org.apache.hadoop.hive.ql.udf.generic
Class GenericUDFOPDivide

java.lang.Object
  org.apache.hadoop.hive.ql.udf.generic.GenericUDF
      org.apache.hadoop.hive.ql.udf.generic.GenericUDFBaseNumeric
          org.apache.hadoop.hive.ql.udf.generic.GenericUDFOPDivide

All Implemented Interfaces:

Closeable

public class GenericUDFOPDivide
extends GenericUDFBaseNumeric

Note that in SQL, the return type of divide is not necessarily the same as the parameters. For example, 3 / 2 = 1.5, not 1. To follow SQL, we always return a decimal for divide.

Nested Class Summary

Nested classes/interfaces inherited from class org.apache.hadoop.hive.ql.udf.generic.GenericUDF

GenericUDF.DeferredJavaObject, GenericUDF.DeferredObject

Field Summary

Fields inherited from class org.apache.hadoop.hive.ql.udf.generic.GenericUDFBaseNumeric

ansiSqlArithmetic, byteWritable, confLookupNeeded, converterLeft, converterRight, decimalWritable, doubleWritable, floatWritable, intWritable, leftOI, longWritable, opDisplayName, opName, resultOI, rightOI, shortWritable

Constructor Summary

GenericUDFOPDivide()

Method Summary

protected PrimitiveTypeInfo	deriveResultApproxTypeInfo() Default implementation for getting the approximate type info for the operator result.
protected DecimalTypeInfo	deriveResultDecimalTypeInfo(int prec1, int scale1, int prec2, int scale2) A balanced way to determine the precision/scale of decimal division result.
protected PrimitiveTypeInfo	deriveResultExactTypeInfo() Default implementation for getting the exact type info for the operator result.
protected PrimitiveTypeInfo	deriveResultExactTypeInfoAnsiSql()
protected PrimitiveTypeInfo	deriveResultExactTypeInfoBackwardsCompat()
protected DoubleWritable	evaluate(DoubleWritable left, DoubleWritable right)
protected HiveDecimalWritable	evaluate(HiveDecimal left, HiveDecimal right)

Methods inherited from class org.apache.hadoop.hive.ql.udf.generic.GenericUDFBaseNumeric

copyToNewInstance, deriveResultDecimalTypeInfo, evaluate, evaluate, evaluate, evaluate, evaluate, evaluate, getDisplayString, initialize

Methods inherited from class org.apache.hadoop.hive.ql.udf.generic.GenericUDF

close, configure, flip, getRequiredFiles, getRequiredJars, getUdfName, initializeAndFoldConstants

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Constructor Detail

GenericUDFOPDivide

public GenericUDFOPDivide()

Method Detail

deriveResultExactTypeInfo

protected PrimitiveTypeInfo deriveResultExactTypeInfo()

Description copied from class: GenericUDFBaseNumeric

Default implementation for getting the exact type info for the operator result. It worked for all but divide operator.

Overrides:

deriveResultExactTypeInfo in class GenericUDFBaseNumeric

Returns:

deriveResultExactTypeInfoAnsiSql

protected PrimitiveTypeInfo deriveResultExactTypeInfoAnsiSql()

deriveResultExactTypeInfoBackwardsCompat

protected PrimitiveTypeInfo deriveResultExactTypeInfoBackwardsCompat()

deriveResultApproxTypeInfo

protected PrimitiveTypeInfo deriveResultApproxTypeInfo()

Description copied from class: GenericUDFBaseNumeric

Default implementation for getting the approximate type info for the operator result. Divide operator overrides this.

Overrides:

deriveResultApproxTypeInfo in class GenericUDFBaseNumeric

Returns:

evaluate

protected DoubleWritable evaluate(DoubleWritable left,
                                  DoubleWritable right)

Overrides:

evaluate in class GenericUDFBaseNumeric

evaluate

protected HiveDecimalWritable evaluate(HiveDecimal left,
                                       HiveDecimal right)

Overrides:

evaluate in class GenericUDFBaseNumeric

deriveResultDecimalTypeInfo

protected DecimalTypeInfo deriveResultDecimalTypeInfo(int prec1,
                                                      int scale1,
                                                      int prec2,
                                                      int scale2)

A balanced way to determine the precision/scale of decimal division result. Integer digits and decimal digits are computed independently. However, when the precision from above reaches above HiveDecimal.MAX_PRECISION, interger digit and decimal digits are shrunk equally to fit.

Specified by:

deriveResultDecimalTypeInfo in class GenericUDFBaseNumeric