Re: patch: function xmltable

Tom Lane <tgl@sss.pgh.pa.us>

From: Tom Lane <tgl@sss.pgh.pa.us>
To: Alvaro Herrera <alvherre@2ndquadrant.com>
Cc: Pavel Stehule <pavel.stehule@gmail.com>, Craig Ringer <craig@2ndquadrant.com>, PostgreSQL Hackers <pgsql-hackers@postgresql.org>
Date: 2016-11-24T17:51:52Z
Lists: pgsql-hackers
Alvaro Herrera <alvherre@2ndquadrant.com> writes:
> Pavel Stehule wrote:
>> 2016-11-24 0:13 GMT+01:00 Alvaro Herrera <alvherre@2ndquadrant.com>:
>>> Oh my, I just noticed we have a new xpath preprocessor in this patch
>>> too.  Where did this code come from -- did you write it all from
>>> scratch?

>> I wrote it from scratch - libxml2 has not any API for iteration over XPath
>> expression (different than iteration over XPath expression result), and
>> what I have info, there will not be any new API in libxml2.

> Okay, I agree that the default namespace stuff looks worthwhile in the
> long run.  But I don't have enough time to review the xpath parser stuff
> in the current commitfest, and I think it needs at the very least a lot
> of additional code commentary.

contrib/xml2 has always relied on libxslt for xpath functionality.
Can we do that here instead of writing, debugging, and documenting
a pile of new code?

			regards, tom lane


Commits

  1. Support XMLTABLE query expression

  2. Create <sect3> in the functions-xml section

  3. Improve handling of "UPDATE ... SET (column_list) = row_constructor".

  4. Add xmlexists function