reference: https://www.gharchive.org/
how to use:

code:
SELECT REGEXP_EXTRACT(email, r'@(.*)') domain, COUNT(*) c
FROM (
SELECT REGEXP_EXTRACT(payload, r'([a-zA-Z0-9_.+-]+@[a-zA-Z0-9-]+\.[a-zA-Z0-9-.]+)') email
FROM `githubarchive.year.2019`
)
-- WHERE REGEXP_CONTAINS(email, r"@[a-zA-Z0-9-]+\.[a-zA-Z0-9-]")
WHERE REGEXP_CONTAINS(email, r"@[a-zA-Z0-9-]+\.edu")
GROUP BY 1
ORDER BY 2 DESC
LIMIT 500;
result - wordwide:

result - chinese universities:
