diff options
| -rw-r--r-- | changelog.d/16667.misc | 1 | ||||
| -rw-r--r-- | synapse/storage/databases/main/client_ips.py | 17 |
2 files changed, 8 insertions, 10 deletions
diff --git a/changelog.d/16667.misc b/changelog.d/16667.misc new file mode 100644 index 0000000000..51aeca9243 --- /dev/null +++ b/changelog.d/16667.misc @@ -0,0 +1 @@ +Reduce database load of pruning old `user_ips`. diff --git a/synapse/storage/databases/main/client_ips.py b/synapse/storage/databases/main/client_ips.py index d4b14aaebe..1df7731050 100644 --- a/synapse/storage/databases/main/client_ips.py +++ b/synapse/storage/databases/main/client_ips.py @@ -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 ) """ |