Hi everyone

I would like to know if using several views for a complicated query is
slower than placing all the code in one large query.

I had heard that views were expensive in terms of performance, but I
find them used quite a bit.

Jeff

"Jeff User" <jeff31162 (AT) hotmail (DOT) com> wrote

query.
Jim

Jeff, there is no more noticeable overhead using a view than for a
regular query.

If it's a really complicated query requiring data that does not change
heavily (more than daily), then you could use Materialized Views (MV --
aka snapshots), with a fast refresh each night.

At a customer of mine, I changed their regular query to a MV, reducing
processing time from 129 minutes to 7 for a huge job each night. The
users then queried the MV and their users' requests returned in an
average of 23 seconds, down from 9 to 14 minutes depending on system load.

The only drawback is, it's a point-in-time snapshot as of the time it
was rebuilt, so the users have to understand it will not necessarily be
as of that moment. Depending on the complexity, you can also have it
fast refresh several times each day.

Jim
Principal Consultant
KCS
http://www.KotanConsulting.com


Jeff User wrote:

"Jeff User" <jeff31162 (AT) hotmail (DOT) com> wrote

If you consider MV's as mentioned by Jim K then have a look at
http://www.dizwell.com/prod/node/31