Leaf operators produce rows by communicating with a data source.

FakeData generates a flat relation using synthesized data. FakeData is used for testing.

FakeFileData reproduces a flat relation stored in tab-delimited format in a text file. FakeFileData is used for testing.

IteratorAsLeaf is used in dependent execution units. IteratorAsLeaf takes
an iterator that is specified in the execution unit’s parameter list and treats the iterator as a leaf operator. IteratorAsLeaf is used when a binary operator, for example a join, is applied to sibling relations within the same containing relation.

NoOp returns an empty relation. NoOp is used by the compiler to represent queries when the compiler determines that there are no results.

For more information about the ODA operator, see Displaying a data source query.

SortedOuterUnion allows multiple SELECT statements to be evaluated by a data source in a single round trip.

For more information about the SQL operator, see Displaying a data source query.