[
https://issues.apache.org/jira/browse/DRILL-6307?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=16453409#comment-16453409
]
ASF GitHub Bot commented on DRILL-6307:
---------------------------------------
Github user ppadma commented on a diff in the pull request:
https://github.com/apache/drill/pull/1228#discussion_r184258865
--- Diff:
exec/java-exec/src/main/java/org/apache/drill/exec/record/RecordBatchSizer.java
---
@@ -536,6 +556,11 @@ public ColumnSize getColumn(String name) {
*/
private int netRowWidth;
private int netRowWidthCap50;
+
+ /**
+ * actual row size if input is not empty. Otherwise, standard size.
+ */
+ private int rowAllocSize;
--- End diff --
actually, this is a problem only for lateral join. In lateral join, right
side will work on one row at a time from left side. If right side produces zero
rows because of empty array or some other reason, for left outer join, we still
have to finish cross join for that row from left side by having nulls for right
side columns. Then, we go to next row on left side, continuing to work on
filling the output batch till it is full. What that means is we have to
allocate vectors based on that first batch on right side, which can be empty.
> Handle empty batches in record batch sizer correctly
> ----------------------------------------------------
>
> Key: DRILL-6307
> URL: https://issues.apache.org/jira/browse/DRILL-6307
> Project: Apache Drill
> Issue Type: Bug
> Components: Execution - Flow
> Affects Versions: 1.13.0
> Reporter: Padma Penumarthy
> Assignee: Padma Penumarthy
> Priority: Major
> Fix For: 1.14.0
>
>
> when we get empty batch, record batch sizer calculates row width as zero. In
> that case, we do not do accounting and memory allocation correctly for
> outgoing batches.
> For example, in merge join, for outer left join, if right side batch is
> empty, we still have to include the right side columns as null in outgoing
> batch.
> Say first batch is empty. Then, for outgoing, we allocate empty vectors with
> zero capacity. When we read the next batch with data, we will end up going
> through realloc loop. If we use right side row width as 0 in outgoing row
> width calculation, number of rows we will calculate will be higher and later
> when we get a non empty batch, we might exceed the memory limits.
> One possible workaround/solution : Allocate memory based on std size for
> empty input batch. Use allocation width as width of the batch in number of
> rows calculation.
--
This message was sent by Atlassian JIRA
(v7.6.3#76005)
