[postgis-devel] RE: pgxs

[Mark Cave-Ayland]

Hi strk,

> -----Original Message-----
> From: strk at refractions.net [mailto:strk at refractions.net] 
> Sent: 26 April 2005 14:01
> To: Mark Cave-Ayland (External)
> Cc: 'Jean David TECHER'; 'PostGIS Development Discussion'
> Subject: pgxs

(cut)

> You ironically asked me "Do you work for Microsoft" ?
> I can bounce that question back to you ;)

Lol :)

> Making PostgreSQL upgrade a prerequisite for PostGIS upgrade 
> sounds a bit unfriendly... would disturb me in a production 
> environment.
> 
> In the long run we can leverage this behaviour, but I think
> it is too early now. Pgsql 8.0 would be required and I'm not 
> sure about pgxs status in terms of "features". Have you 
> looked into it ? Does it give you enough abstraction to 
> really easy multiplaform builds ?
> 
> What we can consider in our efforts is "miming" the behaviour 
> of pgxs in terms of installation layout, to be compatible 
> when time come for a switch.

I think I may have confused people here by the wording of my email; I was
not suggesting that we force people to upgrade to PG 8.0 in order to run
PostGIS. What I am trying it point out is that at the moment, everyone who
has installed PostGIS must have a fully configured PG source tree available.
So an upgrade compile would be as simple as downloading the new source in
contrib/ then doing a make install.

I agree that building PostGIS without the source is something we should
definitely look at; however my concern is that I generally see quite a few
tweaks to the linker flags going through the PG lists to tweak
idiosynchrocies with particular platforms, and so I can see PostGIS always
having to play catch-up everytime changes are made to the Makefile.

So in brief, what I was suggesting was:

	1) Keep the existing --with-pgsql-src=/ptr/to/pgsql configure option
for PG < 8.0.
	This would still require a configure'd source tree as we do at the
moment,
	however everyone who uses PostGIS already has one ready and so I
can't see this
	being too much of a problem.

	2) Add another --with-pgxs=/ptr/to/pg_config configure option for PG
>= 8.0 which
	would allow PostGIS to build without a configure'd source tree.
These two options
	are mutually exclusive.

The compromise here was to not support building PostGIS *without* a
configure'd source tree for PG versions < 8.0 in order to prevent us from
having to maintain our own modified copies of Makefiles within the project
(in particular to gain access to linker and compiler flags). The pgxs
Makefile is an actual fact a modified version of the contrib/ Makefile and
so building PostGIS shouldn't be a problem :)


Kind regards,

Mark.

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