We have a strange issue going on in our 5 node cluser (256 gb RAM, with 130 gb assigned to Imapala in each node). We have been unable to run a particular query that is joining quite a few tables. It also creates 5 temporary tables that is ultimately joins to create a final query output that is supposed to be passed back to Informatica BDM.   But as soon as the query is sent from Informatica, it finishes running and returns no output. This behaviour is not observed in our pre-prod environment, but that again does not have that much data. What our Cloudera admin can see is that the query is coming from Informatica, but he sees a LIMIT 0 added to the end, which we do not have in Informatica mapping. That then likely causes no output to be returned.  He sees similar thing for a different query from a different mapping, but in that case, as second query is seen without LIMIT 0 and we do get data returned for that Informatica mapping.   So we are are just wondering if we have a cluster configuration issue or does Impala issue a limit 0 query first to get the EXPLAIN plan and then issues the real query, but in this case, it is failing to do so for some reason.   When I ran the EXPLAIN command around the complex query from our query tool (TOAD Data point connected via Impala ODBC Driver), I get this   Per-Host Resource Reservation: Memory=3.85GB Per-Host Resource Estimates: Memory=9.83GB   I do not have expertise to understand rest of the 1000 line EXPLAIN commands output to understand what is the total Impala RAM that this query is demanding.   Any pointers from the community experts is much appreciated ... View more