Re: patch: function xmltable

On Fri, Nov 25, 2016 at 3:31 AM, Pavel Stehule <pavel.stehule@gmail.com> wrote:
> 2016-11-24 18:51 GMT+01:00 Tom Lane <tgl@sss.pgh.pa.us>:
>> 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?
>
> I am sorry - I don't see it. There is nothing complex manipulation with
> XPath expressions.

You are missing the point here, which is to make the implementation
footprint as light as possible, especially if the added functionality
is already present in a dependency that Postgres can be linked to. OK,
libxslt can only be linked with contrib/xml2/ now, but it would be at
least worth looking at how much the current patch can be simplified
for things like transformTableExpr or XmlTableGetValue by relying on
some existing routines. Nit: I did not look at the patch in details,
but I find the size of the latest version sent, 167kB, scary as it
complicates review and increases the likeliness of bugs.
-- 
Michael