Newbie at Replication

There aren't many primary keys on the tables in the Publishers. If I add primary keys to the tables on the replicated database, when I subscribe again to the Publications, will they disappear from my replicated database (i.e. will the schema be overwritten)?The response below is from a Merge replication perspective:

Firstly, after adding the new PKs to the tables at the Publisher, adding a new subscription to it will not overwrite the publisher schema. All reinitializing an existing subscriber will not overwrite the Publisher schema (It will however overwrite the subscriber schema, provided you ran the snapshot)

However if you want the added PKs to propagate to the subscriber, then you will fall into one of the cases below:

If you add the new PKs on the publisher before the snapshot is generated and delivered to the subscriber, the subscriber will get the new PKs.

However if the subscriber already has the snapshot and is synched up, and then you add the new PKs at the publisher, the subscriber will not get PKs incrementally on subsequent synchs. You will either need to explicitly create them at the subscriber, or add the PKs at the publisher, regenerate the snapshot, and reinitialize the subscriber.

Please refer to Books Online for furhter information on Initial Synchronization, Subsequent Synchronization, Incremental changes and replicating DDL changes.|||Yes it does help very much, thank you! By trial and error I arrived at the same answer. Thank you for the reference to the solution in Books Online. Sometimes I don't have the right keywords in my search.