Discussion in 'SQL PL/SQL' started by monkey, Jun 7, 2014.
What would be the first row's address and the last one's?
Please, what is T_ROW T IN THAT EXAMPLE?
That example is simply indicating that it is possible to create a table with an explicitly-defined column that has a data type of ROWID and populate it with a ROWID value. Every table in Oracle has an implicitly defined ROWID column that always contains the location of the row. An explicitly-defined column could contain the ROWID of a different row in the database.
Theoretically I suppose you could use this to make one row point to the ROWID of a related row in the database -- either in the same table or a different one. It might allow for faster access than a foreign key since no index access would be required. The work to maintain it would probably outweigh any benefits, though.