Where to get the file size of Work Order Attachment

I have created this query to pull the attachments for Work Order, I need to get the file size for each attachment.

Is the object_size the right column to use to know the file sizes of the attachments?

SELECT
TO_CHAR(w.last_update_date, 'YYYY-MM') AS month,
COUNT(CASE
WHEN d.datatype_code = 'WEB_PAGE'
THEN w.work_order_id
END) AS WO_WEB_PAGE_COUNT,

COUNT(CASE

    WHEN d.datatype_code = 'FILE'

    THEN w.work_order_id

END) AS WO_FILE_COUNT,


COUNT(CASE

    WHEN d.datatype_code = 'TMURI'

    THEN w.work_order_id

END) AS WO_TMURI_COUNT,