Re: best way to fetch next/prev record based on index

Поиск
Список
Период
Сортировка
От Tom Lane
Тема Re: best way to fetch next/prev record based on index
Дата
Msg-id 16242.1091126497@sss.pgh.pa.us
обсуждение исходный текст
Ответ на Re: best way to fetch next/prev record based on index  ("Merlin Moncure" <merlin.moncure@rcsonline.com>)
Список pgsql-performance
"Merlin Moncure" <merlin.moncure@rcsonline.com> writes:
> I would much rather see postgres 'get' (a,b,c) > (a1,
> b1, c1)...if there is even a chance this is possible, I'll direct my
> efforts there.

For the ISAM context this whole discussion is kinda moot, because you
really don't want to have to plan and execute a fairly expensive query
for every record fetch.  If we had all the improvements discussed, it
would be a reasonably cheap operation by the standards of "execute
an independent query", but by the standards of "fetch next record
in my query" it'll still suck.  (Using PREPARE might help, but only
somewhat.)

It strikes me that what you really want for ISAM is to improve the
cursor mechanism so it will do the things you need.  I'm not sure
what's involved, but let's talk about that angle for a bit.

            regards, tom lane

В списке pgsql-performance по дате отправления:

Предыдущее
От: "Merlin Moncure"
Дата:
Сообщение: Re: best way to fetch next/prev record based on index
Следующее
От: Greg Stark
Дата:
Сообщение: Re: best way to fetch next/prev record based on index