Hey Mark, I have tested the options you gave me to run queries with python_map. For now, I have decided to create an empty table and fill it later, using the parallelized function. So I made a few tests and this approach should work. Here you can find the explain of the query (I have set just 3 threads for now) http://pastie.org/private/ar4kbpnn7qiadulxp5g http://pastie.org/private/ar4kbpnn7qiadulxp5g . The operator ‘batpyapimap.eval’ is called 3 times so everything should be alright. Except for the fact that the 3 python calls do not run in parallel but one after the other. I can see clearly from the logs I print that the python function fires up the first time with the first slice of input parameters, when it completes it fires up a second time and so on… Why is that? Currently I am not gaining anything because the zero actual parallelization.. Thank you, Stefano