Re: Attempt to consolidate reading of XLOG page
От | Antonin Houska |
---|---|
Тема | Re: Attempt to consolidate reading of XLOG page |
Дата | |
Msg-id | 50470.1574672520@antos обсуждение исходный текст |
Ответ на | Re: Attempt to consolidate reading of XLOG page (Alvaro Herrera <alvherre@2ndquadrant.com>) |
Ответы |
Re: Attempt to consolidate reading of XLOG page
|
Список | pgsql-hackers |
Alvaro Herrera <alvherre@2ndquadrant.com> wrote: > On 2019-Nov-22, Antonin Houska wrote: > > > As I pointed out in > > > > https://www.postgresql.org/message-id/88183.1574261429%40antos > > > > seg.ws_off only replaced readOff in XLogReaderState. So we should only update > > ws_off where readOff was updated before commit 709d003. This does happen in > > ReadPageInternal (see HEAD) and I see no reason for the final patch to update > > ws_off anywhere else. > > Oh you're right. > > I see no reason to leave ws_off. We can move that to XLogReaderState; I > did that here. We also need the offset in WALReadError, though, so I > added it there too. Conceptually it seems clearer to me this way. > > What do you think of the attached? It looks good to me. Attached is just a fix of a minor problem in error reporting that Michael pointed out earlier. > BTW I'm not clear what errors can pread()/pg_pread() report that do not > set errno. I think lines 1083/1084 of WALRead are spurious now. All I can say is that the existing calls of pg_pread() do not clear errno, so you may be right. I'd appreciate more background about the "partial read" that Michael mentions here: https://www.postgresql.org/message-id/20191125033048.GG37821%40paquier.xyz -- Antonin Houska Web: https://www.cybertec-postgresql.com
Вложения
В списке pgsql-hackers по дате отправления: