Backup Considerations for a Publication Server

A publication server retains all replicated transactions within the transaction log of the published database until they are successfully transferred and preserved within the distribution database of the distribution server. Because of this, the transaction log of the publication server acts as an interim holding queue. Replicated transactions that have not yet been transferred are automatically preserved within the log.

A database dump of a published database may be accomplished at any time, because this does not affect the transaction log. However a transaction log dump of a published database will remove old transactions from the transaction log and must be coordinated with backup of the distribution database (as discussed in Backup Considerations for a Distribution Server, next in this chapter).

Because the transaction log also serves as an interim holding queue for replicated transactions, a transaction log dump of a published database does not truncate the log past the oldest replicated transaction that is not preserved within the distribution database of the associated distribution server.

If the transaction log of a published (replicated) database continues to fill and absolutely must be truncated, unsubscribe all subscribers of that database. This allows you to truncate past the oldest distributed transaction.