Thanks everyone who responded. I will research, capture statements, etc. I
got dragged into other issues Monday am!
On Mon, May 1, 2017 at 9:02 AM, Stefan Koehler <contact@xxxxxxxx> wrote:
sorry i do not get it.
The new type of histograms (including new collection - NDV for frequency
and "Top-N" histograms) are mainly implemented by DBMS_STATS and the cost
based optimizer has just slightly enhanced its arithmetic for it. The
clustering factor enhancement (table_cached_blocks) has already been
with 188.8.131.52 (back-port).
These are just little enhancements of the CBO and far away from a
"complete re-write" - especially not justifying "My usual advice to the
to wait for the first major patch set of the version 12.2".
Oracle's 12.1 CBO is more than stable for production.
Independent Oracle performance consultant and researcher
Upcoming online seminar: http://tinyurl.com/17-06-13-Shared-Pool-Internals
Mladen Gogala <gogala.mladen@xxxxxxxxx> hat am 1. Mai 2017 um 14:22geschrieben:
Well, there are several more changes you didn't mention: new type of
histograms, much larger histograms and a new way to calculate clustering