What do you need to know about merge replication?

What do you need to know about merge replication?

Subscribers need to receive data, make changes offline, and later synchronize changes with the Publisher and other Subscribers. Each Subscriber requires a different partition of data. Conflicts might occur and, when they do, you need the ability to detect and resolve them.

How to configure transactional replication in SQL Server?

In SQL Server Management Studio, you must connect to the publisher and subscriber by using a login that is a member of the sysadmin fixed server role. For more information on this role, see Server-level roles.

What happens to rowguid column in Merge Replication?

Merge Replication. If the table is dropped from the publication, the rowguid column is removed; if an existing column was used for tracking, the column is not removed. A filter must not include the rowguidcol used by replication to identify rows. The newid () function is provided as a default for the rowguid column,…

How to create merge publication in SQL Server?

In this section, you create a merge publication by using SQL Server Management Studio to publish a subset of the Employee, SalesOrderHeader, and SalesOrderDetail tables in the AdventureWorks2012 sample database. These tables are filtered with parameterized row filters so that each subscription contains a unique partition of the data.

Merge replication requires that each published table have a ROWGUIDCOL column. If a ROWGUIDCOL column does not exist in the table before the Snapshot Agent creates the initial snapshot files, the agent must first add and populate the ROWGUIDCOL column.

What is the default logging file for Merge Replication?

Merge Replication automatically generates ReplMerge.log file which is ON by default. The minimal default logging may provide enough detail to resolve issue without needing to collect verbose log or Profiler trace.

How does synchronization affect the performance of a merge agent?

When synchronization occurs, the Merge Agent might need to read and transfer the entire data row from a Publisher or Subscriber. If the row contains columns that use LOBs, this process can require additional memory allocation and negatively impact performance even though these columns may not have been updated.

How to check replication performance in SQL Server?

Use Replication Monitor to get overall view of Replication performance. Add –OUTPUT to Merge Agent to identify which step (stored procedure) in the Merge processes is failing or taking longest time. Merge Replication automatically generates ReplMerge.log file which is ON by default.

How to add rowguid to every table in Merge Replication?

To accomplish this: Merge replication adds the column rowguid to every table, unless the table already has a column of data type uniqueidentifier with the ROWGUIDCOL property set (in which case this column is used).

How to create replication in SQL Server management studio?

Now let us create SQL Server merge replication and add these tables to the merge publication. Login to server using SQL Server Management studio -> Navigate to the SQL Server replication folder -> click on Local publications -> right click -> click on New Publication. Please refer to the below image.

When does replication resume if a connection is dropped?

Does replication resume if a connection is dropped. Yes. Replication processing resumes at the point at which it left off if a connection is dropped. If you are using merge replication over an unreliable network, consider using logical records, which ensures related changes are processed as a unit.

Can you use replication in SQL Server management studio?

Replication is not supported on SQL Server instances that are more than two versions apart. For more information, see Supported SQL Server Versions in Replication Topology. In SQL Server Management Studio, you must connect to the publisher and subscriber by using a login that is a member of the sysadmin fixed server role.

How to create a replication agent in SQL Server?

Specify server_name\\instance_name for a named instance of SQL Server on that server. Is the name of the Publisher database. Is the name of the publication. This parameter is only valid if the publication is set to always have a snapshot available for new or reinitialized subscriptions.

Is the merge article a download only article?

Merge Article is Download-Only Download-only articles are designed for applications with data that is not updated at Subscribers. For more information, see Optimize Merge Replication Performance with Download-Only Articles.

How does merge agent work in SQL Server?

The Merge Agent applies the initial snapshots to the Subscribers. It also merges incremental data changes that occurred at the Publisher or Subscribers after the initial snapshot was created, and detects and resolves any conflicts according to rules you configure.

How to synchronize a pull subscription in SQL Server?

Start the Merge Agent to transfer replication objects and download the latest changes from the Publisher. For more information, see Synchronize a Pull Subscription. Ensure that the schema and data exist on the subscription database. This can be done by restoring a backup of the publication database at the Subscriber.

How to change column level tracking in Merge Replication?

Navigate to the publisher, right-click it and select View conflicts. Select the conflict table and click OK to view details. Now let us change the tracking level to the column-level tracking. Navigate to the publication, right-click it and select Publisher properties.

When to use identity range management in Merge Replication?

When adding a new table to Merge Replication, you need to select the Identity Range Management option for synchronization. If any column has an identity property, IDENTITY (1,1), as a PRIMARY KEY for a table then it will create conflicts.

How are identity ranges managed in Merge Replication?

Merge Replication Identity ranges are managed by the Publisher and propagated to Subscribers by the Merge Agent (in a republishing hierarchy, ranges are managed by the root Publisher and the republishers). The identity values are assigned from a pool at the Publisher.