[postgis-devel] Re: [postgis-users] Change default "canonicalform"of spatial objects

[Mark Cave-Ayland]

Hi strk,

> -----Original Message-----
> From: postgis-devel-bounces at postgis.refractions.net 
> [mailto:postgis-devel-bounces at postgis.refractions.net] On 
> Behalf Of strk at refractions.net
> Sent: 23 March 2005 10:13
> To: 'PostGIS Development Discussion'
> Subject: Re: [postgis-devel] Re: [postgis-users] Change 
> default "canonicalform"of spatial objects

(cut)

> Mark, your usage of view is probably enough for the average 
> user, anyway (just for the sake of discussion), my 
> postgis_set() function would set in-transaction variable. The 
> canonical_ascii_output would by default be HEXWKB, so dumps 
> (which starts in a new transaction) will always be HEXWKB and 
> input would not be influenced. In-transaction settings might 
> be also useful for other psql-based users. Think of something like:
> 
> 	postgis_set("precision", "15.15");
> 	postgis_set("precision", "6");
> 	postgis_set("bbox_cache_strategy", "auto");
> 	postgis_set("bbox_cache_strategy", "when_simple");
> 	...
> 
> ... Yes, would make things more complex, but do you see an 
> use for it ?

Hmmm it could be something that we could consider... My immediate concern
would be the penalty of looking up each of the variables during runtime, and
how you could enforce transactional separation without the cost of storing
the data in tuples (it may be quite easy to do it once per backend by
storing the variables in memory but we'd have to make sure it didn't upset
people using connection pooling).

IMHO it's something that would require quite a bit of testing, and so would
be better to revisit this after 1.0.0 final release, especially as I think
RC4 is definitely the closest yet... ;)


Kind regards,

Mark.

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