public Interface Pushable

Indicates the columns that must be returned by a read-write VTI's ResultSet. This method is called only during the runtime execution of the VTI, after it has been constructed and before the executeQuery() method is called. At compile time the VTI needs to describe the complete set of columns it can return.
The column identifiers contained in projectedColumns map to the columns described by the VTI's PreparedStatement's ResultSetMetaData. The ResultSet returned by PreparedStatement.executeQuery() must contain these columns in the order given. Column 1 in this ResultSet maps the the column of the VTI identified by projectedColumns[0], column 2 maps to projectedColumns[1] etc.
Any additional columns contained in the ResultSet are ignored by the database engine. The ResultSetMetaData returned by ResultSet.getMetaData() must match the ResultSet.

PreparedStatement's ResultSetMetaData column list {"id", "desc", "price", "tax", "brand"}
projectedColumns = { 2, 3, 5}
results in a ResultSet containing at least these 3 columns {"desc", "price", "brand"} The JDBC column numbering scheme (1 based) ise used for projectedColumns.

Parameters

vtiEnvironment:VTIEnvironment

The VTI context

projectedColumns:int[]

Columns being projected out

Returns:boolean

a boolean value

Exceptions

SQLException:

Error processing the request.