clean up indexes in grouper

I would like to discuss each index we have in grouper, decide is we need to keep, change, or remove it.
Can we discuss at some call?

e.g. we have a non-unique index on membership create time... doesnt seem necessary. Lets discuss.

With the new DDL strategy we can easily adjust these.

I can document the non-obvious ones (or all of them), so we know later on why we have them.

Do we need create_source (and modify source) columns anymore if the creator_id is the member_id?

Should name and displayName for stems be 255 only?

Thanks,
Chris