ProjectExec Unary Physical Operator¶

ProjectExec is a unary physical operator with support for Java code generation that represents Project logical operator at execution.

Creating Instance¶

ProjectExec takes the following to be created:

• NamedExpressions
• Child Physical Operator

ProjectExec is created when:

• BasicOperators execution planning strategy is executed (to plan Project logical operator)
• SparkPlanner is requested to pruneFilterProject
• DataSourceStrategy execution planning strategy is executed
• FileSourceStrategy execution planning strategy is executed
• DataSourceV2Strategy execution planning strategy is executed
• FileFormatWriter is requested to write

Executing Physical Operator¶

doExecute(): RDD[InternalRow]

doExecute is part of the SparkPlan abstraction.

doExecute requests the child physical plan to execute and mapPartitionsWithIndexInternal.

mapPartitionsWithIndexInternal¶

doExecute uses RDD.mapPartitionsWithIndexInternal.

mapPartitionsWithIndexInternal[U](
  f: (Int, Iterator[T]) => Iterator[U],
  preservesPartitioning: Boolean = false)

doExecute creates an UnsafeProjection for the named expressions and (the output of) the child physical operator.

doExecute requests the UnsafeProjection to initialize and maps over the internal rows (of a partition) using the projection.

Output Attributes¶

output: Seq[Attribute]

output is part of the QueryPlan abstraction.

output is the NamedExpressions converted to Attributes.