Re: snapshots of remote views

From: Thomas J Kyte <tkyte_at_us.oracle.com>
Date: 1995/12/11
Message-ID: <4ag1f3$856_at_inet-nntp-gw-1.us.oracle.com>#1/1


joe_at_access1.digex.net (Joe Nardone) wrote:

>Thomas J Kyte (tkyte_at_us.oracle.com) wrote:
>: joe_at_access1.digex.net (Joe Nardone) wrote:
>:
>: >Thomas Orth (orth_at_delphi.com) wrote:
>: >: I am attempting to create an interface with another vendors proprietary
 [snip]
>: >: system, does anyone have any experience/suggestions? Much appreciated.
>: >:
>: >: Tom Orth
>: >: orth_at_delphi.com
 

>: >I don't believe you can fast refresh the base tables either
>: >under 7.0.16 (need 7.1 or greater). Since you can't upgrade, you may
>: >need to do full refreshes.
>:
>: Fast refresh has been around since 7.0. You don't need 7.1 or greater to do a
>: fast refresh.
 

>You're right. My mistake. However, to do fast refresh you have to
>install triggers on certain tables. (After-insert, I believe). However,
>because 7.0 only allows 1 type of trigger per table, if you already
>have after-insert (or after-update) triggers on your tables you're
>screwed as far as fast refresh goes.

Correct, 7.0 only allowed one trigger per event (eg: 1 before, 1 before for each row, 1 after for each row, and 1 after). To perform a fast refresh you would need to move any code resident in an AFTER FOR EACH FOR trigger into the end of the BEFORE FOR EACH ROW trigger (other then having a larger trigger, this has the same effect) since the fast refresh will need a snapshot log and the snapshot log is maintained via an after for each row trigger. you aren't really screwed, you get the *same* effects by placing the code in the BEFORE trigger. The multiple same type triggers added in 7.1 simply make this easier but don't allow you to do anything you couldn't already accomplish.

>
>=------------------------------------------------------------------=
>Joe Nardone <joe_at_access.digex.net>
>"Now that I have my coffee, I'm ready to watch radar."

Thomas Kyte
tkyte_at_us.oracle.com
Oracle Government Received on Mon Dec 11 1995 - 00:00:00 CET

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