Gh-ost is a trigger-less online schema migration solution for MySQL. It functions similarly to other existing online-schema-change tools that create a ghost table to perform migration, but opts to not use triggers.


Instead Gh-ost uses the binary log stream to capture table changes and asynchronously applies them onto the ghost table.


You can read a detailed description of Gh-ost here, as well as check out the documentation here.

gh-ost general flow