YOU ARE USING MERGE REPLICATION TO MAKE YOUR USER AUTHENTICATION D...

13. You are using merge replication to make your user authentication database

highly available. The database has a single table that is shown in Example A.

The replication has been running for several months without issue. Your repli-

cation has begun failing, giving a unique index violation. What should you do

to correct the problem? Your business processes require that each username

remain unique within the system, and that users use their e-mail addresses for

their usernames.

Example A: Merge Replication

CREATE TABLE Authentication(UserId INT PRIMARY KEY IDENTITY(1,1),UserName NVARCHAR(255),Password NVARCHAR(100),Active BIT)GOCREATE UNIQUE INDEX IX_Authentication_UserName ON dbo.Authentication(UserName)INCLUDE (Password, UserId, Active)WITH (FILLFACTOR=60)

A. Mark the subscriber for reinitialization, and run the snapshot agent.

B. Identify the rows that are causing the violation and delete both rows from

the servers.

C. Identify the rows that are causing the violation, then identify which UserId

is being used by the customer within the rest of your business processes,

then modify the UserName value of the invalid row to a different value.

D. Delete the subscriber and re-create the subscription.

The correct answer is C. This solution will cause the least amount of

downtime for the environment, and the least inconvenience to your

customers. By using either solution A or D any new records that were

created on the subscriber after the offending row was entered would be

lost. Using solution B would cause the user to lose access to the system