Function session_sql_gen 

pub fn session_sql_gen<R: Rng>(rng: &mut R) -> String

TODO(noel): Eventually all session variables should be fuzzed. For now we start of with a few hardcoded configs. Some config need workarounds, for instance QUERY_MODE, which can lead to stack overflow (a simple workaround is limit length of generated query when QUERY_MODE=local.