[ https://issues.apache.org/jira/browse/IMPALA-3652?page=com.atlassian.jira.plugin.system.issuetabpanels:all-tabpanel ]
Work on IMPALA-3652 started by Thomas Tauber-Marshall. ------------------------------------------------------ > Fix resource transfer in subplans with limits > --------------------------------------------- > > Key: IMPALA-3652 > URL: https://issues.apache.org/jira/browse/IMPALA-3652 > Project: IMPALA > Issue Type: Task > Components: Backend > Affects Versions: Impala 2.6.0 > Reporter: Tim Armstrong > Assignee: Thomas Tauber-Marshall > Priority: Major > Labels: resource-management > > There is a tricky corner case in our resource transfer model with subplans > and limits. The problem is that the limit in the subplan may mean that the > exec node is reset before it has returned its full output. The resource > transfer logic generally attaches resources to batches at specific points in > the output, e.g. end of partition, end of block, so it's possible that > batches returned before the Reset() may reference resources that have not yet > been transferred. It's unclear if we test this scenario consistently or if > it's always handled correctly. > One example is this query, reported in IMPALA-5456: > {code} > select c_custkey, c_mktsegment, o_orderkey, o_orderdate > from customer c, > (select o1.o_orderkey, o2.o_orderdate > from c.c_orders o1, c.c_orders o2 > where o1.o_orderkey = o2.o_orderkey limit 10) v limit 500; > {code} -- This message was sent by Atlassian JIRA (v7.6.3#76005) --------------------------------------------------------------------- To unsubscribe, e-mail: issues-all-unsubscr...@impala.apache.org For additional commands, e-mail: issues-all-h...@impala.apache.org