April 18, 2014

Schema changes – what’s new in MySQL 5.6?

Among many of the improvements you can enjoy in MySQL 5.6, there is one that addresses a huge operational problem that most DBAs and System Administrators encounter in their life: schema changes. While it is usually not a problem for small tables or those in early stages of product life cycle, schema changes become a […]

Zero-downtime schema changes webinar recording

The recording and slides for my webinar on zero-downtime schema changes with MySQL are available now. Don’t miss Vadim’s webinar tomorrow!

Zero-Downtime Schema Changes In MySQL

The recording of yesterday’s webinar, as well as a PDF of my slide deck, is now available. You can watch the recording and get the slides here. I got a lot of questions, and did not have enough time to answer all of them, so let me try to answer some of the remaining questions […]

Integrating pt-online-schema-change with a Scripted Deployment

Recently, I helped a client that was having issues with deployments causing locking in their production databases.  At a high level, the two key components used in the environment were: Capistrano (scripted deployments) [website] Liquibase (database version control) [website] At a high level, they currently used a CLI call to Liquibase as a sub-task within […]

pt-online-schema-change and binlog_format

Statement-based or row-based, or mixed?  We’ve all seen this discussed at length so I’m not trying to rehash tired arguments.  At a high level, the difference is simple: Statement based replication (SBR) replicates the SQL statements to the slave to be replayed Row based replication (RBR) replicates the actual rows changed to the slave to […]

Implementing SchemaSpy in your MySQL environment

Lately I have been working with a set of customers on a longer term basis which has given me time to explore new tools using their environments.  One tool that I am finding very helpful is called SchemaSpy. SchemaSpy is a Java-based tool (requires Java 5 or higher) that analyzes the metadata of a schema in […]

MySQL 5.6 vs MySQL 5.5 and the Star Schema Benchmark

So far most of the benchmarks posted about MySQL 5.6 use the sysbench OLTP workload.  I wanted to test a set of queries which, unlike sysbench, utilize joins.  I also wanted an easily reproducible set of data which is more rich than the simple sysbench table.  The Star Schema Benchmark (SSB) seems ideal for this. […]

Knowing what pt-online-schema-change will do

pt-online-schema-change is simple to use, but internally it is complex.  Baron’s webinar about pt-online-schema-change hinted at several of the tool’s complexities.  Consequently, users often want to know before making changes what pt-online-schema-change will do when it runs.  The tool has two options to help answer this question: –dry-run and –print. When ran with –dry-run and –print, pt-online-schema-change changes nothing […]

Review of MySQL 5.6 Defaults Changes

James Day just posted the great summary of defaults changes in MySQL 5.6 compared to MySQL 5.5 In general there are a lot of good changes and many defaults are now computed instead of hardcoded. Though some of changes are rather puzzling for me. Lets go over them: back_log = 50 + ( max_connections / […]

Percona Toolkit 2.1 with New Online Schema Change Tool

I’m proud to announce the GA release of version 2.1 of Percona Toolkit. Percona Toolkit is the essential suite of administrative tools for MySQL. With this release we introduce a new version of pt-online-schema-change, a tool that enables you to ALTER large tables with no blocking or downtime. As you know, MySQL locks tables for […]