Did you create a backup of the old data before loading the current data? If not, why not . . . ?
Suggest you talk with your storage management people and see if there is a disaster recovery backup or other backup that has the old data and make a plan to recover it. Many (most?) organizations run full-volume backups periodically.
Thanks for your suggestion. Since this is a Dev data, i don't think that there will be some backup for my database. I will check with Storage mgmt team if they run any scripts for this at back end for all Dev databases.
I checked whether there is any Full image copy for my database. I could not find any.
Any other suggestions to recover my database would be great ?
If there is no backup i don't know of any way to get it back. . .
Can you re-run the processes that use some sequential data to insert/load into the missing table(s)?
If not, suggest you come up with a way to have the initial data available (after you recreate it) and make sure there is a periodic backup of your data so that you can get it back. Just because the storage management might not backup your test data is no reason for it not to be backed up.
Most organizations have realized that the IT developers are the most expensive department in the organization and not treating thier data as valuable as production is quite foolish. . .