docker
First run TPC-H dbgen and copy the tpch *.tbl files to ./shared. If you don't have TPC-H dbgen, then use this https://github.com/gregrahn/tpch-kit/tree/master/dbgen.
Then,
make
make explain-q15
The way we use docker postgres is one instance of 'postgres' image for the server and one instance of 'postgres' image each time we make a client request.