Fix postgres compatibility bug

This commit is contained in:
Neil Johnson 2018-08-06 21:55:54 +01:00
parent 1911c037cb
commit e54794f5b6

View file

@ -43,14 +43,25 @@ class MonthlyActiveUsersStore(SQLBaseStore):
thirty_days_ago = (
int(self._clock.time_msec()) - (1000 * 60 * 60 * 24 * 30)
)
# Purge stale users
sql = "DELETE FROM monthly_active_users WHERE timestamp < ?"
txn.execute(sql, (thirty_days_ago,))
# If MAU user count still exceeds the MAU threshold, then delete on
# a least recently active basis.
# Note it is not possible to write this query using OFFSET due to
# incompatibilities in how sqlite an postgres support the feature.
# sqlite requires 'LIMIT -1 OFFSET ?', the LIMIT must be present
# While Postgres does not require 'LIMIT', but also does not support
# negative LIMIT values. So there is no way to write it that both can
# support
sql = """
DELETE FROM monthly_active_users
ORDER BY timestamp desc
LIMIT -1 OFFSET ?
WHERE user_id NOT IN (
SELECT user_id FROM monthly_active_users
ORDER BY timestamp DESC
LIMIT ?
)
"""
txn.execute(sql, (self.hs.config.max_mau_value,))