Re: A 'snapshot' of table data

A snapshot won't give an arbitrary number of users the ability to create multiple independent sets of the data at a given point in time. I think what the poster should use is "set transaction read only." This allows all reads until the transaction is ended to be performed as of the time the "set transaction read only" command was issued. This uses Oracle inherent multiversion consistent read mechanism.

In 9.x, I have heard that there is a new feature that allows consistent read of data *in the past*. If this is true, it is really cool. I can easily see how the same mechanism that is used to provide consistent reads now might be adapted to this purpose.

--
Jeremiah Wilton
http://www.speakeasy.net/~jwilton

On Thu, 24 May 2001, Daniel A. Morgan wrote:



> The answer to your question is contained within your Subject line. Use a

> snapshot, also known as a materialized view, and give the end-users the

> ability to refresh it.

>

> Stephen Bell wrote:

>

> > I have a requirement to be able to present an image of a table's data at

> > a specific point in time..this point in time would be determined by the

> > user...i.e. after they complete certain procedural requirements, they

> > would "freeze" the table (from their perspective)..the actual table

> > would still be open for transactions but we would need a snapshot of the

> > table at the point in time it was requested.

> >

> > There could be several times when the user might do this while

> > interacting with the application so I don't want an indefinite number of

> > table copies floating around...the real table and it's copies would

> > reside on the same server so the issue seems different from using oracle

> > snapshots..would temporary tables be the way to go?