Statistics extensions

[Mladen Gogala]

I had a discussion with Mark Powell on another forum. Just for the record,
whenever a function based index is created on 11.2 (I don't have 11.1
available), a statistics extension is created as well. Using "FOR ALL
HIDDEN COLUMNS SIZE 254" will collect statistics (height based histograms
with 254 buckets) for all such extensions and help the query executions.
That is a very little advertised feature of the 11G version.

--
Mladen Gogala
http://mgogala.freehostia.com

[John Hurley]

Mladen:

# That is a very little advertised feature of the 11G version.

If curious about 12c hunt down Maria's presentation on new stuff in
the optimizer.

A whole bunch of new stuff is going to be jumping in ... including
switching execution plans in flight ( think just nested join over to
hash join in first release of 12c ). Also optimizer can create
extended statistics on the fly ( between columns ) even when you do
not generate them explicitly.

Lots of learning in store for the 12c optimizer and statistics!

[Mladen Gogala]

On Thu, 11 Oct 2012 12:26:40 -0700, John Hurley wrote:


> Lots of learning in store for the 12c optimizer and statistics!

Unfortunately, Oracle isn't very forthcoming with the literature and beta
versions, so nothing to do there, until the new version is released.

[John Hurley]

Mladen:

# Unfortunately, Oracle isn't very forthcoming with the literature and

beta versions, so nothing to do there, until the new version is
released.

...

All the sessions from OOW 2012 are locatable and abstracts/etc
searchable and in many cases the powerpoints etc are already
available.

Sure they have the standard caveats of "this is not yet a released
product so everything may change ... but ... " ...

The search interface for locating that content leaves a whole lot to
be desired however ...

[ddf]

It would be nice to provide a URL for those of us who don't have time
to go plodding through the web to find it.


David Fitzjarrell

[Mladen Gogala]

On Mon, 15 Oct 2012 08:30:31 -0700, ddf wrote:

> It would be nice to provide a URL for those of us who don't have time
> to go plodding through the web to find it.
>
>
> David Fitzjarrell

The best thing that I have about 12c is this:
http://myexpospace.com/oracle2012/SessionFiles/CON8429_PDF_8429_0001.pdf
It's a presentation by Tom Kyte

[John Hurley]

David:

# It would be  nice to provide a URL for those of us who don't have

time to go plodding through the web to find it.

A little cheese with your whine?

Looks like some of the presentations are not yet released as
collateral material ... probably many things 12c related ...

[ddf]

It's not a whine although you may be condescending enough to believe that. It was a request for some common courtesy since you posted these items were available on-line.


David Fitzjarrell

[John Hurley]

David:

# It was a request for some common courtesy since you posted these
items were available on-line.

Just kidding man ... yikes ... like I noted ( at least once if not
twice already in this thread ) ... searching for the presentations
from Oracle Open World is not very easy.

Step 1: Go to Open World http://www.oracle.com/openworld/index.html

Step 2: Tools ( under red top bar mid way on page is a drop down menu
when you scroll over it ) pick Virtual Collateral Rack

That leads you to a not very good searching tool ... you can put in
words like "Maria Colgan" and click search ...

Then you get a list of sessions ... like CON8455 and CON8457 etc ...

If you click on the description/link of CON8455 you get taken to a
page that has details on the session and in this case has a download
link for the pdf for the presentation.

The CON8457 session though ( on the new 12c stuff ) does not have a
download link ... probably still "confidential" ...

I could one could compile a list of links for the relevant session
pdfs ( or at least for the one that are available ).

I do not think that Oracle wants to provide the material like that
however ... they probably want you to use the ugly search process ...
so ( as I noted earlier ) its a YOYO ... You are On Your Own ...

[ddf]

Knowing WHERE to search is the key point here and it is not intuitive with this lacklustre search 'engine' (it's probably a two-cycle knock-off from Lawn Boy).

I do appreciate the direction as I'd probably never have found any of the sessions without it. I'm certain others appreciate it as well.


David Fitzjarrell

[John Hurley]

David:

# Knowing WHERE to search is the key point here and it is not

intuitive with this lacklustre search 'engine' (it's probably a two-
cycle knock-off from Lawn Boy).

It is really really horrible isn't it ...

Sorry I thought more people were already familiar with looking at
presentations and sessions from Open World ... they do ( eventually )
make almost everything presented available in one format or another.

Then it is matter of finding motivation and time to go through some of
it ( so many good speakers though ) ...

[ddf]

It isn't the motivation that is the issue -- it's the time I don't have to search with engines that don't search for items I only know of by speaker or by vague topic. We are in the process of migrating to Exadata and that, at the moment, is taking the bulk of my time. With no SMEs available in-house and a copy of Kerry Osborne's excellent Exadata text at my side I've been having to learn the machine on my own (which makes for long nights at the keyboard 'playing' with the db servers, the storage servers, cellcli, storage indexes and the like) my day is pretty well spent by the time 1 AM rolls around. Apparently the work is paying off so I continue my Exadata journey.

Thankfully I enjoy what I do.


David Fitzjarrell