so 26. 8. 2023 v 22:47 odesÃlatel Chapman Flack <c...@anastigmatix.net> napsal:
> On 2023-08-26 16:00, Pavel Stehule wrote: > > Saxon can be an interesting library, but nobody knows if integration > > with > > Postgres is possible. Their C implementation is Java compiled/executed > > by GraalV. > > Indeed, such an integration would probably not be in core. > > Of the two possible-ways-forward described on that wiki page, the one > that didn't rely on the defunct XQC was one involving query rewriting. > Have the parser understand the SQL/XML customized syntax, and define > a set of ordinary functions it will be rewritten into. (This idea is > bolstered somewhat by the fact that many things in SQL/XML, XMLTABLE > for example, are /defined in the standard/ in terms of query rewriting > into calls on simpler functions.) > > Then let there be an extension, or ideally someday a choice of > extensions, supplying those functions. > > As to whether running Saxon in a Postgres extension is possible, that's > been an example that ships with PL/Java since 1.5.1 five years ago. > The most simple "solution" can be the introduction of some new hooks there. Then you can write an extension that will call PL/Java functions > > It's too bad the other projects have stalled; it's good to have more > than one ready option. But Saxon shows no sign of going away. > > Perhaps the act of devising a standardized rewriting of queries > onto a standardized set of loadable functions could be of interest > to other DBMS projects as well. It's hard to imagine another DBMS > not being in the same boat (if it isn't from a rich commercial firm > that happens to have a modern XQuery implementation in-house). > > Maybe having that set of functions specified, with the prospect > that more than one DBMS might be interested in a project > implementing them, even inspires someone to go look at the > xqilla or zorba repos to see how far they got, and pick up > the baton, and then there could be more than one option. > Another possibility is revitalization of libxml2. There was an extension http://www.explain.com.au/libx/ But the code is not available to download too, but extending libxml2 is feasible. I am not sure how valuable this work can be. Probably whoever really needs it uses some Java based solution already. Regards Pavel > Regards, > -Chap >
