How to recover deleted records with minimal downtime? In an OLTP environment that cannot tolerate downtime, suppose if 100 records are deleted from a table, how do we recover them?

One way to recover the deleted records is to restore the database and/or tablespace then rollforward to point-in-time.
I believe DB2 Recovery Expert is the best option.  

In the case of a dropped object, or recovery to a specific point in time, you should use the "Recovery" option.  The "undo SQL" option performs Log Analysis, which only affects data, not structure. 

Please check IBM's official webpage : DB2 Recovery Expert