Removal of Components: drop

Syntax

op [ drop comp {, comp }* ]

Input parameters

op	the operand
comp	a Component to drop

Examples of valid syntaxes

DS_1 [ drop Me_2, Me_3 ]

Semantics for scalar operations

This operator cannot be applied to scalar values.

Input parameters type

op

dataset

comp

name<component>

Result type

result

dataset

Additional Constraints

All the Components comp must belong to the input Data Set op.

The Components comp cannot be Identifiers in op.

Behaviour

The operator takes as input a Data Set (op) and some Component names of such a Data Set (comp). These Components can be Measures or Attributes of op but not Identifiers. The operator drops the specified Components and maintains all the other Components of the Data Set. This operation corresponds to a projection in the usual relational join semantics (specifying which columns will be projected out).