Thread: postgres and xquery

postgres and xquery

From

kristian kvilekval

Date:

14 May 2013, 07:31:20

I saw on the mailing list that back in 2010 there was some discussion of using Zorba to add xquery capabilities to postgres. I was wondering if any progress had been made on this and what the current interest levels of supporting xml in postgres are?

Thanks,

Kris

Re: postgres and xquery

From

John R Pierce

Date:

14 May 2013, 08:29:35

On 5/13/2013 9:31 PM, kristian kvilekval wrote:
>   I saw on the mailing list that back in 2010 there was some
> discussion of using Zorba to add xquery capabilities to postgres.  I
> was wondering if  any progress had been made on this and what the
> current interest levels of supporting xml in postgres are?


postgres gained fairly extensive handling of xml data a few versions
ago, and as that became stable, it seemed like all the buzz was moving
on to json.



--
john r pierce                                      37N 122W
somewhere on the middle of the left coast

Re: postgres and xquery

From

John R Pierce

Date:

14 May 2013, 10:37:34

On 5/13/2013 9:31 PM, kristian kvilekval wrote:
>   I saw on the mailing list that back in 2010 there was some
> discussion of using Zorba to add xquery capabilities to postgres.  I
> was wondering if  any progress had been made on this and what the
> current interest levels of supporting xml in postgres are?

Zorba has a JDBC database interface, and JDBC can talk to postgres.
this would let you use zorba to query a postgres database via xQuery.
isn't that what you want?


--
john r pierce                                      37N 122W
somewhere on the middle of the left coast

Re: postgres and xquery

From

kristian kvilekval

Date:

14 May 2013, 17:48:47

I was really hoping to see be able to store several ten's of millions XML documents in postgres, but I would also like to use Xquery to retrieve results. Back in 2010 there was some mailing list discussion about using integrating the xquery processor of zorba into postgres. I was trying to gauge the interest level and if anybody had attempted it. As you say, JSON has stolen all the thunder, and in fact the Zorba people have worked on JSONiq (an xquery processor for JSON data structures), but our project uses XML. We like the flexibility you get with Xquery and I am looking around for some solutions.

On Tue, May 14, 2013 at 12:37 AM, John R Pierce <pierce@hogranch.com> wrote:

On 5/13/2013 9:31 PM, kristian kvilekval wrote:
I saw on the mailing list that back in 2010 there was some discussion of using Zorba to add xquery capabilities to postgres. I was wondering if any progress had been made on this and what the current interest levels of supporting xml in postgres are?

Zorba has a JDBC database interface, and JDBC can talk to postgres. this would let you use zorba to query a postgres database via xQuery. isn't that what you want?

--
john r pierce 37N 122W
somewhere on the middle of the left coast

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Re: postgres and xquery

From

Rob Sargent

Date:

14 May 2013, 18:05:10

On 05/14/2013 08:48 AM, kristian kvilekval wrote:

I was really hoping to see be able to store several ten's of millions XML documents in postgres, but I would also like to use Xquery to retrieve results. Back in 2010 there was some mailing list discussion about using integrating the xquery processor of zorba into postgres. I was trying to gauge the interest level and if anybody had attempted it. As you say, JSON has stolen all the thunder, and in fact the Zorba people have worked on JSONiq (an xquery processor for JSON data structures), but our project uses XML. We like the flexibility you get with Xquery and I am looking around for some solutions.

On Tue, May 14, 2013 at 12:37 AM, John R Pierce <pierce@hogranch.com> wrote:
On 5/13/2013 9:31 PM, kristian kvilekval wrote:
I saw on the mailing list that back in 2010 there was some discussion of using Zorba to add xquery capabilities to postgres. I was wondering if any progress had been made on this and what the current interest levels of supporting xml in postgres are?

Zorba has a JDBC database interface, and JDBC can talk to postgres. this would let you use zorba to query a postgres database via xQuery. isn't that what you want?

--
john r pierce 37N 122W
somewhere on the middle of the left coast

--
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Have you try xpath in postgres yet? We store xml, but do very little xpathing against it. I do it mainly for trouble shooting. We have a problem with multiple namespaces used in our content. Because of that one is often left searching for '//*/name()="some-value"' to get around the namespace differences inter and intra record. But xpath and particularly xpath_table work quite well even with that constraint.

Re: postgres and xquery

From

Merlin Moncure

Date:

14 May 2013, 18:22:30

On Tue, May 14, 2013 at 9:48 AM, kristian kvilekval <kris@cs.ucsb.edu> wrote:
>
> I was really hoping to see be able to store several ten's of millions XML
> documents in postgres, but I would also like to use Xquery to retrieve
> results.  Back in 2010 there was some mailing list discussion about using
> integrating the xquery processor of zorba into postgres.  I was trying to
> gauge the interest level and if anybody had attempted it.  As you say, JSON
> has stolen all the thunder, and in fact the Zorba people have worked on
> JSONiq (an xquery processor for JSON data structures), but our project uses
> XML.    We like the flexibility you get with Xquery and I am looking around
> for some solutions.

Advise refining your requirements so that you can search your xml with
xpath and then do transformations in sql -- this is more powerful than
it looks on the surface.  If you must use xquery, the shortest path to
get there is possibly through a backend pl (say perl or python) so
that you can tap into fancy xml support there.  If not xpath, then
xslt -- xquey is just a mess IMNSHO and should be avoided, especially
for new programming efforts.

JSON is superior in just about every way -- less verbose, more regular
syntax, faster parsing.  JSON is also very tightly integrated to
postgres (especially with coming 9.3) so that serialization to/from
database data is automagical and essentially eliminates the need for
the querying/construction steps that make dealing with xml such a bear
(especially when serializing from database).  So much so that if I was
tasked with complex xml transformations in the database I'd maybe
consider converting them to json, doing the transformation, then back
to xml again.

merlin