Re: Understanding GIN posting trees

Heikki Linnakangas <heikki.linnakangas@enterprisedb.com> writes:
> Why is the posting tree a tree? AFAICS, we never search it using the 
> TID, it's always scanned in whole. It would be simpler to store the TIDs 
> in a posting list in no particular order. This could potentially make 
> insertions cheaper, as you could just append to the last posting list 
> page for the key, instead of traversing the posting tree to a particular 
> location. You could also pack the tids denser, as you wouldn't need to 
> reserve free space for additions in the middle.

Surely VACUUM would like to search it by TID for deletion purposes?
        regards, tom lane