Script to delete records from 5 big_data tables

Hi all, we need the script for customers, which will purge several tables with historical data. The tables have one parent table.

So t1 - parent (PK)

and t2...t5 - has FK to t1.PK, has constraints and indexes to PK.

There are several big tables from t1..t5:

t2 ~ 50 milllions rows

t3 ~ 70 milllions rows

t1 ~ 20 milllions rows

etc.

The condition to delete rows - is time, when t1 row was created.

We do not know how much data will customer delete (more than 50% or not), so we do not use replace and truncate steps.

To provide from ORA-30036: unable to extend segment by 8 in undo tablespace 'UNDO'