RE: SQL Views worth it?

From a performance standpoint, SQL views are no better than running the query directly over tables. IMO comparing views & LF's is like apples vs oranges.

-----Original Message-----
From: dlclark@xxxxxxxxxxxxxxxx [mailto:dlclark@xxxxxxxxxxxxxxxx]
Sent: Friday, August 24, 2018 2:10 PM
To: RPG programming on the IBM i (AS/400 and iSeries) <rpg400-l@xxxxxxxxxxxx>
Subject: Re: SQL Views worth it?

"RPG400-L" <rpg400-l-bounces@xxxxxxxxxxxx> wrote on 08/24/2018 02:10:54
PM:

I'm developing a new application and trying to have the DB do as much of

the work as possible.
So, I'm incorporating SQL Views but finding the throughput

underwhelming.

Granted that some of the views are based on other views (in keeping with

the attempt to have the DB do some work for me)
but it appears that every time a view is queried the views are rebuilt
by the OS.

I read somewhere that Views can be considered somewhat like logical
files, but at least logicals
can be set to have immediate updates as underlying physicals change.
Views have no such attribute settings.

I agree 100%. I am not impressed with DB2 SQL Views. Even adding
indexes doesn't improve their performance enough since, as you pointed
out, they are materialized at execution time. So, there is no way they
can perform as well as DDS Logical files. But I have heard some strong
adherents claim that SQL Views perform just as well as DDS Logical file.
Well, I disagree -- been their, got that T-shirt. Had to go with an MQT
to get the performance of a DDS Logical file except that MQT's are not
updatable.

Sincerely,

Dave Clark