[Gvsig_english] (no subject)

[Holger Jaekel]

Dear gvSIG developers,

when we add a layer from PostGIS to gvSIG 1.9, we can see that two ressource intensive operations are performed on the database:

1. A database cursor is created for this layer in PostGisDriver.setData(IConnection, DBLayerDefinition), which selects all objects from the table
2. A Hashtable is filled in PostGisDriver.doRelateID_FID(), which contains one entry for each object from our layer.

We have to work with layers that contain more than 10,000,000 polygons. In that case, the cursor allocates many ressources on the database side, so this solution does not scale very well for many users. In the second step, gvSIG tries to create a Hashtable with >10,000,000 entries, which will create an OutOfMemoryException. This will also happen if we use "maxScale" for this layer.

Any hints how gvSIG can handle large layers?

Thank you very much for your help,
  Holger

-- 
Holger Jaekel
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