• There will be no performance impact if you want to keep " Delta log retention to 3000". However, it will increase the storage cost so it's not advisable to use a large number until really needed for the business use cases.
• The default delta.logRetentionDuration is 30 days.
• You need to use ALTER table command to modify the existing property value.

%sql

ALTER TABLE table_name

SET TBLPROPERTIES ('delta.logRetentionDuration' = '<number_of_days> days')