Does Carbondata store measure type by double?

[cenyuhai]

Hi, all:
     I am working on https://issues.apache.org/jira/browse/CARBONDATA-374
     I encounter a problem:
     The datatype of column is smallint , but it becomed double after loading from carbon




Caused by: java.lang.ClassCastException: java.lang.Double cannot be cast to java.lang.Long
        at scala.runtime.BoxesRunTime.unboxToLong(BoxesRunTime.java:110)
        at org.apache.spark.sql.catalyst.expressions.BaseGenericInternalRow$class.getLong(rows.scala:42)
        at org.apache.spark.sql.catalyst.expressions.GenericMutableRow.getLong(rows.scala:248)
        at org.apache.spark.sql.catalyst.expressions.GeneratedClass$SpecificUnsafeProjection.apply(Unknown Source)
        at org.apache.spark.sql.CarbonScan$$anonfun$1$$anon$1.next(CarbonOperators.scala:179)
        at org.apache.spark.sql.CarbonScan$$anonfun$1$$anon$1.next(CarbonOperators.scala:174)
        at scala.collection.Iterator$$anon$11.next(Iterator.scala:328)
        at scala.collection.Iterator$$anon$11.next(Iterator.scala:328)
        at scala.collection.Iterator$class.foreach(Iterator.scala:727)
        at scala.collection.AbstractIterator.foreach(Iterator.scala:1157)
        at scala.collection.generic.Growable$class.$plus$plus$eq(Growable.scala:48)
        at scala.collection.mutable.ArrayBuffer.$plus$plus$eq(ArrayBuffer.scala:103)
        at scala.collection.mutable.ArrayBuffer.$plus$plus$eq(ArrayBuffer.scala:47)
        at scala.collection.TraversableOnce$class.to(TraversableOnce.scala:273)
        at scala.collection.AbstractIterator.to(Iterator.scala:1157)
        at scala.collection.TraversableOnce$class.toBuffer(TraversableOnce.scala:265)
        at scala.collection.AbstractIterator.toBuffer(Iterator.scala:1157)
        at scala.collection.TraversableOnce$class.toArray(TraversableOnce.scala:252)
        at scala.collection.AbstractIterator.toArray(Iterator.scala:1157)
        at org.apache.spark.rdd.RDD$$anonfun$collect$1$$anonfun$12.apply(RDD.scala:927)
        at org.apache.spark.rdd.RDD$$anonfun$collect$1$$anonfun$12.apply(RDD.scala:927)
        at org.apache.spark.SparkContext$$anonfun$runJob$5.apply(SparkContext.scala:1858)
        at org.apache.spark.SparkContext$$anonfun$runJob$5.apply(SparkContext.scala:1858)
        at org.apache.spark.scheduler.ResultTask.runTask(ResultTask.scala:66)
        at org.apache.spark.scheduler.Task.run(Task.scala:89)
        at org.apache.spark.executor.Executor$TaskRunner.run(Executor.scala:227)
        at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1142)
        at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:617)
        at java.lang.Thread.run(Thread.java:745)