On Mon, May 17, 2021 at 01:46:37PM +0900, Masahiko Sawada wrote: > On Mon, Apr 5, 2021 at 3:31 PM Jaime Casanova > <jcasa...@systemguards.com.ec> wrote: > > > > Hi, > > > > When AV worker items where introduced 4 years ago, i was suggested that > > it could be used for other things like cleaning the pending list of GIN > > index when it reaches gin_pending_list_limit instead of making user > > visible operation pay the price. > > > > That never happened though. So, here is a little patch for that. > > Thank you for working on this. > > I like the idea of cleaning the GIN pending list using by autovacuum > work item. But with the patch, we request and skip the pending list > cleanup if the pending list size exceeds gin_pending_list_limit during > insertion. But autovacuum work items are executed after an autovacuum > runs. So if many insertions happen before executing the autovacuum > work item, we will end up greatly exceeding the threshold > (gin_pending_list_limit) and registering the same work item again and > again. Maybe we need something like a soft limit and a hard limit? > That is, if the pending list size exceeds the soft limit, we request > the work item. OTOH, if it exceeds the hard limit > (gin_pending_list_limit) we cleanup the pending list before insertion. > We might also need to have autovacuum work items ignore the work item > if the same work item with the same arguments is already registered. > In addition to that, I think we should avoid the work item for > cleaning the pending list from being executed if an autovacuum runs on > the gin index before executing the work item. >
Thanks for your comments on this. I have been working on a rebased version, but ENOTIME right now. Will mark this one as "Returned with feedback" and resubmit for november. -- Jaime Casanova Director de Servicios Profesionales SystemGuards - Consultores de PostgreSQL
