高健 wrote: > I have one question about checkponint . That is : can checkpoint be parallel? > > It is said that checkpoint will be activated according to either conditions: > > 1)After last checkpoint, checkpoint_timeout seconds passed. > > 2)When shared_buffers memory above checkpoint_segments size is filled with data. > > My experience is that : > > There is only one checkpoint process there and works, and even when there are many data created during > transactions, > > There will also be only one checkpoint process deal with it > > (maybe background writer or some other server process will deal it)? It would not make sense to have more than one checkpoint going on at the same time; it is a point at which recovery can begin. > And also, I think when the above 1) or 2) activated checkpoint , > > after the checkpoint data creation, then the 1) and 2) value will be to zero and calculated again. > > So I think that checkpoint will not be created parallel. > > Is my understanding right? Yes. > And if there are some official documentation from www.postgresql.org or somewhere else, I'll be very > appreciative. http://www.postgresql.org/docs/9.3/static/wal-configuration.html "A checkpoint is begun every checkpoint_segments log segments, or every checkpoint_timeout seconds, whichever comes first." Yours, Laurenz Albe -- Sent via pgsql-general mailing list (pgsql-general@xxxxxxxxxxxxxx) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-general
