Snapshot Rep. between 2 schemas in same instance

Question

Hi,
I need to have two copies of my data within one instance. One
copy is updateable by an admin user and the other copy is read-
only by other users. The problem is that I want to allow the
admin user to update the data without the others being affected
until the admin user decides that the new data is to be made
available i.e. normal users work with the old data until the
admin user is finished entering the new data.
My initial idea is to use read-only snapshot replication to
provide the normal users with snapshots of the admin user's
data. Then, when the admin user finishes entering new data a
refresh can be done and all the other users can then see the new
data.
Is this a sensible way to do things? Should I be using a second
instance? This would no doubt increase the licensing costs? I am
relatively new to Oracle so am not sure if there is a better way
to achieve what I need.
Thanks for any advice,
Grant Fitzgerald

Answer 1

Grant,
You really don't need two copies of the data or two instances of
Oracle to achieve this. You can achieve your goal by using an
appropriate transaction management strategy. You need only one
schema to hold all your data. The admin user could be given full
access to the data while all other users only get view access.
This can be achieved using roles and synonyms.
When a user updates/inserts/deletes data from a table those
changes cannot be seen by other users until the work is
COMMITTED. Therefore the admin user could carry out various
changes to the base data without other users seeing the changes.
When the admin user decides the changes are complete, he/she
could issue a COMMIT, which then makes the data available to all
other users. It really depends on the amount of changes being
made by the admin user each time and how long this takes, hours,
days, weeks?
This is probably the best approach and will eliminate the issues
surrounding replication and multiples instances. What do you
think?
Martin