SQL Clone
SQLServerCentral is supported by Redgate
 
Log in  ::  Register  ::  Not logged in
 
 
 


Replication -- Will blocking occur at the Subscriber like at the Publisher?


Replication -- Will blocking occur at the Subscriber like at the Publisher?

Author
Message
UncleBoris
UncleBoris
SSC-Enthusiastic
SSC-Enthusiastic (173 reputation)SSC-Enthusiastic (173 reputation)SSC-Enthusiastic (173 reputation)SSC-Enthusiastic (173 reputation)SSC-Enthusiastic (173 reputation)SSC-Enthusiastic (173 reputation)SSC-Enthusiastic (173 reputation)SSC-Enthusiastic (173 reputation)

Group: General Forum Members
Points: 173 Visits: 730
Hello, I have a table on Database A that is frequently updated by Application A.

Application B needs to frequently SELECT from this table in a time critical process, so obviously some blocking occurs.

I was thinking of Replicating the table to Database B and do the SELECT from that table.

What I am unsure of if I will get exactly the same symptoms i.e if an UPDATE lock occurs on Database A (Publisher) therefore blocking SELECTS then an UPDATE lock will also occur on Database B (Subscriber) therefore still blocking SELECTs...so basically more complexity for no gain!!!

Is this what would happen?

thanks
Orlando Colamatteo
Orlando Colamatteo
SSChampion
SSChampion (14K reputation)SSChampion (14K reputation)SSChampion (14K reputation)SSChampion (14K reputation)SSChampion (14K reputation)SSChampion (14K reputation)SSChampion (14K reputation)SSChampion (14K reputation)

Group: General Forum Members
Points: 14817 Visits: 14396
It could, but remember that the original statement is not what is replicated, the resulting CRUD operations are (minus the R's) so blocking should be reduced.

Said another way, imagine you issue a MERGE statement that has a 5-table join in the source and a very complex WHEN MATCHED clause to determine when to update. The MERGE could take 10 seconds to complete and cause lots of blocking, but it may only update 3 rows. In this scenario only 3 UPDATE statements would be Replicated and they would have the Primary Key in the WHERE clause which, all things being reasonable, should complete in well under a second on the Subscribers.

__________________________________________________________________________________________________
There are no special teachers of virtue, because virtue is taught by the whole community. --Plato
Go


Permissions

You can't post new topics.
You can't post topic replies.
You can't post new polls.
You can't post replies to polls.
You can't edit your own topics.
You can't delete your own topics.
You can't edit other topics.
You can't delete other topics.
You can't edit your own posts.
You can't edit other posts.
You can't delete your own posts.
You can't delete other posts.
You can't post events.
You can't edit your own events.
You can't edit other events.
You can't delete your own events.
You can't delete other events.
You can't send private messages.
You can't send emails.
You can read topics.
You can't vote in polls.
You can't upload attachments.
You can download attachments.
You can't post HTML code.
You can't edit HTML code.
You can't post IFCode.
You can't post JavaScript.
You can post emoticons.
You can't post or upload images.

Select a forum

































































































































































SQLServerCentral


Search