A synchronization scope is a logical grouping of objects that must be
synchronized as a unit.
The metadata that is maintained by each participant that describes all
the changes it has seen. In its simplest form, known as a watermark, a
knowledge item is a clock vector that consists of pairs of replica keys
and replica tick counts.
After you define the synchronization scope, you provision the database
to create a change-tracking and metadata management infrastructure that
consists of metadata tables, triggers, and stored procedures.
How To: Provision for Synchronization Using Snapshot Initialization
Sync Framework Tips and Troubleshooting
- Use snapshot initialization to create and initialize multiple SQL
Server Compact databases in your synchronization community. Snapshot
initialization offers much faster performance for setting up
multiple SQL Server Compact databases than provisioning each one
individually. And the API is simple, too! Here’s an article that
tell you how to do this:
- Use backup and restore (with post-restore fixup) to create and
initialize multiple large SQL Server databases in your
synchronization community. If you are setting up a synchronization
community that contains copies of a large SQL Server database,
performance will be better if you use backup and restore to create
the database copies instead of an initial synchronization. Here’s an
article that tells you how to do this:
- Don’t use TRUNCATE TABLE to modify a table that is synchronized.
This is because, while TRUNCATE TABLE is in effect a DELETE
statement, it does not activate the trigger used to update the
change tracking metadata, so the deletion is invisible to Sync
Framework and will not be sent to other replicas.
- To find a list of the scopes that are currently provisioned in a
database, query the scope_info table. The scope_info table
contains information about each scope, including the scope name.
- When a table in a SQL Server Compact database is initialized through
synchronization, the seed and increment of its identity columns are
always set to 0 and 1, respectively, regardless of how they are set
on the server database. If you need to insert rows locally in the
client database you must first set the identity seed and increment
to appropriate values or manually specify the identity column value,
otherwise new rows will have duplicate identity values and row
insertion will fail. The identity seed and increment can be set with
the following query, which sets the seed value to 10 and the
increment to 1:
ALTER TABLE ExampleTable ALTER COLUMN
Sync Framework 4.0
C:\Program Files (x86)\Microsoft SDKs\Microsoft Sync
Sync Framework provides snapshot, download-only, upload-only, and
bidirectional synchronization for client and server scenarios:
Ø Snapshot and download-only synchronization are typically used to
store and update reference data, such as a product list, on a client.
Data changes that are made at the server are downloaded to the client
database during synchronization. Snapshot synchronization completely
refreshes data every time that the client is synchronized. This is
appropriate when you do not want to track incremental changes or the
server cannot do so. Download-only synchronization downloads only the
incremental changes that have occurred since the previous
Ø Upload-only synchronization is typically used to insert data, such
as a sales order, on a client. Inserts and other changes to data that
are made in the client database are uploaded to the server during
Ø Bidirectional synchronization is typically used for data, such as
customer contact information, that can be updated at the client and
server. Any conflicting changes must be handled during synchronization.
Additional samples are available in the Sync Framework SDK and on Code
其一地点上出Orcale ,SQL Express等的例子
Database Sync – SQL Server and SQL Compact 2-Tier
Database Sync – Oracle and SQL Compact 2-Tier