Re: 8.3 / 8.2.6 restore comparison
От | Joshua D. Drake |
---|---|
Тема | Re: 8.3 / 8.2.6 restore comparison |
Дата | |
Msg-id | 47C1B5F8.9090708@commandprompt.com обсуждение исходный текст |
Ответ на | Re: 8.3 / 8.2.6 restore comparison (Andrew Dunstan <andrew@dunslane.net>) |
Список | pgsql-hackers |
Andrew Dunstan wrote: > > > Joshua D. Drake wrote: >> Heikki Linnakangas wrote: >>> >>> We read 64 KB at a time, and then CopyReadLineText returns one line >>> at a time from that buffer. >> >> O.k. I am sure I am oversimplifying things but why are we returning >> one line at a time? That reads expensive to me. Just following the >> general, don't do inserts one at a time, do them in batch idea for >> example. > > Quite simply because one line corresponds to one record. And yes, I > believe you are oversimplifying, or under several misapprehensions about > what can be done at this level. Well I find without questioning, I won't get the answers so :). > It would be simple enough to change. Try it and see if it actually makes > a difference. All you have to change is the define of RAW_BUF_SIZE. > Fair enough. May I assume this is the only place I need to change it? http://doxygen.postgresql.org/backend_2commands_2copy_8c-source.html#l00158 >> It looks like CopyReadAttributesText is used as part of the column >> breakup. It also appears that this happens "before" insert right? So >> if that is the case we are going to pay an additional penalty on the >> data checking. >> > > What? I don't understand what you are talking about. Data checking on insert to the DB itself. I have no doubt that I may be wrong on this. Joshua D. Drake
В списке pgsql-hackers по дате отправления: