[
Date Prev][
Date Next][
Thread Prev][
Thread Next][
Date Index][
Thread Index]
[
List Home]
|
Re: [udig-devel] Re: CRS - "Bursa wolf parameters required."
|
Martin Desruisseaux wrote:
Jody Garnett a écrit :
The EPSG has implemented the code into a SQL for MySQL. With some
modifications to the SQL, could it not be implemented into PostGIS and
become part of the data model. Hence the codes could be looked up in
the
DB, rather than maintaining an external file.
Now there has been some progress recently, they have renamed the epsg
plugin in preparation for actually starting this work. Bascially
Martin found a vounteer to help with the HSQL side of things.
Yes. Richard Didier prepared a HSQL database will all EPSG data,
bundled in a JAR file. But there is some aspects of HSQL that make me
uncomfortable: all data are specified as SQL scripts bundled in the
JAR, with thousands on "INSERT INTO ... VALUES ..." statements, which
seems really inefficient to me. But it seems to be the way HSQL work.
It is also my understanding that all data are loaded in memory, which
is again inefficient (why keep 3000+ CRS in memory when we usually
uses only a few of them)? So we have a choice:
1) Either we provide the HSQL plugin anyway as is, with the above-cited
overhead.
2) Either we search for an other database engine (any idea?)
Direct GeoTools access to the EPSG database is a "great idea" that none
has actually implemented.
It is already implemented and working, since February. It work with
MS-Access database, and should work with PostgreSQL too.
Look at plugin/epsg-access for an example connecting to the MS-Access
database. This plugin also provides instructions about how to connect
to a PostgreSQL database.
Martin.
_______________________________________________
User-friendly Desktop Internet GIS (uDig)
http://udig.refractions.net
http://lists.refractions.net/mailman/listinfo/udig-devel
We used initially Mckoi then the Derby Eclipse plugin for this purpose,
plus other requirements HSQL though useful is rather simplistic (one of
its features) Database facilities have a habit of growing.
Tony Kennedy
