Hi! On Tue, Apr 29, 2014 at 2:34 PM, Костя Кузнецов <chapae...@yandex.ru> wrote:
> There is a task "Sequential disk access during VACUUM for GiST/GIN " in > list GSOC14. > Nobody is working on this task? > I didn't hear anybody is working on it. > Do I understand this task correctly? > I must recode gistbulkdelete. > GistBDItem *stack is must have items with sequential blkno as possible. > Yes, make gistbulkdelete and ginbulkdelete access disk sequentially while now tree is traversed in logical order. So these functions need to be completely reworked: I'm not sure GistBDItem will survive :) The challenge is concurrency. Vacuum shouldn't block concurrent readers and writers. You can see btbulkdelete which supports sequential disk access now. > I have a question: > where are access to disk in this function? ReadBufferExtended? > Yes, this function read buffer to shared memory (if it isn't already) and "pins" it. ------ With best regards, Alexander Korotkov.
