[postgis-users] Loading Data / Refreshing every 5 minutes

[Ben Madin]

My very uneducated perspective would be that it depends on how much of the data (ie what sort of subset) the user is requesting. If they are just getting the whole table every time, there may be limited benefit to large amounts of indexing. If you are loading the radar shapefile for continental Australia, but your users are on the coast somewhere between Exmouth and Karratha, then I think an index is probably essential for any sort of performance.

As a vague point of interest, why are you converting the shapefile to postgis for 5 minutes, then deleting the whole lot - there might be very little speed benefit to doing this. Could you not just load the new data into the same table (ie append) with a  field (something like createdon timestamp not null default now() or similar) for the date and time. Then the user request could be modified to get the most recently loaded data... or loops of the last 20 minutes... or something like that.

Just a thought, it might save the blank pages.

cheers

Ben





On 03/05/2011, at 11:17 AM, Chris Brisendine wrote:

> Every once and a while when a wms user (on Geoserver) goes to refresh the view (Latest Radar Image) they get a blank page, just catching it when there is no data in the table.
> There is not any data verification on my end its just a simple conversion of a polygon to postgis for geoserver to use.  Do I need to worry about indexing and vacuuming since the data changes
> so much? I am very new to pgsql and still trying to learn everything...
> 
> 
> _______________________________________________
> postgis-users mailing list
> postgis-users at postgis.refractions.net
> http://postgis.refractions.net/mailman/listinfo/postgis-users