If you have added any custom Data
fields then you can convert them to Small Text
to reduce row size.
kindly refer this document
https://docs.erpnext.com/docs/user/manual/en/maximum-number-of-fields-in-a-form#solution
Here i have deleted about 30 fields which was customily created but the database row size remains the same is there any other way rather than deleting the fields (which is already deleted from UI)directly from database