Consolidation - Changing replicated data in a central subscribing site
Hi all,
I am new to replication and have a few questions.
1) Are there any "hooks" available to insert processing when a subscriber is about to copy data from a replicating site?
2) Is it possible for a subscriber to change only his local copy of the data - without replicating the changes back to the publisher?
I realise that once the data changes in one place it isn't really replicated anymore, and I realise that my limited knowledge of the subject might well mean I'm not even asking the right questions. Therefore, I shall try to describe as best I can my scenario.
I wish to use many servers for transactional input (to distribute the workload) and use replication to publish the inputted data to a subscribing central site. One of the tables I wish to replicate has an identity column as primary key, but the records should otherwise be unique - i.e. no two records should differ only in the value of the key. Another table, which should also be replicated, uses this id value as a foreign key.
I can use the identity increment and seed to guarantee no key violations will occur when copying data to the central server. However, there is another issue: Several servers can create the same record but with different id values.
I need to "merge" such records by deleting duplicate entries in the table with the identifier as primary key, and update the foreign keys correspondingly. To clarify (I hope!), here's an example of what data I might have on the central site after copying data from two input sites:
TRANSACTION table
amount = 200, metadata_id = 1001 // Replicated from server INPUT_1
amount = -117, metadata_id = 2001 // Replicated from server INPUT_2
METADATA table:
id=1001 Actitiy=Sales, Country=USA
id=2001 Activity=Sales, Country=USA
What I would like is basically for the central site to identify that metadata 2001 is really the same as metadata 1001, update the foreign key in the TRANSACTION record accordingly and not import (or delete, if this "merging" is done in a post-treatment) the duplicate metadata record.
If anyone can offer any advice on how to achieve this I would appreciate your input.
