NetNews Usenet Archive 1992 #16/NN_1992_16.iso/spool/comp/database/oracle/1125

Internet Message Format | 1992-07-23 | 1.6 KB

Path: sparky!uunet!mcsun!news.funet.fi!hydra!klaava!cc.helsinki.fi!jaakola
From: [e-mail]
Newsgroups: comp.databases.oracle
Subject: Re: Using Views for BLOCKS?
Message-ID: <[e-mail]>
Date: 24 Jul 92 06:37:10 GMT
References: <[e-mail]>
Sender: [e-mail] (Uutis Ankka)
Organization: University of Helsinki
Lines: 29

In article <[e-mail]>, [e-mail] (Stephen Schow) writes:
> I have heard that SQL*FORMS performance is a little better if I create a
> view of a table and then base the form block on the view instead of
> directly on the table.
>
> Anyone have any experience to know if this is true or not?
If you have an one-to-one view from a single table, this is not true.
But if you have a base table and you must join data from several other
tables (i.e. you have and POST-QUERY trigger or POST-CHANGE triggers),
you can join the data in the view and avoid calling several SQL
statements for each fetched record during a query. This is very
important in client-server environments, particularly when clients are
PCs.

>
> ALSO,
>
> What if I created a view with a join and based a form on that view as
> if it was just one table.  Would I be able to update records and would
If the view is updatable, yes (see the manual on views).

> Oracle automatically update both the master and the detail records in the
> actual tables?
If the view fetches from many tables, the view most certainly is not
updatable. You have to make your own ON-LOCK and ON-UPDATE/DELETE/INSERT
triggers.
--
Juhani Jaakola
[e-mail]