diff --git a/synapse/storage/events.py b/synapse/storage/events.py
index c81bc75eae..90e910f615 100644
--- a/synapse/storage/events.py
+++ b/synapse/storage/events.py
@@ -2093,6 +2093,27 @@ class EventsStore(SQLBaseStore):
# state_groups
# state_groups_state
+ # we will build a temporary table listing the events so that we don't
+ # have to keep shovelling the list back and forth across the
+ # connection. Annoyingly the python sqlite driver commits the
+ # transaction on CREATE, so let's do this first.
+ #
+ # furthermore, we might already have the table from a previous (failed)
+ # purge attempt, so let's drop the table first.
+
+ txn.execute("DROP TABLE IF EXISTS events_to_purge")
+
+ txn.execute(
+ "CREATE TEMPORARY TABLE events_to_purge ("
+ " event_id TEXT NOT NULL,"
+ " should_delete BOOLEAN NOT NULL"
+ ")"
+ )
+
+ # create an index on should_delete because later we'll be looking for
+ # the should_delete / shouldn't_delete subsets
+ txn.execute("CREATE INDEX ON events_to_purge(should_delete)")
+
# First ensure that we're not about to delete all the forward extremeties
txn.execute(
"SELECT e.event_id, e.depth FROM events as e "
@@ -2115,20 +2136,6 @@ class EventsStore(SQLBaseStore):
logger.info("[purge] looking for events to delete")
- # we build a temporary table listing the events so that we don't have
- # to keep shovelling the list back and forth across the connection.
-
- txn.execute(
- "CREATE TEMPORARY TABLE events_to_purge ("
- " event_id TEXT NOT NULL,"
- " should_delete BOOLEAN NOT NULL"
- ")"
- )
-
- # create an index on should_delete because later we'll be looking for
- # the should_delete / shouldn't_delete subsets
- txn.execute("CREATE INDEX ON events_to_purge(should_delete)")
-
should_delete_expr = "state_key IS NULL"
should_delete_params = ()
if not delete_local_events:
@@ -2339,11 +2346,6 @@ class EventsStore(SQLBaseStore):
(True,),
)
- # we're now done with the temporary table
- txn.execute(
- "DROP TABLE events_to_purge"
- )
-
# synapse tries to take out an exclusive lock on room_depth whenever it
# persists events (because upsert), and once we run this update, we
# will block that for the rest of our transaction.
@@ -2356,6 +2358,12 @@ class EventsStore(SQLBaseStore):
(topological_ordering, room_id,)
)
+ # finally, drop the temp table. this will commit the txn in sqlite,
+ # so make sure to keep this actually last.
+ txn.execute(
+ "DROP TABLE events_to_purge"
+ )
+
logger.info("[purge] done")
@defer.inlineCallbacks
|
