Can you try enabling "use native query"? The driver will send the query to Impala verbatim (sometimes the driver may make some changes to the SQL).   http://www.cloudera.com/content/cloudera/en/documentation/connectors/latest/PDF/Cloudera-JDBC-Driver-for-Impala-Install-Guide.pdf   ... View more

Sorry for the wait. Here's what I think is happening.   Impala deals with inline views by substituting the select-list expressions from the inline view in the parent query block. What that means in your case, is that many of the expensive expressions inside your inline view are executed multiple times in the slow non-ORDER-BY version of your query.   For example, every reference to "setup_time" in the outer select list is replaced by the corresponding expression from the inline view, i.e. setup_time --> case when regexp_extract(...) then hours_add(...) else setup_time_ts end setup_time   As a result, not only are those expensive expressions only executed at the coordinator, but the expensive expressions are evaluated multiple times because they are referenced multiple times in the outer select list.   In the ORDER BY version of the query, this redundant expression evaluation is avoided because the ORDER BY materialized its input, so while the same inline view expression substitutions takes place, the outer references are substituted with materialized column references (i.e., the expensive expression is only evaluated once), i.e. setup_time --> materialized column produced by the ORDER BY   Hope this makes sense!   Alex   ... View more