How to delete duplicate entries from a specific field by SQL query in DSpace?

I am using DSpace version 6.3 here. I discovered that I have created duplicate entries when performing a batch import. Using the SQL query from this answer, I managed to list all the duplicates in a given field. For this example, I am using the dc.subject field (metadata_field_id=57) to list items (dspace_object_id) that have duplicate values in dc.subject field.

Below is the query that I used:

SELECT metadata_value_id, dspace_object_id, text_value FROM (SELECT *, COUNT(*) OVER (PARTITION BY dspace_object_id, text_value) AS cnt FROM metadatavalue where metadata_field_id=57) e WHERE cnt > 1 

Below is the sample list generated from that query:

Based on the table above, you can see that there are 2 occurrences (others have more than 2) of a text_value in the same item (dspace_object_id).

My question is how can I delete the duplicate but retain the first occurrence? In the table above, rows with the following metadata_value_id should be deleted:

503021 503219 83574 <-- This should be deleted instead of 10800 because 10800 was put in (inserted) first. 531521 483882 <-- Should be deleted instead of 483879 because of the same reason above. 

I'm hoping to do this via SQL query alone because what I have done before is import this list to a Google spreadsheet, remove the duplicates there using a Remove Duplicates add-on, download it as a CSV, and then use that CSV to update the metadatavalue table.