1 files changed, 5 insertions, 2 deletions
diff --git a/sql/catalyst/src/main/scala/org/apache/spark/sql/catalyst/expressions/aggregate/HyperLogLogPlusPlus.scala b/sql/catalyst/src/main/scala/org/apache/spark/sql/catalyst/expressions/aggregate/HyperLogLogPlusPlus.scala
index b6bd56cff6..1d218da6db 100644
--- a/sql/catalyst/src/main/scala/org/apache/spark/sql/catalyst/expressions/aggregate/HyperLogLogPlusPlus.scala
+++ b/sql/catalyst/src/main/scala/org/apache/spark/sql/catalyst/expressions/aggregate/HyperLogLogPlusPlus.scala
@@ -20,8 +20,6 @@ package org.apache.spark.sql.catalyst.expressions.aggregate
 import java.lang.{Long => JLong}
 import java.util
 
-import com.clearspring.analytics.hash.MurmurHash
-
 import org.apache.spark.sql.AnalysisException
 import org.apache.spark.sql.catalyst.InternalRow
 import org.apache.spark.sql.catalyst.expressions._
@@ -48,6 +46,11 @@ import org.apache.spark.sql.types._
  * @param relativeSD the maximum estimation error allowed.
  */
 // scalastyle:on
+@ExpressionDescription(
+  usage = """_FUNC_(expr) - Returns the estimated cardinality by HyperLogLog++.
+    _FUNC_(expr, relativeSD=0.05) - Returns the estimated cardinality by HyperLogLog++
+      with relativeSD, the maximum estimation error allowed.
+    """)
 case class HyperLogLogPlusPlus(
     child: Expression,
     relativeSD: Double = 0.05,