shapes to MySQL

[Brent Wood]

> To answer your question, NO, you can not put your shapefiles in MySQL 
> and render then via mapserver. You can put them in postGIS, but they 
> will be slower than shapefiles.


Umm... by my (totally subjective & unauthoritative) benchmarks, if you have a
spatial & aspatial query applied to a properly indexed dataset in PostGIS, it
can be faster than a shapefile. A shapefile was faster for plotting the entire
dataset, but, for example, a national elevation contour dataset (20m intervals)
is faster than the same data as shapefiles when zooming & the zoom layers have
different sets of contours (from all at 20m when zoomed in to 100, to 200, to
500m when zoomed right out).

I haven't tried as much with query layers, but when working with a dataset of
millions of records, the PostGIS data seems more responsive, quite
significantly in some cases.

Generally I find that the larger the dataset & the more complex the
query/filter you apply, the more PostGIS is likely to be faster. Conversely,
for smaller & simpler datasets/filters, shapefiles are indeed faster.

Given the nature of databases & their overhead this is about what I'd expect. 


So just to check that my impressions are not colored too much by my
expectations, do others agree with this or not?



   Brent Wood