how to restore data in pr_history table for some columns
We are using Pega 6.3 sp1, on 20th Jan 2017 there was a need to do a DB cache clear and after doing the DB refresh--the cases(pyids) entering into the "pr_history" table they have 4 blank columns(ACTION,CASETYPE,STATUS,WORKGROUP). Which means this 4 columns values are blank for the cases after 20th Jan.Then we found the root cause that there is a declare expression which didn't triggered correctly so we revalidated and saved the declare rule and the corresponding activity on 12th June,2017. After doing this the problem solved(the 4 columns are populating for the cases that are getting created after 12th June).
Now the question is - can we restore the 4 columns values for the cases created between 20th Jan 2017 and 12th June 2017(there will be more than 50k cases between this time span). Is there any in built activity or process which does so.
As Santanu mentioned, there is no OOTB way/activity of achieving this. And moreover I am afraid that even by writing custom activity it would be very difficult as history information cannot be retrieved or formed from other data/tables.