A bit on scaling chess.com's database
> One of things that has really helped our DB scale is the fact that we’ve moved a lot of sorting, merging, filtering from the DB into the code itself.This goes against everything I have learned until now. Maybe an experienced DBA can explain when moving stuff out of the database is helpful? I mean sorting, merging and filtering is the core discipline of a RDBMS and many, many man hours went into it. How and when can a custom version be better?