diff --git a/src/database.rs b/src/database.rs
index 7a17e53..e0f9eec 100644
--- a/src/database.rs
+++ b/src/database.rs
@@ -24,13 +24,14 @@ use rocket::{
     request::{FromRequest, Request},
     Shutdown, State,
 };
-use ruma::{DeviceId, RoomId, ServerName, UserId};
+use ruma::{DeviceId, EventId, RoomId, ServerName, UserId};
 use serde::{de::IgnoredAny, Deserialize};
 use std::{
-    collections::{BTreeMap, HashMap},
+    collections::{BTreeMap, HashMap, HashSet},
     convert::TryFrom,
     fs::{self, remove_dir_all},
     io::Write,
+    mem::size_of,
     ops::Deref,
     path::Path,
     sync::{Arc, Mutex, RwLock},
@@ -261,7 +262,12 @@ impl Database {
                 userroomid_highlightcount: builder.open_tree("userroomid_highlightcount")?,
 
                 statekey_shortstatekey: builder.open_tree("statekey_shortstatekey")?,
+
+                shortroomid_roomid: builder.open_tree("shortroomid_roomid")?,
+                roomid_shortroomid: builder.open_tree("roomid_shortroomid")?,
+
                 stateid_shorteventid: builder.open_tree("stateid_shorteventid")?,
+                shortstatehash_statediff: builder.open_tree("shortstatehash_statediff")?,
                 eventid_shorteventid: builder.open_tree("eventid_shorteventid")?,
                 shorteventid_eventid: builder.open_tree("shorteventid_eventid")?,
                 shorteventid_shortstatehash: builder.open_tree("shorteventid_shortstatehash")?,
@@ -438,6 +444,334 @@ impl Database {
 
                 println!("Migration: 5 -> 6 finished");
             }
+
+            fn load_shortstatehash_info(
+                shortstatehash: &[u8],
+                db: &Database,
+                lru: &mut LruCache<
+                    Vec<u8>,
+                    Vec<(
+                        Vec<u8>,
+                        HashSet<Vec<u8>>,
+                        HashSet<Vec<u8>>,
+                        HashSet<Vec<u8>>,
+                    )>,
+                >,
+            ) -> Result<
+                Vec<(
+                    Vec<u8>,          // sstatehash
+                    HashSet<Vec<u8>>, // full state
+                    HashSet<Vec<u8>>, // added
+                    HashSet<Vec<u8>>, // removed
+                )>,
+            > {
+                if let Some(result) = lru.get_mut(shortstatehash) {
+                    return Ok(result.clone());
+                }
+
+                let value = db
+                    .rooms
+                    .shortstatehash_statediff
+                    .get(shortstatehash)?
+                    .ok_or_else(|| Error::bad_database("State hash does not exist"))?;
+                let parent = value[0..size_of::<u64>()].to_vec();
+
+                let mut add_mode = true;
+                let mut added = HashSet::new();
+                let mut removed = HashSet::new();
+
+                let mut i = size_of::<u64>();
+                while let Some(v) = value.get(i..i + 2 * size_of::<u64>()) {
+                    if add_mode && v.starts_with(&0_u64.to_be_bytes()) {
+                        add_mode = false;
+                        i += size_of::<u64>();
+                        continue;
+                    }
+                    if add_mode {
+                        added.insert(v.to_vec());
+                    } else {
+                        removed.insert(v.to_vec());
+                    }
+                    i += 2 * size_of::<u64>();
+                }
+
+                if parent != 0_u64.to_be_bytes() {
+                    let mut response = load_shortstatehash_info(&parent, db, lru)?;
+                    let mut state = response.last().unwrap().1.clone();
+                    state.extend(added.iter().cloned());
+                    for r in &removed {
+                        state.remove(r);
+                    }
+
+                    response.push((shortstatehash.to_vec(), state, added, removed));
+
+                    lru.insert(shortstatehash.to_vec(), response.clone());
+                    Ok(response)
+                } else {
+                    let mut response = Vec::new();
+                    response.push((shortstatehash.to_vec(), added.clone(), added, removed));
+                    lru.insert(shortstatehash.to_vec(), response.clone());
+                    Ok(response)
+                }
+            }
+
+            fn update_shortstatehash_level(
+                current_shortstatehash: &[u8],
+                statediffnew: HashSet<Vec<u8>>,
+                statediffremoved: HashSet<Vec<u8>>,
+                diff_to_sibling: usize,
+                mut parent_states: Vec<(
+                    Vec<u8>,          // sstatehash
+                    HashSet<Vec<u8>>, // full state
+                    HashSet<Vec<u8>>, // added
+                    HashSet<Vec<u8>>, // removed
+                )>,
+                db: &Database,
+            ) -> Result<()> {
+                let diffsum = statediffnew.len() + statediffremoved.len();
+
+                if parent_states.len() > 3 {
+                    // Number of layers
+                    // To many layers, we have to go deeper
+                    let parent = parent_states.pop().unwrap();
+
+                    let mut parent_new = parent.2;
+                    let mut parent_removed = parent.3;
+
+                    for removed in statediffremoved {
+                        if !parent_new.remove(&removed) {
+                            parent_removed.insert(removed);
+                        }
+                    }
+                    parent_new.extend(statediffnew);
+
+                    update_shortstatehash_level(
+                        current_shortstatehash,
+                        parent_new,
+                        parent_removed,
+                        diffsum,
+                        parent_states,
+                        db,
+                    )?;
+
+                    return Ok(());
+                }
+
+                if parent_states.len() == 0 {
+                    // There is no parent layer, create a new state
+                    let mut value = 0_u64.to_be_bytes().to_vec(); // 0 means no parent
+                    for new in &statediffnew {
+                        value.extend_from_slice(&new);
+                    }
+
+                    if !statediffremoved.is_empty() {
+                        warn!("Tried to create new state with removals");
+                    }
+
+                    db.rooms
+                        .shortstatehash_statediff
+                        .insert(&current_shortstatehash, &value)?;
+
+                    return Ok(());
+                };
+
+                // Else we have two options.
+                // 1. We add the current diff on top of the parent layer.
+                // 2. We replace a layer above
+
+                let parent = parent_states.pop().unwrap();
+                let parent_diff = parent.2.len() + parent.3.len();
+
+                if diffsum * diffsum >= 2 * diff_to_sibling * parent_diff {
+                    // Diff too big, we replace above layer(s)
+                    let mut parent_new = parent.2;
+                    let mut parent_removed = parent.3;
+
+                    for removed in statediffremoved {
+                        if !parent_new.remove(&removed) {
+                            parent_removed.insert(removed);
+                        }
+                    }
+
+                    parent_new.extend(statediffnew);
+                    update_shortstatehash_level(
+                        current_shortstatehash,
+                        parent_new,
+                        parent_removed,
+                        diffsum,
+                        parent_states,
+                        db,
+                    )?;
+                } else {
+                    // Diff small enough, we add diff as layer on top of parent
+                    let mut value = parent.0.clone();
+                    for new in &statediffnew {
+                        value.extend_from_slice(&new);
+                    }
+
+                    if !statediffremoved.is_empty() {
+                        value.extend_from_slice(&0_u64.to_be_bytes());
+                        for removed in &statediffremoved {
+                            value.extend_from_slice(&removed);
+                        }
+                    }
+
+                    db.rooms
+                        .shortstatehash_statediff
+                        .insert(&current_shortstatehash, &value)?;
+                }
+
+                Ok(())
+            }
+
+            if db.globals.database_version()? < 7 {
+                // Upgrade state store
+                let mut lru = LruCache::new(1000);
+                let mut last_roomstates: HashMap<RoomId, Vec<u8>> = HashMap::new();
+                let mut current_sstatehash: Vec<u8> = Vec::new();
+                let mut current_room = None;
+                let mut current_state = HashSet::new();
+                let mut counter = 0;
+                for (k, seventid) in db._db.open_tree("stateid_shorteventid")?.iter() {
+                    let sstatehash = k[0..size_of::<u64>()].to_vec();
+                    let sstatekey = k[size_of::<u64>()..].to_vec();
+                    if sstatehash != current_sstatehash {
+                        if !current_sstatehash.is_empty() {
+                            counter += 1;
+                            println!("counter: {}", counter);
+                            let current_room = current_room.as_ref().unwrap();
+                            let last_roomsstatehash = last_roomstates.get(&current_room);
+
+                            let states_parents = last_roomsstatehash.map_or_else(
+                                || Ok(Vec::new()),
+                                |last_roomsstatehash| {
+                                    load_shortstatehash_info(&last_roomsstatehash, &db, &mut lru)
+                                },
+                            )?;
+
+                            let (statediffnew, statediffremoved) =
+                                if let Some(parent_stateinfo) = states_parents.last() {
+                                    let statediffnew = current_state
+                                        .difference(&parent_stateinfo.1)
+                                        .cloned()
+                                        .collect::<HashSet<_>>();
+
+                                    let statediffremoved = parent_stateinfo
+                                        .1
+                                        .difference(&current_state)
+                                        .cloned()
+                                        .collect::<HashSet<_>>();
+
+                                    (statediffnew, statediffremoved)
+                                } else {
+                                    (current_state, HashSet::new())
+                                };
+
+                            update_shortstatehash_level(
+                                &current_sstatehash,
+                                statediffnew,
+                                statediffremoved,
+                                2, // every state change is 2 event changes on average
+                                states_parents,
+                                &db,
+                            )?;
+
+                            /*
+                            let mut tmp = load_shortstatehash_info(&current_sstatehash, &db)?;
+                            let state = tmp.pop().unwrap();
+                            println!(
+                                "{}\t{}{:?}: {:?} + {:?} - {:?}",
+                                current_room,
+                                "  ".repeat(tmp.len()),
+                                utils::u64_from_bytes(&current_sstatehash).unwrap(),
+                                tmp.last().map(|b| utils::u64_from_bytes(&b.0).unwrap()),
+                                state
+                                    .2
+                                    .iter()
+                                    .map(|b| utils::u64_from_bytes(&b[size_of::<u64>()..]).unwrap())
+                                    .collect::<Vec<_>>(),
+                                state
+                                    .3
+                                    .iter()
+                                    .map(|b| utils::u64_from_bytes(&b[size_of::<u64>()..]).unwrap())
+                                    .collect::<Vec<_>>()
+                            );
+                            */
+
+                            last_roomstates.insert(current_room.clone(), current_sstatehash);
+                        }
+                        current_state = HashSet::new();
+                        current_sstatehash = sstatehash;
+
+                        let event_id = db
+                            .rooms
+                            .shorteventid_eventid
+                            .get(&seventid)
+                            .unwrap()
+                            .unwrap();
+                        let event_id =
+                            EventId::try_from(utils::string_from_bytes(&event_id).unwrap())
+                                .unwrap();
+                        let pdu = db.rooms.get_pdu(&event_id).unwrap().unwrap();
+
+                        if Some(&pdu.room_id) != current_room.as_ref() {
+                            current_room = Some(pdu.room_id.clone());
+                        }
+                    }
+
+                    let mut val = sstatekey;
+                    val.extend_from_slice(&seventid);
+                    current_state.insert(val);
+                }
+
+                db.globals.bump_database_version(7)?;
+
+                println!("Migration: 6 -> 7 finished");
+            }
+
+            if db.globals.database_version()? < 8 {
+                // Generate short room ids for all rooms
+                for (room_id, _) in db.rooms.roomid_shortstatehash.iter() {
+                    let shortroomid = db.globals.next_count()?.to_be_bytes();
+                    db.rooms.roomid_shortroomid.insert(&room_id, &shortroomid)?;
+                    db.rooms.shortroomid_roomid.insert(&shortroomid, &room_id)?;
+                }
+                // Update pduids db layout
+                for (key, v) in db.rooms.pduid_pdu.iter() {
+                    let mut parts = key.splitn(2, |&b| b == 0xff);
+                    let room_id = parts.next().unwrap();
+                    let count = parts.next().unwrap();
+
+                    let short_room_id = db.rooms.roomid_shortroomid.get(&room_id)?.unwrap();
+
+                    let mut new_key = short_room_id;
+                    new_key.extend_from_slice(count);
+
+                    println!("{:?}", new_key);
+                }
+
+                // Update tokenids db layout
+                for (key, _) in db.rooms.tokenids.iter() {
+                    let mut parts = key.splitn(4, |&b| b == 0xff);
+                    let room_id = parts.next().unwrap();
+                    let word = parts.next().unwrap();
+                    let _pdu_id_room = parts.next().unwrap();
+                    let pdu_id_count = parts.next().unwrap();
+
+                    let short_room_id = db.rooms.roomid_shortroomid.get(&room_id)?.unwrap();
+                    let mut new_key = short_room_id;
+                    new_key.extend_from_slice(word);
+                    new_key.push(0xff);
+                    new_key.extend_from_slice(pdu_id_count);
+                    println!("{:?}", new_key);
+                }
+
+                db.globals.bump_database_version(8)?;
+
+                println!("Migration: 7 -> 8 finished");
+            }
+
+            panic!();
         }
 
         let guard = db.read().await;
diff --git a/src/database/abstraction/sqlite.rs b/src/database/abstraction/sqlite.rs
index f420021..f37dd9e 100644
--- a/src/database/abstraction/sqlite.rs
+++ b/src/database/abstraction/sqlite.rs
@@ -223,10 +223,7 @@ impl Tree for SqliteTable {
 
         let statement = Box::leak(Box::new(
             guard
-                .prepare(&format!(
-                    "SELECT key, value FROM {} ORDER BY key ASC",
-                    &self.name
-                ))
+                .prepare(&format!("SELECT key, value FROM {} ORDER BY key ASC", &self.name))
                 .unwrap(),
         ));
 
diff --git a/src/database/rooms.rs b/src/database/rooms.rs
index 88878e9..a3a1c41 100644
--- a/src/database/rooms.rs
+++ b/src/database/rooms.rs
@@ -47,7 +47,7 @@ pub struct Rooms {
     pub(super) aliasid_alias: Arc<dyn Tree>, // AliasId = RoomId + Count
     pub(super) publicroomids: Arc<dyn Tree>,
 
-    pub(super) tokenids: Arc<dyn Tree>, // TokenId = RoomId + Token + PduId
+    pub(super) tokenids: Arc<dyn Tree>, // TokenId = ShortRoomId + Token + PduIdCount
 
     /// Participating servers in a room.
     pub(super) roomserverids: Arc<dyn Tree>, // RoomServerId = RoomId + ServerName
@@ -71,14 +71,18 @@ pub struct Rooms {
     pub(super) shorteventid_shortstatehash: Arc<dyn Tree>,
     /// StateKey = EventType + StateKey, ShortStateKey = Count
     pub(super) statekey_shortstatekey: Arc<dyn Tree>,
+
+    pub(super) shortroomid_roomid: Arc<dyn Tree>,
+    pub(super) roomid_shortroomid: Arc<dyn Tree>,
+
     pub(super) shorteventid_eventid: Arc<dyn Tree>,
-    /// ShortEventId = Count
     pub(super) eventid_shorteventid: Arc<dyn Tree>,
-    /// ShortEventId = Count
+
     pub(super) statehash_shortstatehash: Arc<dyn Tree>,
     /// ShortStateHash = Count
-    /// StateId = ShortStateHash + ShortStateKey
+    /// StateId = ShortStateHash
     pub(super) stateid_shorteventid: Arc<dyn Tree>,
+    pub(super) shortstatehash_statediff: Arc<dyn Tree>, // StateDiff = parent (or 0) + (shortstatekey+shorteventid++) + 0_u64 + (shortstatekey+shorteventid--)
 
     /// RoomId + EventId -> outlier PDU.
     /// Any pdu that has passed the steps 1-8 in the incoming event /federation/send/txn.