Speed up pruning of `user_ips` table (#16667)

Silly query planner
erikj/gha_auto_fixup
Erik Johnston 2023-11-29 11:54:42 +00:00 committed by GitHub
parent 6f2be7794e
commit df366966b4
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2 changed files with 8 additions and 10 deletions

1
changelog.d/16667.misc Normal file
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Reduce database load of pruning old `user_ips`.

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@ -465,18 +465,15 @@ class ClientIpWorkerStore(ClientIpBackgroundUpdateStore, MonthlyActiveUsersWorke
#
# This works by finding the max last_seen that is less than the given
# time, but has no more than N rows before it, deleting all rows with
# a lesser last_seen time. (We COALESCE so that the sub-SELECT always
# returns exactly one row).
# a lesser last_seen time. (We use an `IN` clause to force postgres to
# use the index, otherwise it tends to do a seq scan).
sql = """
DELETE FROM user_ips
WHERE last_seen <= (
SELECT COALESCE(MAX(last_seen), -1)
FROM (
SELECT last_seen FROM user_ips
WHERE last_seen <= ?
ORDER BY last_seen ASC
LIMIT 5000
) AS u
WHERE last_seen IN (
SELECT last_seen FROM user_ips
WHERE last_seen <= ?
ORDER BY last_seen ASC
LIMIT 5000
)
"""