kgyrtkirk commented on a change in pull request #1250:
URL: https://github.com/apache/hive/pull/1250#discussion_r457944846
##########
File path:
ql/src/java/org/apache/hadoop/hive/ql/exec/vector/VectorGroupByOperator.java
##########
@@ -561,17 +590,25 @@ private void flush(boolean all) throws HiveException {
maxHashTblMemory/1024/1024,
gcCanary.get() == null ? "dead" : "alive"));
}
+ int avgAccess = computeAvgAccess();
/* Iterate the global (keywrapper,aggregationbuffers) map and emit
a row for each key */
Iterator<Map.Entry<KeyWrapper, VectorAggregationBufferRow>> iter =
mapKeysAggregationBuffers.entrySet().iterator();
while(iter.hasNext()) {
Map.Entry<KeyWrapper, VectorAggregationBufferRow> pair = iter.next();
+ if (!all && avgAccess >= 1) {
+ // Retain entries when access pattern is > than average access
+ if (pair.getValue().getAccessCount() > avgAccess) {
Review comment:
the new patch flattens an LRU logic into the operator itself - I rather
liked the earlier pluggable approach better; since that could enable us to
later plug-in LFRU which might be the best for this job...
I believe that is because we might not want to plug in different kind of
algos here...which is fine
however I think we can shift toward an LFRU alike operation by penalitizing
entries which are kept:
* reset accesscount of kept entries to 0
* or...by multiply it by .5 or something...(can be placed in conf)
----------------------------------------------------------------
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]
