maheshk114 commented on a change in pull request #1147:
URL: https://github.com/apache/hive/pull/1147#discussion_r460001925
##########
File path:
ql/src/java/org/apache/hadoop/hive/ql/optimizer/stats/annotation/StatsRulesProcFactory.java
##########
@@ -2606,6 +2607,17 @@ private long computeFinalRowCount(List<Long>
rowCountParents, long interimRowCou
// max # of rows = rows from left side
result = Math.min(rowCountParents.get(joinCond.getLeft()), result);
break;
+ case JoinDesc.ANTI_JOIN:
+ long leftRowCount = rowCountParents.get(joinCond.getLeft());
+ if (leftRowCount < result) {
+ // Ideally the inner join count should be less than the left row
count. but if its not calculated
+ // properly then we can assume whole of left table will be
selected.
+ result = leftRowCount;
Review comment:
This case will come if the stats are not proper. So to be on safer side,
i assume that all rows from the left side will be projected. That is the max
value. If set it to 0, it should not trigger some re-write, assuming the join
result is empty.
----------------------------------------------------------------
This is an automated message from the Apache Git Service.
To respond to the message, please log on to GitHub and use the
URL above to go to the specific comment.
For queries about this service, please contact Infrastructure at:
us...@infra.apache.org
---------------------------------------------------------------------
To unsubscribe, e-mail: gitbox-unsubscr...@hive.apache.org
For additional commands, e-mail: gitbox-h...@hive.apache.org
