diff --git a/memory/src/main/scala/filodb.memory/format/vectors/Histogram.scala b/memory/src/main/scala/filodb.memory/format/vectors/Histogram.scala
index 53a803a0c..d1ba20463 100644
--- a/memory/src/main/scala/filodb.memory/format/vectors/Histogram.scala
+++ b/memory/src/main/scala/filodb.memory/format/vectors/Histogram.scala
@@ -83,7 +83,7 @@ trait Histogram extends Ordered[Histogram] {
 
       // now calculate quantile.  If bucket is last one and last bucket is +Inf then return second-to-last bucket top
       // as we cannot interpolate to +Inf.
-      if (bucket == numBuckets-1 && bucketTop(numBuckets - 1).isPosInfinity) {
+      if (bucket == numBuckets-1 && bucketEnd.isPosInfinity) {
         return bucketTop(numBuckets-2)
       } else if (bucket == 0 && bucketTop(0) <= 0) {
         return bucketTop(0) // zero or negative bucket
diff --git a/query/src/main/scala/filodb/query/exec/rangefn/AggrOverTimeFunctions.scala b/query/src/main/scala/filodb/query/exec/rangefn/AggrOverTimeFunctions.scala
index 9ee5dff50..ff39cbff2 100644
--- a/query/src/main/scala/filodb/query/exec/rangefn/AggrOverTimeFunctions.scala
+++ b/query/src/main/scala/filodb/query/exec/rangefn/AggrOverTimeFunctions.scala
@@ -390,7 +390,7 @@ class RateAndMinMaxOverTimeFuncHD(maxColId: Int, minColId: Int) extends ChunkedR
   def addChunks(tsVectorAcc: MemoryReader, tsVector: BinaryVectorPtr, tsReader: bv.LongVectorDataReader,
                 valueVectorAcc: MemoryReader, valueVector: BinaryVectorPtr, valueReader: VectorDataReader,
                 startTime: Long, endTime: Long, info: ChunkSetInfoReader, queryConfig: QueryConfig): Unit = {
-    // Do BinarySearch for start/end pos only once for both columns == WIN!
+    // Do BinarySearch for start/end pos only once for all columns == WIN!
     val startRowNum = tsReader.binarySearch(tsVectorAcc, tsVector, startTime) & 0x7fffffff
     val endRowNum = Math.min(tsReader.ceilingIndex(tsVectorAcc, tsVector, endTime), info.numRows - 1)
 
@@ -403,7 +403,7 @@ class RateAndMinMaxOverTimeFuncHD(maxColId: Int, minColId: Int) extends ChunkedR
       val maxVectPtr = info.vectorAddress(maxColId)
       maxFunc.addTimeChunks(maxVectAcc, maxVectPtr, bv.DoubleVector(maxVectAcc, maxVectPtr), startRowNum, endRowNum)
 
-      // Get valueVector/reader for max column
+      // Get valueVector/reader for min column
       val minVectAcc = info.vectorAccessor(minColId)
       val minVectPtr = info.vectorAddress(minColId)
       minFunc.addTimeChunks(minVectAcc, minVectPtr, bv.DoubleVector(minVectAcc, minVectPtr), startRowNum, endRowNum)