gh-ost 1.0.42 released: JSON support, optimizations

September 14, 2017

gh-ost 1.0.42 is released and available for download.


MySQL 5.7's JSON data type is now supported.

There is a soft-limitation, that your JSON may not be part of your PRIMARY KEY. Currently this isn't even supported by MySQL anyhow.


Two noteworthy changes are:

  • Client side prepared statements reduce network traffic and round trips to the server.
  • Range query iteration avoids creating temporary tables and filesorting.

We're not running benchmarks at this time to observe performance gains.


More tests validating 5.7 compatibility (at this time GitHub runs MySQL 5.7 in production).


Many other changes included.

We are grateful for all community feedback in form of open Issues, Pull Requests and questions!

gh-ost is authored by GitHub. It is free and open source and is available under the MIT license.


In two weeks time, Jonah Berquist will present gh-ost: Triggerless, Painless, Trusted Online Schema Migrations at Percona Live, Dublin.

Tom Krouper and myself will present MySQL Infrastructure Testing Automation at GitHub, where, among other things, we describe how we test gh-ost in production.

Powered by Wordpress and MySQL. Theme by