We need to be able to store longer revision comments in the database in order to accommodate non-Latin languages. (See T6715 for background.) Two approaches have been proposed that seem more or less viable. We need to decide which approach is best.
Approach #1 is to just increase the existing rev_comments field from tinyblob (255 bytes) to varbinary(767), but keep a 255 character limit on the client-side. The 255 character limit means that this should have little to no effect on Latin language wikis, but it could increase table bloating in the long-term for non-Latin wikis. This solution is relatively easy to implement.
Approach #2 is to gradually move revision comments to a separate look-up table. This approach is described at T6715#1735048 and T6715#1735257. This approach will help reduce bloating of the revision table and put us in a better position for the long-term. However, it will require dedicated work over many months to implement and will not be as backwards compatible as approach #1 (for example, it may break some Tool Labs tools).
It is also possible to pursue both approaches: #1 in the short term and #2 in the long-term.
What do people think is the best way forward?