diff --git a/matrix/dbs_event_horizon.cc b/matrix/dbs_event_horizon.cc
index fd6013a68..5eb3580ee 100644
--- a/matrix/dbs_event_horizon.cc
+++ b/matrix/dbs_event_horizon.cc
@@ -143,97 +143,114 @@ ircd::m::dbs::desc::event_horizon
 // indexer
 //
 
+namespace ircd::m::dbs
+{
+	static void _index_event_horizon_resolve_one(db::txn &, const event &, const write_opts &, const event::idx &);
+}
+
 // NOTE: QUERY
 void
 ircd::m::dbs::_index_event_horizon_resolve(db::txn &txn,
                                            const event &event,
                                            const write_opts &opts)
 {
-	char buf[EVENT_HORIZON_KEY_MAX_SIZE];
 	assert(opts.appendix.test(appendix::EVENT_HORIZON_RESOLVE));
 	assert(opts.event_idx != 0);
 	assert(event.event_id);
+
+	char buf[EVENT_HORIZON_KEY_MAX_SIZE];
 	const string_view &key
 	{
 		event_horizon_key(buf, event.event_id)
 	};
 
-	auto it
+	auto it(dbs::event_horizon.begin(key)); do
 	{
-		dbs::event_horizon.begin(key)
-	};
+		static const size_t max{32};
 
-	for(; it; ++it)
-	{
-		const auto parts
+		size_t num(0);
+		event::idx event_idx[max];
+		for(; num < max && it; ++it)
 		{
-			event_horizon_key(it->first)
-		};
-
-		const auto &event_idx
-		{
-			std::get<0>(parts)
-		};
-
-		assert(event_idx != 0);
-		assert(event_idx != opts.event_idx);
-		const event::fetch _event
-		{
-			std::nothrow, event_idx
-		};
-
-		if(!_event.valid)
-		{
-			log::dwarning
-			{
-				log, "Horizon resolve for %s @%lu not possible @%lu",
-				string_view{event.event_id},
-				opts.event_idx,
-				event_idx,
-			};
-
-			continue;
+			event_idx[num] = std::get<0>(event_horizon_key(it->first));
+			num += event_idx[num] != 0;
 		}
 
-		log::debug
+		for(size_t i(0); i < num; ++i)
+			m::prefetch(event_idx[i]);
+
+		for(size_t i(0); i < num; ++i)
+			_index_event_horizon_resolve_one(txn, event, opts, event_idx[i]);
+	}
+	while(it);
+}
+
+// NOTE: QUERY
+void
+ircd::m::dbs::_index_event_horizon_resolve_one(db::txn &txn,
+                                               const event &event,
+                                               const write_opts &opts,
+                                               const event::idx &event_idx)
+{
+	assert(event_idx != 0);
+	assert(event_idx != opts.event_idx);
+
+	const event::fetch _event
+	{
+		std::nothrow, event_idx
+	};
+
+	if(!_event.valid)
+	{
+		log::dwarning
 		{
-			log, "Horizon resolve for %s @%lu; remisé %s @%lu",
+			log, "Horizon resolve for %s @%lu not possible @%lu",
 			string_view{event.event_id},
 			opts.event_idx,
-			string_view{_event.event_id},
 			event_idx,
 		};
 
-		// Make the references on behalf of the future event
-		write_opts _opts;
-		_opts.op = opts.op;
-		_opts.event_idx = event_idx;
-		_opts.appendix.reset();
-		_opts.appendix.set(appendix::EVENT_REFS);
-		_opts.appendix.set(appendix::ROOM_REDACT);
-		_opts.appendix.set(appendix::ROOM_HEAD_RESOLVE);
-		_opts.event_refs = opts.horizon_resolve;
-		_opts.interpose = &txn;
-		write(txn, _event, _opts);
-
-		// Delete the event_horizon entry after resolving.
-		thread_local char buf[EVENT_HORIZON_KEY_MAX_SIZE];
-		const string_view &key
-		{
-			event_horizon_key(buf, event.event_id, event_idx)
-		};
-
-		db::txn::append
-		{
-			txn, dbs::event_horizon,
-			{
-				opts.op == db::op::SET?
-					db::op::DELETE:
-					db::op::SET,
-				key
-			}
-		};
+		return;
 	}
+
+	log::debug
+	{
+		log, "Horizon resolve for %s @%lu; remisé %s @%lu",
+		string_view{event.event_id},
+		opts.event_idx,
+		string_view{_event.event_id},
+		event_idx,
+	};
+
+	// Make the references on behalf of the future event
+	write_opts _opts;
+	_opts.op = opts.op;
+	_opts.event_idx = event_idx;
+	_opts.appendix.reset();
+	_opts.appendix.set(appendix::EVENT_REFS);
+	_opts.appendix.set(appendix::ROOM_REDACT);
+	_opts.appendix.set(appendix::ROOM_HEAD_RESOLVE);
+	_opts.event_refs = opts.horizon_resolve;
+	_opts.interpose = &txn;
+	write(txn, _event, _opts);
+
+	// Delete the event_horizon entry after resolving.
+	thread_local char buf[EVENT_HORIZON_KEY_MAX_SIZE];
+	const string_view &key
+	{
+		event_horizon_key(buf, event.event_id, event_idx)
+	};
+
+	db::txn::append
+	{
+		txn, dbs::event_horizon,
+		{
+			opts.op == db::op::SET?
+				db::op::DELETE:
+				db::op::SET,
+			key
+		}
+	};
 }
 
 void