Then we get I to the whole "what does COST even mean" when costing the same
query but yet costs can't be compared.
I honestly think [sometimes? Often?] that Oracle has 'lost the plot' when
it comes to the CBO.
Chris
On Mon, Sep 23, 2019, 7:08 PM Clay Jackson (cjackson) <
Clay.Jackson@xxxxxxxxx> wrote:
As usual, Mark "hit the nail on the head!". If all Cost Accountants
thought and acted as he proposes, I would wholeheartedly agree.
Unfortunately, reality and human nature often intrude, and I think THAT's
where the issues come in. Far too many times, I've seen decisions made on
the basis of "least hard dollar cost", w/o considering the "hidden" or
"soft" costs.
One great example of that, WITHOUT starting a whole discussion on
"outsourcing" was the decision a former employer of mine made to outsource
"Account Provisioning" and "Security".
They told the displaced employees, "You have six months to train your
replacements REMOTELY" (i.e., they did NOT spend the money to bring the
"new" employees from the "low cost location" (the specific location, other
than the fact that it was 8 timezones away, is really irrelevant) to the
location of the current employees or vice-versa). When they executed the
switch, the time to provision a new account went from 6 hours to 3 days, as
the new folks learned all of "tribal knowledge" "the hard way"'; and the
error rate went from less than 1% rework to close to 75% rework.
Clay Jackson
Database Solutions Sales Engineer
clay.jackson@xxxxxxxxx
office 949-754-1203 mobile 425-802-9603
-----Original Message-----
From: Mark W. Farnham <mwf@xxxxxxxx>
Sent: Monday, September 23, 2019 2:35 PM
To: 'Mladen Gogala' <gogala.mladen@xxxxxxxxx>; Clay Jackson (cjackson) <
Clay.Jackson@xxxxxxxxx>; oracle-l@xxxxxxxxxxxxx
Subject: RE: Best course to understand why a bad plan is chosen by
optimizer
CAUTION: This email originated from outside of the organization. Do not
follow guidance, click links, or open attachments unless you recognize the
sender and know the content is safe.
Blush (okay, I don't really do that, but, thanks.)
Clay: Permission for re-use granted. I at least think that was original to
me.
Mladen, likewise, and further I suspect that *mostly* when we disagree
we're looking at different pieces of the elephant.
As for cost accounting the only thing I'm sure about is that it would be
done better if we didn't tax corporations and have to legally mesh those
views of the books.
But I don't want to get into an argument about how corporate taxes are
paid by customers on this technical forum, so I'll drop that without
further wind.
Of course meshing strategic provisioning with cost accounting as a check
on predictions is a useful component of achieving the business goal of
computer systems: 1) Reliable and quick enough most of the time to meet
service delivery promises to customers, safe and recoverable enough to
provide transaction integrity (which can be quite expensive to lose), and
all done reasonably close to the minimum cost (where reasonably is where it
would have cost more to plan better to reach a lower cost than the
difference.)
Experience guides toward erring a bit on the side of extra engineering to
avoid expensively retooling too much too often. I think that newfangled
method calls that "re-work." Experience also guides toward getting started
sometime well before the last possible outcome is modelled and tested in a
simulator (which is probably only justified rarely.)
I'll take both of you as my allies if ever the opportunity crops up. And
Lothar, too.
mwf
-----Original Message-----
From: Mladen Gogala [mailto:gogala.mladen@xxxxxxxxx]
Sent: Monday, September 23, 2019 2:45 PM
To: Clay Jackson (cjackson); mwf@xxxxxxxx; oracle-l@xxxxxxxxxxxxx
Subject: Re: Best course to understand why a bad plan is chosen by
optimizer
Hi Clay!
Comments in line:
On 9/23/19 1:19 PM, Clay Jackson (cjackson) wrote:
I've known Mark for a LONG time, and have ALWAYS been impressed with hiselegant "turn of phrase"!
I have never met Mark in my life and I am deeply sorry about it. I am
following his contributions on various Oracle forums with a sort of
fascination. I respect hist opinion deeply, even when I disagree with him.
few talks (I'm doing one in Dallas in a few weeks on "The Future of the DBA
I'm going to save this; and, with permission of course, may use it a
in a World of Autonomous Databases").
Databases are extremely complex, even if autonomous. I don't envision
being able to utilize a serious business database without having a DBA
anytime soon. Also, databases are getting larger. Backup and recovery of
50+ TB database is not as simple as it may look. Look at the databases
as modern airplanes. No robot can do what Sully Sullenberger has done.
Auto-pilot is available for the long time but I would be very hesitant to
fly an airplane which doesn't have a pilot on board.
mother was correct, when, in 1970, she predicted "Cost Accounting will be
I think sometimes we forget the "Engineering" ; and I'm 100% certain my
the ruin of civilization".
With all due respect, I disagree with your mother. Cost accounting is a
necessary evil. You can call me crazy, but I prefer the money to be spent
on my bonus over buying unnecessary software. My bonus is never unnecessary.
Clay Jackson
Database Solutions Sales Engineer
clay.jackson@xxxxxxxxx
office 949-754-1203 mobile 425-802-9603
