While using multimaster replication often you would be bombarded with errors like “No data found”, “Unique Key Violated” etc .
These are purely data mismatch errors and a user intervention needed to resolve them.
I often come across these errors when we run applications at multiple sites which are part of same replication group/tables when they are designed to run at one replication site at any given time.
You can get list of these errors at DEFERROER view with transaction ids but there is no easy way to locate the parameters,columns and tables on which these errors occurred.
Thankfully there is a solution if you have EM installed.
We often get thousands of replication conflits/errors at current system. A resolution is generally looking at EM console and resolving each error manually. Please see examples below.
Using the DIFFERENCES Procedure
The DIFFERENCES procedure compares two replicas of a table, and determines all rows in the first replica that are not in the second and all rows in the second that are not in the first. The output of this procedure is stored in two user-created tables. The first table stores the values of the missing rows, and the second table is used to indicate which site contains each row.
Find out total number of error X’actions
SELECT COUNT ( * )
FROM (SELECT DEFERRED_TRAN_ID,
TO_CHAR (START_TIME, ‘DD-Mon-YYYY hh24:mi:ss’)
This call will delete all Errors from replication Queue i.e deferror & deftran
Delete all Errors from replication sites
Check if there are any errors "select * from deferror;"