[postgis-devel] Transform fails in new transform caching code

strk at refractions.net strk at refractions.net
Fri Nov 25 14:19:21 PST 2005

On Sat, Nov 26, 2005 at 10:34:31AM +1300, Jeremy Palmer wrote:
> As a side question, I noticed when looking through the lwgeom_transform.c
> source that the proj cache size is hard set to 8. Is there a reason for
> this? Why not just have a cache as large as require for the transaction? I
> suppose for my query I can just sort by srid to minimise the number of db
> lookups, but this will not always be appropriate.

The cache stores projection objects. You'll likely use only two entry
for your whole portal (source and target SRIDS).
If you have mixed srid geometries in your table, well you'll likely
need more... if one of the SRIDS is constant (target, likely) sorting
input by SRID should help.


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