Hi,
after upgrade to 19c from 11g we got issue with performance on partition tables where the partition key column is filtered using value from Function.
This started to generate explain plan with partition list ALL
edw_business_date = md.get_parameter_data('BUSINESS_DATE')
If we change it to select from dual the explain plan is OK, uses partition list SINGLE
edw_business_date = (select md.get_parameter_data('','','BUSINESS_DATE') from dual )
Our problem is that the filter is hardcoded on many places in the ETL so it's not that easy to use this workaround.
Thx a lot