[Mapserver-dev] Any experience with SQL Relay?

[David Blasby]

Sean Gillies wrote:
> Thanks, Dave.  I think that we'd have to write new connector code that 
> would
> be inspired by that in mappostgis.c, but using the sqlrelay API.  I'm still
> undecided about starting in on this.

If you're going to do that, I suggest you make a "mapdatabase.c" file 
that would serve Oracle, PostGIS, SQLrelay, MySQL, and SDE layers. 
Having everything unified in one file would be a big help - only one 
place to test and find bugs...

"mappostgis.c" should be re-written instead of modified.

** Ideally I'd like to see the way the current query mechanism works be 
improved.  It might be worth experimenting with a "query cache" - it 
would significantly improve performance for all the DB layers, at the 
cost of cache memory.

** I'd also like to see the postgis layer *not* read all the results 
into memory.  This can be done with "FETCH N" instead of the current 
"FETCH ALL" commands on the cursor.  Ideally, you could thread the query 
- improving performance and significantly cutting down on memory usage. 
  The threading portion is optional, but the "FETCH N" rows command is 
relatively simple...

dave