Horton

Re: PostgreSQL vs SQL/XML Standards

Chapman Flack <chap@anastigmatix.net>

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From: Chapman Flack <chap@anastigmatix.net>
To: Pavel Stehule <pavel.stehule@gmail.com>
Cc: PostgreSQL Hackers <pgsql-hackers@lists.postgresql.org>
Date: 2019-01-25T04:46:29Z
Lists: pgsql-hackers

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Hi,

On 01/21/19 01:33, Pavel Stehule wrote:
> ne 20. 1. 2019 23:13 odesílatel Chapman Flack <chap@anastigmatix.net>
> napsal:

>> form (whether or not the word LATERAL is used), and re-executes xmltable
>> whenever the referenced column value changes. In that case, whether the
>> default argument is evaluated at function entry or later doesn't seem
>> to matter: the function is re-executed, so evaluating the new default
>> at the time of entry is sufficient.
> 
> it has sense only for volatile functions. it was not often. On second hand
> deferred evaluation shoul not be a problem, and more, it is evaluated only
> when it is necessary, what is more sensible for me.

That makes sense. I trimmed the language about input rows and referring to
earlier columns, and put more emphasis on the usefulness of evaluating
volatile functions only when needed.

I am:

- re-attaching xmltable-xpath-result-processing-bugfix-5.patch unchanged
  (just so CF app does not lose track)

- re-attaching xmltable-xmlexists-passing-mechanisms-1.patch unchanged

- attaching for the first time xml-functions-type-docfix-1.patch

The doc patch is made to go on top of the passing-mechanisms patch
(there were some doc changes in passing-mechanisms, changed again in
the new patch to be links to the added Limits and Compatibility section).

I hope the patched docs describe accurately what we have at this point.

Regards,
-Chap

Commits

  1. Improve documentation about our XML functionality

  2. Improve documentation about our XML functionality.

  3. Add volatile qualifier missed in commit 2e616dee9.

  4. Fix crash with old libxml2

  5. Fix minor deficiencies in XMLTABLE, xpath(), xmlexists()

  6. Fix the BY {REF,VALUE} clause of XMLEXISTS/XMLTABLE

  7. doc: Update README.links

  8. XPath fixes: