2 files changed, 12 insertions, 4 deletions
diff --git a/changelog.d/15316.misc b/changelog.d/15316.misc
new file mode 100644
index 0000000000..1f408739f0
--- /dev/null
+++ b/changelog.d/15316.misc
@@ -0,0 +1 @@
+As an optimisation, use `TRUNCATE` on Postgres when clearing the user directory tables.
\ No newline at end of file
diff --git a/synapse/storage/databases/main/user_directory.py b/synapse/storage/databases/main/user_directory.py
index 97f09b73dd..9fced4b997 100644
--- a/synapse/storage/databases/main/user_directory.py
+++ b/synapse/storage/databases/main/user_directory.py
@@ -698,10 +698,17 @@ class UserDirectoryBackgroundUpdateStore(StateDeltasStore):
"""Delete the entire user directory"""
def _delete_all_from_user_dir_txn(txn: LoggingTransaction) -> None:
- txn.execute("DELETE FROM user_directory")
- txn.execute("DELETE FROM user_directory_search")
- txn.execute("DELETE FROM users_in_public_rooms")
- txn.execute("DELETE FROM users_who_share_private_rooms")
+ # SQLite doesn't support TRUNCATE.
+ # On Postgres, DELETE FROM does a table scan but TRUNCATE is more efficient.
+ truncate = (
+ "DELETE FROM"
+ if isinstance(self.database_engine, Sqlite3Engine)
+ else "TRUNCATE"
+ )
+ txn.execute(f"{truncate} user_directory")
+ txn.execute(f"{truncate} user_directory_search")
+ txn.execute(f"{truncate} users_in_public_rooms")
+ txn.execute(f"{truncate} users_who_share_private_rooms")
txn.call_after(self.get_user_in_directory.invalidate_all)
await self.db_pool.runInteraction(
|
