Hey,
I wrote up a little design spike for a bunch of code needed for the store schema update functionality. This is nothing big or out of the ordinary [0]. Since I am only continuing with this code later this week, and no real implementation has been done so far, this commit now lends itself well to a design level review.
https://gerrit.wikimedia.org/r/#/c/81254/3/src/TableDefinitionReader.php
[0] Someone please suggest writing a formal RFC, have 5 calls about it, a dedicated architecture review, a dedicated security review, and perhaps its own mailing list.