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InterpretedProjection

InterpretedProjection is a Projection.

Creating Instance

InterpretedProjection takes the following to be created:

InterpretedProjection is created when:

  • HiveGenericUDTF is requested to eval
  • HiveScriptTransformationExec is requested to processIterator
  • SparkScriptTransformationExec is requested to processIterator
  • UserDefinedGenerator is requested to initializeConverters

Demo

// HACK: Disable symbolToColumn implicit conversion
// It is imported automatically in spark-shell (and makes demos impossible)
// implicit def symbolToColumn(s: Symbol): org.apache.spark.sql.ColumnName
trait ThatWasABadIdea
implicit def symbolToColumn(ack: ThatWasABadIdea) = ack

import org.apache.spark.sql.catalyst.dsl.expressions._
val boundRef = 'hello.string.at(4)

import org.apache.spark.sql.catalyst.expressions.{Expression, Literal}
val expressions: Seq[Expression] = Seq(Literal(1), boundRef)

import org.apache.spark.sql.catalyst.expressions.InterpretedProjection
val ip = new InterpretedProjection(expressions)
scala> println(ip)
Row => [1,input[4, string, true]]