Re: [HACKERS] Binary Cursors, and the COPY command

Поиск
Список
Период
Сортировка
От Oliver Jowett
Тема Re: [HACKERS] Binary Cursors, and the COPY command
Дата
Msg-id 41063FFE.8030400@opencloud.com
обсуждение исходный текст
Ответ на Re: [HACKERS] Binary Cursors, and the COPY command  (Oliver Jowett <oliver@opencloud.com>)
Ответы Re: [HACKERS] Binary Cursors, and the COPY command  (Thomas Hallgren <thhal@mailblocks.com>)
Список pgsql-jdbc
Thomas Hallgren wrote:

> Well, the java.nio obviously :-)
>
> java.nio provides a java.nio.CharBuffer. A java.lang.StringBuffer is
> synchronized. The CharBuffer is not. Since the JDBC driver uses strings
> in a lot of places some code could be rewritten to increase performance.

I haven't seen the string manipulation to be much of a problem with the
current driver in the profiling I've done (it'll be quite application
specific though). And I'd have thought the stringbuffer monitors would
be essentially uncontended and cheap to enter. What are the hotspots you
see?

> And I think that Mark (pgsql@mohawksoft.com) has a point. 90% of all
> installations would get a performance boost if native byte order was
> used.

Well, not mine :) (x86 clients, sparc server, and the driver doesn't yet
use binary format in places where byte order matters anyway)

Also I am fairly suspicious about claims that native byte order will
make things go measurably faster. Do you have any profiling or
benchmarks to back that up? The low-level manipulation of protocol data
barely shows up on the profiles I've done.

-O

В списке pgsql-jdbc по дате отправления:

Предыдущее
От: Thomas Hallgren
Дата:
Сообщение: Re: [HACKERS] Binary Cursors, and the COPY command
Следующее
От: Thomas Hallgren
Дата:
Сообщение: Re: [HACKERS] Binary Cursors, and the COPY command