The “activate config” command has the options SCN or SEQNO which stand for SCN # (System Change #) or redo log sequence # respectively. The option is for starting replication from a particular SCN or log sequence #. If the purpose is to start replication from a point in time with a goal of incomplete recovery of target, then the above question has significance.
Here are the implications of providing inconsistent or incorrect value of SCN or SEQNO option in the “activate config” command
1. If the SCN or SEQNO provided to the command is less than the last one already applied to the target, this would result in either double posting or unique constraint violation errors (ORA-0001) depending on whether the object(s) have unique constraints enabled.
2. If the SCN or SEQNO provided to the command is more than the one that has been applied to the target the last time, this would result in target devoid of data. The effect will only show up once SharePlex stumbles upon those missing data and would consequently complain about out of sync.
3. If the SCN or SEQNO does not exist in the database, then the command will simply fail as follows:
Invalid number provided: nnnnnnnnnnnnnnnn
There will be no other implications except that the command will need to be re-issued with correct SCN #
See SharePlex Reference Guide for details on the command options.
