Class ExplicitSchemaProjection


public class ExplicitSchemaProjection extends ReaderLevelProjection
Perform a schema projection for the case of an explicit list of projected columns. Example: SELECT a, b, c.

An explicit projection starts with the requested set of columns, then looks in the table schema to find matches. That is, it is driven by the query itself.

An explicit projection may include columns that do not exist in the source schema. In this case, we fill in null columns for unmatched projections.