Hello everybody, I have 2 tables:
T1: 8 columns. 1 geometry column of type polygon. UTM coords. Thousands of rows T2: 4 columns. 1 geometry column of type multipolygon. UTM coords. 29 rows. Each multipolygon has thousands of polygons. I need to add a new column to T1. The new column's value will be taken from one of the T2's fields (the 4th one). For each row of T1, I have to find the multipolygon of T2 that contains the polygon of T1. When matchs, I have to update the new T1's column with the value of 4th column of the T2 matching row. I'm trying something like this: UPDATE T1 SET new_column = (SELECT T2.fourth_column from T1 JOIN T2 ON ST_DWithin(T1.polygon, T2.multipolygon, 0.0)) Yes, I know that I can use ST_Within(T1.polygon, T2.multipolygon)), but I would need PostGIS with GEO support, and I can't compile it again. Anyway, my big problem is that the query takes really LONG time. More than 1 hour. And I have to translate this test to a bigger enviroment (bigger tables). I' ve created index on the geometry columns in both tables, but doesn't seem to be enough... Any clues? Thanks in advance Jorge
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