I have a simple but big spatial table with approx 93 000 000 lines.
I use QGIS, the open-source GIS software to display this data. To fetch the polygons to draw on QGIS map, QGIS launch a first DECLARE CURSOR query, then fetch data 2000 by 2000.
I have seen that this DECLARE has bad perf compared to a simple SQL query :
Do you have any clue about this query plan ? Should I add some table specific weight, stats, etc. to help the DECLARE clause to use the indexes as done for the simple SELECT ?
