Question about efficiency of Views

Hi there,

Suppose I have created a view, and then perform a select statement against the view, with some kind of a WHERE clause.

My question is this: does the Oracle engine first perform the entire query as delineated in the view script, and then perform a sub-select from the view as indicated by the WHERE clause, or is the engine smart enough to substitue the WHERE condition immediately?

IOW, is there one pass or two passes at the data? Or are they equivalent in terms of efficiency?

TIA Pete Received on Wed Jul 07 1999 - 00:06:58 CDT