okumin commented on code in PR #5452:
URL: https://github.com/apache/hive/pull/5452#discussion_r1814927537


##########
ql/src/java/org/apache/hadoop/hive/ql/plan/mapper/PlanMapper.java:
##########
@@ -217,7 +230,11 @@ private void link(Object o1, Object o2, boolean mayMerge) {
     }
     if (mGroups.size() > 1) {
       if (!mayMerge) {
-        throw new RuntimeException("equivalence mapping violation");
+        LOG.warn("Illegally linking {} and {}", o1, o2);
+        if (failsWithIllegalLink) {
+          throw new RuntimeException("equivalence mapping violation");
+        }
+        isBroken.set(true);

Review Comment:
   Now, I understand what you said, maybe. I was convinced that it was all or 
nothing, which means I thought a partially valid PlanMapper could never exist. 
Your comment should be worth considering.
   
   I'm checking the source code with my mind updated.
   
   ```
   if (mGroups.size() > 1) {
     if (!mayMerge) {
       LOG.warn("Illegally linking {} and {}", o1, o2);
       return;
     }
   ```
   
   I guess we should be a bit more defensive. That's because we have two places 
using 
[AuxOpTreeSignature](https://github.com/apache/hive/blob/454415b4798dbb7accf5e5de23db3dc4801b7d68/ql/src/java/org/apache/hadoop/hive/ql/plan/mapper/AuxOpTreeSignature.java#L76)
 which [links all Operators with 
mayMerge=true](https://github.com/apache/hive/blob/454415b4798dbb7accf5e5de23db3dc4801b7d68/ql/src/java/org/apache/hadoop/hive/ql/plan/mapper/PlanMapper.java#L198-L219).
 It is not evident that it is safe(if it is safe, maybe we didn't need a 
validation here basically).
   
   ```
   if (mGroups.size() > 1) {
     if (!mayMerge) {
       LOG.warn("Illegally linking {} and {}", o1, o2);
       mGroups.forEach(g -> g.add(new 
OperatorStats.IncorrectRuntimeStatsMarker()));
       return;
     }
   ```
   
   I guess this can keep the valid part alive, marking the unexpected part 
invalidated and removing `PlanMapper#isBroken`. I am thinking of that approach.



-- 
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.

To unsubscribe, e-mail: gitbox-unsubscr...@hive.apache.org

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

Reply via email to