Doing an ST_Intersection is much slower than relation checks such as
, ST_CoveredBy, and , ST_Within .
In many situations you know the intersection of 2 geometries
without actually computing an intersection. In these cases, you can skip the costly ST_Intersection call. Cases like this:
ST_SetSRID doesn't change the coordinates but adds meta data to state what spatial reference system the coordinate actually are.
If you stamped your WGS 84 long lat data as a meter based projection. Guess what? Its still long lat.
A spade …
If you have a problem that involves finding the things within X distance of other things or finding what things
have nothing within X distance
do not use ST_Distance for filtering and also do not try to use ST_Intersects + ST_Buffer.
Use ST_DWithin instead. Why?
ST_DWithin can use an index and ST_Distance can not …