Yes, the majority big of optimization wins comes down business logic and
schema. Often it's not possible to do that.
and yes, Dan's method is a lot of work IMO thus why I love having software
doing most of the tedious grunt work. Yeah, when I read Dan's book I
thought it was cool, but so time consuming, that I would rarely do it, but
having some software to do a lot of the tedious work makes it much more fun.
Now that I bought my own copy, I plan to start looking into Visual SQL
Tuning again and try and blog on it.
It really stuck home when I was at Embarcadero and a customer sent in 3
problem queries that Oracle mis-optimized. Using Dan's method it was easy
to see what the solutions were. One of the hardest for Oracle optimizer was
a query that had only 4 tables but the most efficient path was to join the
first two tables then join the second two tables and then join the result
set. Oracle only joins in one table at a time so this isn't a method it
would find, but using subqueries and hints one could force the optimzer to
follow that path.
On Mon, Nov 26, 2018 at 9:06 PM Harmandeep Singh <singh.bedi@xxxxxxxxx>
wrote:
I follow Dan Tow " Tree Diagram " approach when sql is bit longer and it
best . Nothing beats it
Otherwise tuning sql based on explain plan and run time plan with costing
information is easy.
SQL tuning is all about understanding business logic of sql and
intercation with developers and business users sometimes
Regards
Harmandeep
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On Tue, Nov 27, 2018 at 12:54 AM kyle Hailey <kylelf@xxxxxxxxx> wrote:
Does anyone follow Dan Tow's methods from "SQL Tuning" and/or use Visual
SQL Tuning in DB Optimizer?
Dan's method is super insightful but it's a lot of work That's why I had
the DB Optimizer group at Embarcadero invest so much time into automating
Dan's method with "Visual SQL Tuning" so it would do much of the hard work
for the user.
If any one is interested, it looks like the black Friday sale on DB
Optimizer for 50% off is still available today:
DB Optimizer for Oracle available today (black Friday) at 50% off for
$357 with discount code QUACKFRIDAY50
https://www.idera.com/buynow/onlinestore
I just bought myself to have a copy just in case I need it. Not doing
much SQL tuning these days, but it's cool to have when needed.
VST is the unique feature to DB Optimizer bit it also does it's own ASH
sampling and works optionally on SQL Server, Sybase and DB2
