Re: warm standby server stops doingcheckpointsafterawhile
От | Teodor Sigaev |
---|---|
Тема | Re: warm standby server stops doingcheckpointsafterawhile |
Дата | |
Msg-id | 4663E40E.5070106@sigaev.ru обсуждение исходный текст |
Ответ на | Re: warm standby server stops doingcheckpointsafterawhile ("Simon Riggs" <simon@2ndquadrant.com>) |
Список | pgsql-general |
> 1. After a certain point, consecutive GIN index splits cause a problem. > The new RHS block numbers are consecutive from 111780+ That's newly created page. Splitted page might have any number > > 2. The incomplete splits stay around indefinitely after creation and we > aren't trying to remove the wrong split at any point. We're either never > creating an xlog record, or we are ignoring it in recovery, or we are > somehow making multiple entries then not removing all of them. Agreed > 3. The root seems to move, which isn't what I personally was expecting > to see. It seems root refers to the highest parent involved in the > split. root in this context means parent of splitted page. Actually, there is a lot of B-tree in GIN, see http://www.sigaev.ru/gin/GinStructure.pdf > > 4. We're writing lots of redo in between failed page splits. So *almost* > everything is working correctly. > > 5. This starts to happen when we have very large indexes. This may be > coincidental but the first relation file is fairly full (900+ MB). Yes. It seems to me that conditions of error are very rare and B-tree over ItemPointers (second level of GIN) has a big capacity, 1000+ items per page. So, splits occur rather rare. -- Teodor Sigaev E-mail: teodor@sigaev.ru WWW: http://www.sigaev.ru/
В списке pgsql-general по дате отправления: