pgaref commented on a change in pull request #1147:
URL: https://github.com/apache/hive/pull/1147#discussion_r458205456
##########
File path: ql/src/java/org/apache/hadoop/hive/ql/ppd/SyntheticJoinPredicate.java
##########
@@ -339,6 +339,12 @@ String getFuncText(String funcText, final int srcPos) {
vector.add(right, left);
break;
case JoinDesc.LEFT_OUTER_JOIN:
+ case JoinDesc.ANTI_JOIN:
+ //TODO : In case of anti join, bloom filter can be created on left
side also ("IN (keylist right table)").
+ // But the filter should be "not-in" ("NOT IN (keylist right table)")
as we want to select the records from
+ // left side which are not present in the right side. But it may cause
wrong result as
+ // bloom filter may have false positive and thus simply adding not is
not correct,
+ // special handling is required for "NOT IN".
Review comment:
Makes sense, for this particular purpose in the future we could
something like ``The opossite bloom filter`` to support such cases
https://github.com/jmhodges/opposite_of_a_bloom_filter/
----------------------------------------------------------------
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:
[email protected]
---------------------------------------------------------------------
To unsubscribe, e-mail: [email protected]
For additional commands, e-mail: [email protected]
