WFS performance issue

[Yewondwossen Assefa]

Frank Warmerdam wrote:
> On Tue, 22 Mar 2005 10:19:01 -0500, Yewondwossen Assefa
> <assefa at dmsolutions.ca> wrote:
>
>>Frank,
>>
>>   The WFS code to modify should not be that bad since the functions to
>>transalte from filter encoding xml syntax to mapserver expression are
>>localized in separate functions and I could twick the code to generate
>>sql statements instead of Mapserver expressions and set the layers'
>>FILTER.
>>  The problem I have is how would I test this ? I do not have Orcacle
>>setup here ? What would be my best option to do testing on this ? Could
>>I use OGR layers with underlaying layers other than oracle ?
>
>
> Assefa,
>
> My suggestion would be that you translate to SQL suitable for use
> with PostGIS and test that.  Once that is working smoothly, you
> could invoke the same code for Oracle and leave it up to Arnulf
> to test it.   Hopefully pure attribute WHERE clauses would be pretty
> similar between Oracle and Postgres.
>
> In fact, as you suggest you could also just drive this against OGR
> as it understands WHERE style FILTER clauses as long as the
> filter string is prepended with "WHERE".  It won't generally give
> much performance benefit unless the backend is a database.  But
> you could setup tests against a given shapefile using direct
> mapserver shapefile access (traditional) and then routing the same
> requests for OGR with WHERE clauses to verify that both forms are
> giving the same results.
>
> One nice thing about OGR based tests is that it would be easy
> to add to a test suite.  Also, OGR SQL is so basic that if an SQL
> where clause works against OGR SQL it will likely work fine in
> Oracle or Postgres.
>
> I think this would be really exciting progress to make, and I will
> help out in any way I can.
>

Frank,

  I will give it a try late this week with OGR driver. Should be easy
enough to test that case. I have entered a bug 1292 to do the following
on this.

Thanks.



--
----------------------------------------------------------------
Assefa Yewondwossen
Software Analyst

Email: assefa at dmsolutions.ca
http://www.dmsolutions.ca/

Phone: (613) 565-5056 (ext 14)
Fax:   (613) 565-0925
----------------------------------------------------------------