kgyrtkirk commented on a change in pull request #1544:
URL: https://github.com/apache/hive/pull/1544#discussion_r542113182



##########
File path: ql/src/java/org/apache/hadoop/hive/ql/plan/ExprNodeDescUtils.java
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@@ -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:
       yes; excatly




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