diff --git a/include/ircd/m/dbs.h b/include/ircd/m/dbs.h
index 597bfd1a8..bc83f2717 100644
--- a/include/ircd/m/dbs.h
+++ b/include/ircd/m/dbs.h
@@ -33,14 +33,17 @@ namespace ircd::m::dbs
 	extern db::column state_node;
 
 	// Lowlevel util
+	static const size_t ROOM_STATE_KEY_MAX_SIZE {id::MAX_SIZE + 256 + 256};
 	string_view room_state_key(const mutable_buffer &out, const id::room &, const string_view &type, const string_view &state_key);
 	string_view room_state_key(const mutable_buffer &out, const id::room &, const string_view &type);
 	std::pair<string_view, string_view> room_state_key(const string_view &amalgam);
 
+	static const size_t ROOM_JOINED_KEY_MAX_SIZE {id::MAX_SIZE + 256 + id::MAX_SIZE};
 	string_view room_joined_key(const mutable_buffer &out, const id::room &, const string_view &origin, const id::user &member);
 	string_view room_joined_key(const mutable_buffer &out, const id::room &, const string_view &origin);
 	std::pair<string_view, string_view> room_joined_key(const string_view &amalgam);
 
+	static const size_t ROOM_EVENTS_KEY_MAX_SIZE {id::MAX_SIZE + 1 + 8 + 8};
 	string_view room_events_key(const mutable_buffer &out, const id::room &, const uint64_t &depth, const event::idx &);
 	string_view room_events_key(const mutable_buffer &out, const id::room &, const uint64_t &depth);
 	std::pair<uint64_t, event::idx> room_events_key(const string_view &amalgam);
diff --git a/ircd/m/dbs.cc b/ircd/m/dbs.cc
index 9766bdc9e..676f19ade 100644
--- a/ircd/m/dbs.cc
+++ b/ircd/m/dbs.cc
@@ -243,7 +243,7 @@ ircd::m::dbs::_index__room_events(db::txn &txn,
                                   const string_view &new_root)
 {
 	const ctx::critical_assertion ca;
-	thread_local char buf[256 + 1 + 8 + 8];
+	thread_local char buf[ROOM_EVENTS_KEY_MAX_SIZE];
 	const string_view &key
 	{
 		room_events_key(buf, at<"room_id"_>(event), at<"depth"_>(event), opts.idx)
@@ -274,7 +274,7 @@ ircd::m::dbs::_index__room_joined(db::txn &txn,
 		return;
 
 	const ctx::critical_assertion ca;
-	thread_local char buf[512];
+	thread_local char buf[ROOM_JOINED_KEY_MAX_SIZE];
 	const string_view &key
 	{
 		room_joined_key(buf, at<"room_id"_>(event), at<"origin"_>(event), at<"state_key"_>(event))
@@ -328,7 +328,7 @@ ircd::m::dbs::_index__room_state(db::txn &txn,
 		return;
 
 	const ctx::critical_assertion ca;
-	thread_local char buf[768];
+	thread_local char buf[ROOM_STATE_KEY_MAX_SIZE];
 	const string_view &key
 	{
 		room_state_key(buf, at<"room_id"_>(event), at<"type"_>(event), at<"state_key"_>(event))
@@ -443,7 +443,7 @@ ircd::m::dbs::state_root(const mutable_buffer &out,
                          const event::idx &event_idx,
                          const uint64_t &depth)
 {
-	char keybuf[256 + 1 + 8 + 8]; const auto key
+	char keybuf[ROOM_EVENTS_KEY_MAX_SIZE]; const auto key
 	{
 		room_events_key(keybuf, room_id, depth, event_idx)
 	};
diff --git a/ircd/m/room.cc b/ircd/m/room.cc
index 5f4a5729b..08a0aca8c 100644
--- a/ircd/m/room.cc
+++ b/ircd/m/room.cc
@@ -474,7 +474,7 @@ ircd::m::room::messages::seek(const event::id &event_id)
 		depth = byte_view<uint64_t>(value);
 	});
 
-	char buf[m::state::KEY_MAX_SZ];
+	char buf[dbs::ROOM_EVENTS_KEY_MAX_SIZE];
 	const auto seek_key
 	{
 		dbs::room_events_key(buf, room.room_id, depth, event_idx)
@@ -487,7 +487,7 @@ ircd::m::room::messages::seek(const event::id &event_id)
 bool
 ircd::m::room::messages::seek(const uint64_t &depth)
 {
-	char buf[m::state::KEY_MAX_SZ];
+	char buf[dbs::ROOM_EVENTS_KEY_MAX_SIZE];
 	const auto seek_key
 	{
 		dbs::room_events_key(buf, room.room_id, depth)
@@ -664,8 +664,8 @@ const try
 			closure(event::fetch::index(unquote(event_id)));
 		});
 
-	char key[768];
 	auto &column{dbs::room_state};
+	char key[dbs::ROOM_STATE_KEY_MAX_SIZE];
 	column(dbs::room_state_key(key, room_id, type, state_key), [&closure]
 	(const string_view &value)
 	{
@@ -738,8 +738,8 @@ const
 			return closure(event::fetch::index(unquote(event_id), std::nothrow));
 		});
 
-	char key[768];
 	auto &column{dbs::room_state};
+	char key[dbs::ROOM_STATE_KEY_MAX_SIZE];
 	return column(dbs::room_state_key(key, room_id, type, state_key), std::nothrow, [&closure]
 	(const string_view &value)
 	{
@@ -767,8 +767,8 @@ const
 		(const string_view &event_id)
 		{});
 
-	char key[768];
 	auto &column{dbs::room_state};
+	char key[dbs::ROOM_STATE_KEY_MAX_SIZE];
 	return db::has(column, dbs::room_state_key(key, room_id, type, state_key));
 }
 
@@ -794,7 +794,7 @@ const
 	if(root_id)
 		return m::state::count(root_id, type);
 
-	char keybuf[768];
+	char keybuf[dbs::ROOM_STATE_KEY_MAX_SIZE];
 	const auto &key
 	{
 		dbs::room_state_key(keybuf, room_id, type)
@@ -926,7 +926,7 @@ const
 			return closure(event::fetch::index(unquote(event_id), std::nothrow));
 		});
 
-	char keybuf[768];
+	char keybuf[dbs::ROOM_STATE_KEY_MAX_SIZE];
 	const auto &key
 	{
 		dbs::room_state_key(keybuf, room_id, type)
@@ -957,7 +957,7 @@ const
 			return closure(unquote(key.at(1)));
 		});
 
-	char keybuf[768];
+	char keybuf[dbs::ROOM_STATE_KEY_MAX_SIZE];
 	const auto &key
 	{
 		dbs::room_state_key(keybuf, room_id, type)
@@ -1040,7 +1040,7 @@ const
 			return closure(event::fetch::index(unquote(event_id), std::nothrow));
 		});
 
-	char keybuf[768];
+	char keybuf[dbs::ROOM_STATE_KEY_MAX_SIZE];
 	const auto &key
 	{
 		dbs::room_state_key(keybuf, room_id, type, state_key_lb)
@@ -1150,7 +1150,7 @@ const
 			closure(event::fetch::index(unquote(event_id), std::nothrow));
 		});
 
-	char keybuf[768];
+	char keybuf[dbs::ROOM_STATE_KEY_MAX_SIZE];
 	const auto &key
 	{
 		dbs::room_state_key(keybuf, room_id, type)
@@ -1177,7 +1177,7 @@ const
 			closure(unquote(key.at(1)));
 		});
 
-	char keybuf[768];
+	char keybuf[dbs::ROOM_STATE_KEY_MAX_SIZE];
 	const auto &key
 	{
 		dbs::room_state_key(keybuf, room_id, type)
@@ -1393,7 +1393,7 @@ const
 		dbs::room_joined
 	};
 
-	char querybuf[512];
+	char querybuf[dbs::ROOM_JOINED_KEY_MAX_SIZE];
 	const auto query
 	{
 		dbs::room_joined_key(querybuf, room.room_id, origin)