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https://issues.apache.org/jira/browse/HIVE-24221?focusedWorklogId=500618&page=com.atlassian.jira.plugin.system.issuetabpanels:worklog-tabpanel#worklog-500618
]
ASF GitHub Bot logged work on HIVE-24221:
-----------------------------------------
Author: ASF GitHub Bot
Created on: 14/Oct/20 12:33
Start Date: 14/Oct/20 12:33
Worklog Time Spent: 10m
Work Description: zabetak commented on a change in pull request #1544:
URL: https://github.com/apache/hive/pull/1544#discussion_r504638460
##########
File path: ql/src/java/org/apache/hadoop/hive/ql/plan/ExprNodeDescUtils.java
##########
@@ -233,6 +235,23 @@ public static ExprNodeGenericFuncDesc
and(List<ExprNodeDesc> exps) {
return new ExprNodeGenericFuncDesc(TypeInfoFactory.booleanTypeInfo, new
GenericUDFOPAnd(), "and", flatExps);
}
+ /**
+ * Create an expression for computing a hash by recursively hashing given
expressions by two:
+ * <pre>
+ * Input: HASH(A, B, C, D)
+ * Output: HASH(HASH(HASH(A,B),C),D)
+ * </pre>
+ */
+ public static ExprNodeGenericFuncDesc hash(List<ExprNodeDesc> exps) {
+ assert exps.size() >= 2;
+ ExprNodeDesc hashExp = exps.get(0);
+ for (int i = 1; i < exps.size(); i++) {
+ List<ExprNodeDesc> hArgs = Arrays.asList(hashExp, exps.get(i));
+ hashExp = new ExprNodeGenericFuncDesc(TypeInfoFactory.intTypeInfo, new
GenericUDFMurmurHash(), "hash", hArgs);
Review comment:
Good catch @kgyrtkirk ! I've never noticed that we have two different
UDFs for hashing. Indeed having the same annotation can create quite some
confusion and difficult to debug problems. I guess your suggestion is to change
the annotation of GenericUDFMurmurHash to murmur_hash right?
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Issue Time Tracking
-------------------
Worklog Id: (was: 500618)
Time Spent: 0.5h (was: 20m)
> Use vectorizable expression to combine multiple columns in semijoin bloom
> filters
> ---------------------------------------------------------------------------------
>
> Key: HIVE-24221
> URL: https://issues.apache.org/jira/browse/HIVE-24221
> Project: Hive
> Issue Type: Improvement
> Components: Query Planning
> Environment:
> Reporter: Stamatis Zampetakis
> Assignee: Stamatis Zampetakis
> Priority: Major
> Labels: pull-request-available
> Time Spent: 0.5h
> Remaining Estimate: 0h
>
> Currently, multi-column semijoin reducers use an n-ary call to
> GenericUDFMurmurHash to combine multiple values into one, which is used as an
> entry to the bloom filter. However, there are no vectorized operators that
> treat n-ary inputs. The same goes for the vectorized implementation of
> GenericUDFMurmurHash introduced in HIVE-23976.
> The goal of this issue is to choose an alternative way to combine multiple
> values into one to pass in the bloom filter comprising only vectorized
> operators.
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