I have SQL to get project key,issue key and attachment id's,looking for attachment size in byes in jira version 8.20.5
Example :
Project Key , Issuekey , Attachment ID, attachmentsize in bytes
SELECT
p.pkey AS project_key,
ji.issuenum AS issue_key,
fa.id AS attachment_id
FROM
project p
JOIN
jiraissue ji ON p.id = ji.project
JOIN
fileattachment fa ON ji.id = fa.issueid