Re: Function based indexes and index fast full scan

Hi,

As I remember it, the "Index FFS" plan becomes attractive if you have a db_file_multiblock_read_count of greater than 4.

I was explained to me that the Index FFS is like a FTS, and sequential prefetch is invoked.

In your example, with 40k rows at, using, say, 100 bytes per row on an 8k blocksize, there are 80 rows per block, and the whole index will reside in 500 data blocks.

You are right, I would expect a range scan to have less I/O. . . . Received on Sun Jun 30 2002 - 18:02:48 CDT