On 15/09/2017 12:51, Daniel Kinzler wrote:
I'm working on the database schema for Multi-Content-Revisions (MCR)
like to get rid of the rev_sha1 field:
Maintaining revision hashes (the rev_sha1 field) is expensive, and becomes more
expensive with MCR. With multiple content objects per revision, we need to track
the hash for each slot, and then re-calculate the sha1 for each revision.
That was introduced by Aaron Schulz. The purpose is to have them pre
computed since that is quite expensive to have to do it on million of rows.
A use case was to easily detect reverts.
See for reference:
I guess Aaron Halfaker, Brion Vibber, Aaron Schulz would have some
insights about it.