difference between Snapshot replication and transactional replication

_{Sunday, February 14, 2010 1:32 PM}

Hi All,
Can someone suggest the differences between snapshot and transactional replication. as far as i have seen, we use publisher, distributor and subscriber roles, able to choose different objects of the database, its columns. creation of roles, Push and Pull subscription are some of the steps identical for both of them.!

_{Tuesday, February 16, 2010 5:40 AM ✅Answered | 1 vote}

The differences are the mechanisms on how the data replicated from the publication to the subscriptions. For a snapshot replication, it has two agents during the replication process, snapshot agent and distribution agent; while transactional replication has an additional agent, Log Reader agent. By using log reader agent, it is not needed to apply a snapshot everytime for data synchronization since applying a whole snapshot is a cost intensive job. Log reader agent will monitor the transaction log changes of the publication and deliver the transactions to the distribution database, then distributor only needs to apply the transactions to the subscription. Comparing with snapshot replication, this wins far better performance on the time of data synchronization.

For more information, please refer to:
How Snapshot Replication Works
http://msdn.microsoft.com/en-us/library/ms151734.aspx
How Transactional Replication Works
http://msdn.microsoft.com/en-us/library/ms151706.aspx

Best regards,
Charles Wang
Please remember to mark the replies as answers if they help and unmark them if they provide no help

_{Tuesday, February 16, 2010 4:32 PM ✅Answered | 2 votes}

Snapshot Replication:

during the replication process snapshot replication will drop table from subscriber and recreate.  Snapshot replication we cannot schedule during the business hour. 

Transactional Replication:

Transactional replication it will not drop the table during the replication, in transactional replication log reader agent just capture the changes from transaction log and sending those change info to distribution database, from distribution database changes applying to  subscriber. 

Note: Transactional replication will drop the table if we configure 1st time, after that it will capture the changes from transaction log.

Rajeev R

_{Tuesday, February 16, 2010 5:51 AM}

Usage wise,
Snapshot replication is suited for small set of data or in frequently changing data.

Transactional replication is suited for large data set.Blog: http://dineshasanka.spaces.live.com

_{Tuesday, January 24, 2012 3:23 AM}

In snapshot replication, while generating snapshot we can select three options.

1.drop and recreate the object in subscriber

2.truncate the table

3. delete the data from the table.

this is even applicable to TR when we generate the snapshot first time.

the major difference is how the data replicate. for snapshot the complete data will flow from publisher to subscriber while in TR it is the changes which will replicate to the subscriber.