There are two ways to achieve this:
1. Set the parameter SP_OCT_REPLICATE_DDL to either 3 or 1.
Then apply the DDL change on the Source database.
The DDL change will replicated and applied to the Target table.
2. Carry out the following steps of manually applying the DDL on the Source and Target table:
a. Quiet the Source table (make sure there are no open transactions being done on it).
b. Issue a Flush on Source:
sp_ctrl> flush o.SID -- where SID is the Source database SID.
The Flush command will send a token message through the SharePlex queues to Target and Post will be stopped.
This serves as a reference point after which the table became quiet for Source users.
c. Execute the DDL chnage on the Source table.
d. Make a copy of the currently active config file and activate the copy.
This will update the object cache for Source table and later on for Target table when the object cache message reaches Post.
The object cache is SharePlex's way to represent table structure as it exists in the database.
e. Let users back on the Source table.
f. Execute the DDL change on the Target table.
g. Start Post that was earlier stopped due to flush.
