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https://issues.apache.org/jira/browse/IMPALA-3652?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=16568501#comment-16568501
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Tim Armstrong commented on IMPALA-3652:
---------------------------------------
The above query seems to work now but I can cause problems with this query:
{noformat}
select c_custkey, c_mktsegment, o_orderkey, o_orderdate
from customer c,
(select distinct 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;
{noformat}
> 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: Tim Armstrong
> 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}
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