Does Replication Agent locks the database?

Hi,
Does the first synchronization(Replication Agent) while setting up merge
replication locks both the publisher and subscriber databases or the
databases can be used while the first synchronization is taking place?
If first synchronization does not lock the databases, will the changes that
have taken place at both the ends be merged later on, when synchronization
is complete?
Thanks
Anukul
Anukul,
there is no exclusive lock on the database, if that is what you are
referring to. There is a shared lock on the database as there would be on
any connection. As far as I know, there aren't exclusive locks held on the
table during the snapshot generation in merge replication. There are
page-level shared locks which'll prevent updates while the snapshot of a
particular page is being generated, but concurrent reads are compatible. In
transactional there is the option to use concurrent snapshot processing
where concurrent changes can occur during the snapshot generation, but not
so in merge or snapshot replication.
Rgds,
Paul Ibison SQL Server MVP, www.replicationanswers.com
(recommended sql server 2000 replication book:
http://www.nwsu.com/0974973602p.html)
|||Hi Paul:
I am talking about Replication Agent, which runs after snapshot agent.
Replication Agnet does the syncronization.
Please suggest.
Thanks,
Anukul
"Paul Ibison" <Paul.Ibison@.Pygmalion.Com> wrote in message
news:OLV3bsFGFHA.3888@.TK2MSFTNGP12.phx.gbl...
> Anukul,
> there is no exclusive lock on the database, if that is what you are
> referring to. There is a shared lock on the database as there would be on
> any connection. As far as I know, there aren't exclusive locks held on the
> table during the snapshot generation in merge replication. There are
> page-level shared locks which'll prevent updates while the snapshot of a
> particular page is being generated, but concurrent reads are compatible.
In
> transactional there is the option to use concurrent snapshot processing
> where concurrent changes can occur during the snapshot generation, but not
> so in merge or snapshot replication.
> Rgds,
> Paul Ibison SQL Server MVP, www.replicationanswers.com
> (recommended sql server 2000 replication book:
> http://www.nwsu.com/0974973602p.html)
>
|||My understanding is that the merge agent works with
batches of records and each separate batch is treated as
a transaction, but the combined synchronization process
is not held under a global transaction. In this case, an
edit to a record on a batch already processed would be
acceptable and would enter MSmerge_contents.
Rgds,
Paul Ibison SQL Server MVP, www.replicationanswers.com
(recommended sql server 2000 replication book:
http://www.nwsu.com/0974973602p.html)