Github user nareshpr commented on a diff in the pull request:
https://github.com/apache/incubator-carbondata/pull/641#discussion_r106112796
--- Diff:
integration/spark-common/src/main/scala/org/apache/carbondata/spark/util/CarbonScalaUtil.scala
---
@@ -194,4 +196,102 @@ object CarbonScalaUtil {
}
}
}
+
+ /**
+ * This method will validate a column for its data type and check
whether the column data type
+ * can be modified and update if conditions are met
+ *
+ * @param dataTypeInfo
+ * @param carbonColumn
+ */
+ def validateColumnDataType(dataTypeInfo: DataTypeInfo, carbonColumn:
CarbonColumn): Unit = {
+ carbonColumn.getDataType.getName match {
+ case "INT" =>
+ if (!dataTypeInfo.dataType.equals("bigint")) {
+ sys
+ .error(s"Given column ${ carbonColumn.getColName } with data
type ${
+ carbonColumn
+ .getDataType.getName
+ } cannot be modified. Int can only be changed to bigInt")
+ }
+ case "DECIMAL" =>
+ if (!dataTypeInfo.dataType.equals("decimal")) {
+ sys
+ .error(s"Given column ${ carbonColumn.getColName } with data
type ${
+ carbonColumn.getDataType.getName
+ } cannot be modified. Decimal can be only be changed to
Decimal of higher precision")
+ }
+ if (dataTypeInfo.precision <=
carbonColumn.getColumnSchema.getPrecision) {
+ sys
+ .error(s"Given column ${
+ carbonColumn
+ .getColName
+ } cannot be modified. Specified precision value ${
+ dataTypeInfo
+ .precision
+ } should be greater or equal to current precision value ${
+ carbonColumn.getColumnSchema
+ .getPrecision
+ }")
+ } else if (dataTypeInfo.scale <=
carbonColumn.getColumnSchema.getScale) {
+ sys
+ .error(s"Given column ${
+ carbonColumn
+ .getColName
+ } cannot be modified. Specified scale value ${
+ dataTypeInfo
+ .scale
+ } should be greater or equal to current scale value ${
+ carbonColumn.getColumnSchema
+ .getScale
+ }")
+ } else {
+ // difference of precision and scale specified by user should
not be less than the
+ // difference of already existing precision and scale else it
will result in data loss
+ val carbonColumnPrecisionScaleDiff =
carbonColumn.getColumnSchema.getPrecision -
+
carbonColumn.getColumnSchema.getScale
+ val dataInfoPrecisionScaleDiff = dataTypeInfo.precision -
dataTypeInfo.scale
+ if (dataInfoPrecisionScaleDiff < carbonColumnPrecisionScaleDiff)
{
+ sys
+ .error(s"Given column ${
+ carbonColumn
+ .getColName
+ } cannot be modified. Specified precision and scale values
will lead to data loss")
+ }
+ }
+ case _ =>
+ sys
+ .error(s"Given column ${ carbonColumn.getColName } with data
type ${
+ carbonColumn
+ .getDataType.getName
+ } cannot be modified. Only Int and Decimal data types are
allowed for modification")
+ }
+ }
+
+ /**
+ * This method will create a copy of the same object
+ *
+ * @param thriftColumnSchema object to be cloned
+ * @return
+ */
+ def createColumnSchemaCopyObject(thriftColumnSchema:
org.apache.carbondata.format.ColumnSchema)
--- End diff --
Done
---
If your project is set up for it, you can reply to this email and have your
reply appear on GitHub as well. If your project does not have this feature
enabled and wishes so, or if the feature is enabled but not working, please
contact infrastructure at [email protected] or file a JIRA ticket
with INFRA.
---
