Re: Materialized Views: Refreshing same MV by 2 calls to DBMS_MVIEW.REFRESH at the same time.

AEH wrote:
> Current State:
> Currently we have a system that inserts records directly into a
> staging table directly after any of several tables are inserted,
> updated or deleted to/from. This is done by invoking the update
> functions in every trigger attached to these tables that force changes
> to the staging table. This staging table is part of a larger search.
>
> Research:
> My first response when seeing the code that creates the staging table
> was to as if there was a more elegant way to accomplish the same
> result. The existing code works but lacks documentation and the person
> who built it left the company without imparting knowledge of this to
> some else.
>
> I have explored several different ways to deal with this issue. Some
> are unworkable due to how the application layer works. Currently I
> have two possibilities, leave it as it is or design a materialized view
> that will replace the staging table in question.
>
> I've gone through the process of using the DBMS packages to determine
> if the Materialized view is possible and what type of refresh it could
> have.
>
> Because I am on an OLTP database the materialized view must be
> refreshed prior to the user has accessing the search to account to any
> recent changes they have made. I know that I can do an ON_DEMAND
> refresh by calling DBMS_MV.REFRESH for the materialized view. I also
> know that I have to allow for 2 users going doing a search at the same
> time.
>
> Question:
> Does the DBMS Materialized view functionality has any issues with being
> called at the same time, by 2 different users?
>
> References to the articles/documentation I have read available upon
> request.
> Thanks for your time!
> A.E. Harris
>

Why not use a view? A materialized view is a table, ultimately. You can query it, certainly, but if you haven't refreshed it, you will get old data.
And as readers don't block writers, writers don't block readers, and readers most certainly do not block readers, you can query anything you like. Unless you meant something different, of course.

-- 
Regards,
Frank van Bortel