[SPARK-9069] [SPARK-9264] [SQL] remove unlimited precision support for DecimalType

Romove Decimal.Unlimited (change to support precision up to 38, to match with Hive and other databases).

In order to keep backward source compatibility, Decimal.Unlimited is still there, but change to Decimal(38, 18).

If no precision and scale is provide, it's Decimal(10, 0) as before.

Author: Davies Liu <davies@databricks.com>

Closes #7605 from davies/decimal_unlimited and squashes the following commits:

aa3f115 [Davies Liu] fix tests and style
fb0d20d [Davies Liu] address comments
bfaae35 [Davies Liu] fix style
df93657 [Davies Liu] address comments and clean up
06727fd [Davies Liu] Merge branch 'master' of github.com:apache/spark into decimal_unlimited
4c28969 [Davies Liu] fix tests
8d783cc [Davies Liu] fix tests
788631c [Davies Liu] fix double with decimal in Union/except
1779bde [Davies Liu] fix scala style
c9c7c78 [Davies Liu] remove Decimal.Unlimited

1 files changed, 1 insertions, 1 deletions

diff --git a/mllib/src/test/scala/org/apache/spark/ml/attribute/AttributeSuite.scala b/mllib/src/test/scala/org/apache/spark/ml/attribute/AttributeSuite.scala
index c5fd2f9d5a..6355e0f179 100644
--- a/mllib/src/test/scala/org/apache/spark/ml/attribute/AttributeSuite.scala
+++ b/mllib/src/test/scala/org/apache/spark/ml/attribute/AttributeSuite.scala
@@ -218,7 +218,7 @@ class AttributeSuite extends SparkFunSuite {
     // Attribute.fromStructField should accept any NumericType, not just DoubleType
     val longFldWithMeta = new StructField("x", LongType, false, metadata)
     assert(Attribute.fromStructField(longFldWithMeta).isNumeric)
-    val decimalFldWithMeta = new StructField("x", DecimalType(None), false, metadata)
+    val decimalFldWithMeta = new StructField("x", DecimalType(38, 18), false, metadata)
     assert(Attribute.fromStructField(decimalFldWithMeta).isNumeric)
   }
 }