Re: doubt on order of table scan

"Rene Nyffenegger" <rene.nyffenegger_at_gmx.ch> wrote in message news:dirph3$924$1_at_klatschtante.init7.net...
> What good is the index for if the entire table must be scanned anyway?

I think if there's where clause so the optimizer chooses the most convenient index based on statistics provided by ANALYZE in order to minimize i/o. Since I'm familiar with Sybase so I know it chooses the clustered index if it's exists where pages are sorted according to index and data & index are in the same pages in order to minimize I/O. I don't know if there's something similar in Oracle since I'm new to Oracle.

If there's no where clause so it follows page chaining (no index pages needed). Received on Sat Oct 15 2005 - 16:28:27 CDT