Re: XML path function

On Jan 9, 2008 6:00 PM, x asasaxax <xanaruto@gmail.com> wrote:
> My Postgre version its the 8.2. I´ve reached to do the path i wanted, but
> when i do a explain analyze on the select it return 500 miliseconds. Is this
> a good search? Is there a way to slow down this time with postgre 8.3? What
> is a good time for xml xpath´s?

Unfortunately, this is the normal speed. The reason is that Postgres
does full XML parsing and XPath evaluation at runtume.

If you use

SELECT <columns list>
FROM <table>
WHERE <xpath function> = <constant>,

then functional indexes over xpath function may help. Also, you could
use tsearch2 + functional XPath indexes to index text data from your
XML, if you have corresponding needs.

Unfortunately, that is almost all you can do speeding up your XPath
queries at the moment, and in terms of performance there is no any
major improvements in 8.3 either.

--
Nikolay Samokhvalov  <nikolay@samokhvalov.com>
http://nikolay.samokhvalov.com

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