[
https://issues.apache.org/jira/browse/DRILL-5774?page=com.atlassian.jira.plugin.system.issuetabpanels:all-tabpanel
]
Arina Ielchiieva updated DRILL-5774:
------------------------------------
Fix Version/s: (was: 1.12.0)
1.13.0
> Excessive memory allocation
> ---------------------------
>
> Key: DRILL-5774
> URL: https://issues.apache.org/jira/browse/DRILL-5774
> Project: Apache Drill
> Issue Type: Bug
> Components: Execution - Relational Operators
> Affects Versions: 1.11.0
> Reporter: Robert Hou
> Assignee: Paul Rogers
> Fix For: 1.13.0
>
>
> This query exhibits excessive memory allocation:
> {noformat}
> ALTER SESSION SET `exec.sort.disable_managed` = false;
> alter session set `planner.width.max_per_node` = 1;
> alter session set `planner.disable_exchanges` = true;
> alter session set `planner.width.max_per_query` = 1;
> select count(*) from (select * from (select id, flatten(str_list) str from
> dfs.`/drill/testdata/resource-manager/flatten-large-small.json`) d order by
> d.str) d1 where d1.id=0;
> {noformat}
> This query does a flatten on a large table. The result is 160M records.
> Half the records have a one-byte string, and half have a 253-byte string.
> And then there are 40K records with 223 byte strings.
> {noformat}
> select length(str), count(*) from (select id, flatten(str_list) str from
> dfs.`/drill/testdata/resource-manager/flatten-large-small.json`) group by
> length(str);
> +---------+-----------+
> | EXPR$0 | EXPR$1 |
> +---------+-----------+
> | 223 | 40000 |
> | 1 | 80042001 |
> | 253 | 80000000 |
> {noformat}
> From the drillbit.log:
> {noformat}
> 2017-09-02 11:43:44,598 [26550427-6adf-a52e-2ea8-dc52d8d8433f:frag:0:0] DEBUG
> o.a.d.e.p.i.x.m.ExternalSortBatch - Actual batch schema & sizes {
> str(type: REQUIRED VARCHAR, count: 4096, std size: 54, actual size: 134,
> data size: 548360)
> id(type: OPTIONAL BIGINT, count: 4096, std size: 8, actual size: 9, data
> size: 36864)
> Records: 4096, Total size: 1073819648, Data size: 585224, Gross row width:
> 262163, Net row width: 143, Density: 1}
> {noformat}
> The data size is 585K, but the batch size is 1 GB. The density is 1%.
--
This message was sent by Atlassian JIRA
(v6.4.14#64029)
