Re: truncating snapshots

From: Mario Alberto Ramos Arellano <alramos_at_capufe.gob.mx>
Date: Mon, 17 Sep 2001 20:51:25 -0700
Message-ID: <F001.003912DA.20010917205017@fatcity.com>

Henry,
I think what you're talking about is Basic Replication. What's the purpose of truncating the snapshot between refreshes though?

Salu2

Mario Alberto Ramos

>>> abardeen1_at_yahoo.com 16/09/01 09:40 >>> Henry,

I'm not sure what you're trying to accomplish by truncating the snapshot. The whole point of the refresh process is to keep the snapshot in sync with the master site.

Presumably you are doing a CTAS off of the snapshot to do your manipulations, so what is the point in truncating the snapshot? I don't have a db handy to test whether Oracle detects that the snapshot has been truncated and does a complete refresh, but if the snapshot is very large it would probably be faster to drop and recreate it than to do a complete refresh.

A more detailed explanation of the process would help.

HTH,

• Anita
  • Henry Poras <Henry.Poras_at_ctp.com> wrote:
    > !! Please do not post Off Topic to this List !!
    >
    > I need to move the changes in a table from one
    > database to another. It
    > seemed that fast snapshots would be a good way to do
    > this as the database
    > will automatically keep track of the changes for me.
    > The question is that
    > once I move the data to the snapshot side, I need to
    > manipulate it, move it
    > into another table, and start the cycle again. This
    > means truncating the
    > snapshot between refreshes. I tried this on a test
    > system and it seesm to
    > work, but I don't think Oracle supports it. I don't
    > want updatable snapshots
    > as this is strictly one way movement of data. Has
    > anyone else tried this?
    > Are there any potential problems? I think I am just
    > truncating a table
    > underlying the snapshot view so I don't see what
    > could go wrong.
    >
    > Thanks.
    >
    > Henry
    > --
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  INET: alramos_at_capufe.gob.mx

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Received on Mon Sep 17 2001 - 22:51:25 CDT