If you have more than a handful of users it becomes difficult to manage the large number of pools. Resource limits are also of limited use - you can limit the total consumption per user, but you can't guarantee that any group of users gets memory. ... View more

Yeah we need to make some changes in Impala to optimise this case (large SELECT result sets) better. We have some of that work in Impala.   If you're doing large extracts of data, it's often better to do a "CREATE TABLE AS SELECT" into a text table and download those files directly from the filesystem, if that's possible. ... View more

Impala is not designed for traditional OLTP and doesn't have transaction support that would line up with what TPC-C expects. ... View more

If you want to do the implicit join between the table and the nested collection, you need to reference the nested collection using the alias that you used for the table. Otherwise the top-level table and the nested collection are treated as independent table references and the query means "return the cartesian product of the tables".   I.e. you want to rewrite as follows:   select rta.transaction_purchase_id, rta.cigarette_transaction_flag, rta.non_cig_merch_transaction_flag, bow.item from wdl_atomic.retail_transaction_attribute rta, rta.retail_offering_material_group_distinct_list bow where rta.fiscal_period_id = 2019001; That will solve your issue. ... View more