Currently when IBM Unica campaign uploading the contacts to WCA for email send, customer is using sync keys. So the records will be always unique and in campaign, they also choose the option "Create new contact list for every run" in the email process box(campaign).

There is a defect logged with campaign to send the contact upload with "ADD_ONLY" option. According to WCA L3, add_only helps improve performance compare to add and update. Once the campaign fix sending contact upload with add only option, there is still room for improvement in WCA side.

Currently WCA locks the table whenever there is an add_only or add_and_update. I totally understand that we need to lock the table when there is a ADD_AND_UPDATE, to prevent data corruption/data integrity. However in this customer scenario, all the jobs will be send as ADD_ONLY and all the records will be added and no update. In this case, WCA should not lock the table and allow parallel processing of inserts into the table. This will not cause any data issue as all the records will be unique.

Once we have both the campaign(Defect) and WCA(Enhancement) is available, our hope is performance will be much better as the majority of the time is spent on waiting rather than execution of the job.