopped (or crashed) while a temporary table is open and is then restarted, the temporary table doesn’t exist anymore, and the slave will have problems trying to [...]
What MySQL honestly was never good at is giving good helpful error messages. Start with basics for example – The error message in case of syntax error gives you information about tokens near by but little details:
1 2 | mysql> select * from user oder by pwd; ERROR 1064 (42000): You have an error in your SQL syntax; check the manual that corresponds to your MySQL server version for the right syntax to use near 'by pwd' at line 1 |
It would be much better if MySQL would give error give exact position of error (with complex [...]
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