Re: break table into portions for writing to separate files

Поиск
Список
Период
Сортировка
От Seb
Тема Re: break table into portions for writing to separate files
Дата
Msg-id 87wqe5nt6c.fsf@net82.ceos.umanitoba.ca
обсуждение исходный текст
Ответ на break table into portions for writing to separate files  (Seb <spluque@gmail.com>)
Ответы Re: break table into portions for writing to separate files
Список pgsql-general
On Thu, 1 May 2014 22:17:24 +0200,
Szymon Guz <mabewlun@gmail.com> wrote:

> On 1 May 2014 21:01, Seb <spluque@gmail.com> wrote:
>     On Thu, 1 May 2014 20:22:26 +0200,
>     Szymon Guz <mabewlun@gmail.com> wrote:

>> Hi, several Gb is about 1GB, that's not too much. In case you meant
>> 'several GB', that shouldn't be a problem as well.

>     Sorry, I meant several GB.  Although that may not be a problem for
> PostgreSQL, it is for post-processing the output file with other
> tools.

>> The first thing I'd do would be creating an index on the column used
>> for dividing the data. Then I'd just use the command COPY with a
>> proper select to save the data to a file.

>     I should have mentioned that this is quite a complex view (not a
> table), which joins several other views of similar complexity.  I'm
> not sure whether indexes are useful/feasible in this case.  I'll
> investigate.

> Yes, indexes can be used to speed up the view as well. Such a view is
> nothing more than just a query.

Help for CREATE INDEX says that its target should be a table or
materialized view, so I'm guessing you mean indexes on the relevant
fields of the underlying tables.  In that case, I already have indexes
on those, especially the timestamp fields which are the ones that are
used for the heavy query work.

Thanks,

--
Seb

В списке pgsql-general по дате отправления:

Предыдущее
От: Szymon Guz
Дата:
Сообщение: Re: break table into portions for writing to separate files
Следующее
От: Szymon Guz
Дата:
Сообщение: Re: break table into portions for writing to separate files