Обсуждение: Table inheritance and performance

I'm in the design stage of a database and I am thinking of using table
inheritance for the first time. However I've been wondering if table
inheritance would be all that useful and what, if any, performance
penalties there might be.

For example, say I have a parent table FRUITS and two children, APPLES
and ORANGES, where the APPPLES and ORANGES tables are identical.
Performance-wise would it be any different from having just one table,
FRUITS, and a column TYPE which would be a foreign key into a types
table (1 = APPLE, 2 = ORANGE, etc ...). Would using inheritance in this
case be a performance hit compared to a simple type column with lookup
table? Or would there be no penalty for using inheritance?

Thanks,

Jean-Christian Imbeault