[ https://issues.apache.org/jira/browse/DRILL-5737?page=com.atlassian.jira.plugin.system.issuetabpanels:all-tabpanel ]
Sorabh Hamirwasia reassigned DRILL-5737: ---------------------------------------- Assignee: Sorabh Hamirwasia > Hash Agg uses more than the allocated memory under certain low memory > conditions > -------------------------------------------------------------------------------- > > Key: DRILL-5737 > URL: https://issues.apache.org/jira/browse/DRILL-5737 > Project: Apache Drill > Issue Type: Bug > Reporter: Sorabh Hamirwasia > Assignee: Sorabh Hamirwasia > > Reported by [~rkins] > Based on the memory computations drill thinks that there is not sufficient > memory and falls back to a single partition case. The single partition case > however does not respect the memory constraints imposed and completes the > query using ~130MB of memory > {code:java} > alter session set `planner.width.max_per_node` = 1; > alter session set `planner.memory.max_query_memory_per_node` = 117127360; > select count(*) from (select max(nulls_col), max(length(nulls_col)), > max(`filename`) from dfs.`/drill/testdata/hash-agg/data1` group by > no_nulls_col) d; > {code} > Based on analysis by [~ben-zvi] this is by design. When the Hash Aggr Op > finds that there is not enough memory for at least two partitions, it falls > back to the pre 1.11 behavior ( using 10GB limit ). > Solution is to provide a configuration based on which the fallback will be > either allowed or query will be failed. -- This message was sent by Atlassian JIRA (v6.4.14#64029)