[Mapserver-users] Fastest Data Format

[Paul Ramsey]

ArcIMS seems to handle SDE just fine, but that should be no surprise :) 
I imagine that ArcIMS uses connection pooling to avoid the overhead 
associated with making SDE connections.

I should reiterate at this point that the performance problem does not 
adhere to SDE necessarily or to Mapserver necessarily, but to the amount 
of time it takes to negotiate a connection with an SDE server. Once the 
connection is made, everything is performant. It is making the 
connection which is the issue. If you are only making one connection, 
probably it is completely reasonable.

However, the current design of Mapserver treats each layer as a distinct 
entity, and each layer datasource as a distinct entity. So for each 
SDE-based layer, there is a separate SDE connection to be made. Over 
numerous layers, things can add up to quite a long delay.

Jan Hartmann has made a proposal for connection pooling between layers, 
I do not know if he has a preliminary implementation or if such an 
implementation will be included in 3.7.

Paul

Martin, Daniel wrote:
> I'm curious, does another GIS product access SDE faster than MapServer?
> 
> The reason I ask is that I also experience slower performance using MapInfo
> data via OGR.  Certainly I realize MapInfo data isn't nearly as robust as
> SDE.  However, MapServer serves the same map quicker than MapInfo's own GUI
> application.  I can't ask for much more than that.
> 
> -Dan