TIBCO Designer - Timer based process to delete data from oracle table for last 50 days

[m k 2]

I am using TIBCO 5.14. In Tibco designer, i would like to create the following process

Timer based process runs every day lets say at 3:00am.

I have a jdbc query activity and have select statement which returns number of rows. For example 1 million records

I have jdbc update activity and have delete statement to delete based on number of days 50 and row numbers lets say 200,000. even though, select statement returns 1 millions records, if i try to delete at once, it may jdbc timeout so i want to  delete 200,000 and then go back and delete another 200,000 until it become zero.

can you please provide how can i achieve this? which loops i should use for which activity?