State 0 for domain change involving replica?

[StevenMenefee1]

We have 2 geodatabases, Work and View (a replica of Work).  There are 5 versions under the Work geodatabase.  As a precaution we always compress Work to State 0 before we do any changes to domains.  My question is...is that really necessary?  If we don't delete the versions, and don't go to state 0, can we still make modifications to domains in the geodatabase...and can we compare replica schema's to get those changes into the View replica?

[HeatherMcCracken]

Correct - there is no need to get to State 0 for schema synchronization, or for replication in general for that matter. 

For a versioned geodatabase in general, the important thing is to get an effective compress to maintain good performance. We have a white paper called "Replication and compress" which you might find useful.  It gives an overview of how replication uses versions, and about how to get an effective compress while there are replicas in your system.

Blog post: http://blogs.esri.com/esri/arcgis/2008/11/25/geodatabase-replication-and-compress/
White paper: http://resources.esri.com/help/9.3/geodatabase/Blog/GDB_Rep_Compress.pdf

Hope this helps!
-Heather

[StevenMenefee1]

Okay great, thank you!  A follow-up question though.  If we do a schema sync or a regular sync, do all users need to be completely out of the replica geodatabase?  Or, do we just need to make sure no one is editing anything in the replica geodatabase?  Or does it not matter at all and we can sync regardless of who's connected to the replica?

[HeatherMcCracken]

Just think of Replication as another editor on your system.
So, the same considerations you make when changing the schema of your data outside of replication apply.  You will need a schema lock on the tables that will have their schema's changed.  So, not all the tables/fc's that are involved in the replica - just those that will be affected.

-Heather

[StevenMenefee1]

Okay...one final question!  If it's just a simple sync, with no schema changes at all....do end users have to be disconnected?  Currently when we sync to our View replica we make sure everyone is disconnected except the ArcGISSOC user that we found isn't affected by the sync (our flex portal is simply updated).  However, we weren't sure how end users who might be in the middle of an export (as an example) of a feature class we sync to would be impacted (i.e. the export fails or is corrupt).

[HeatherMcCracken]

End users do NOT have to be disconnected.  Replication was designed for a multi-user data base, so all should be good here.

Also - to help ease your mind about the impact of errors on the system.  Replication was designed to be fault tolerant.  So if something errors or goes down during an operation, for example there is a power outage during export or sync, replication will leave your database in a consistent state.  Nothing will be committed, it will just roll back to the state it was in before the operatioin - and you will just simply perform the operation again.

Hope this info helps - good luck!
-Heather