diff --git a/server/initialrenderer/job.go b/server/initialrenderer/job.go
index 06dcb57..8c4b3ca 100644
--- a/server/initialrenderer/job.go
+++ b/server/initialrenderer/job.go
@@ -5,7 +5,6 @@ import (
 	"mapserver/coords"
 	"strconv"
 	"time"
-	"runtime"
 	"github.com/sirupsen/logrus"
 )
 
@@ -31,7 +30,6 @@ func Job(ctx *app.App) {
 	}
 
 	fields := logrus.Fields{
-		"jobs": runtime.NumCPU(),
 		"totalLegacyCount": totalLegacyCount,
 	}
 	logrus.WithFields(fields).Info("Starting initial rendering")
@@ -42,9 +40,7 @@ func Job(ctx *app.App) {
 
 	jobs := make(chan *coords.TileCoords, 10)
 
-	for i:=0; i<runtime.NumCPU(); i++ {
-		go worker(ctx, jobs)
-	}
+	go worker(ctx, jobs)
 
 	for true {
 		start := time.Now()
diff --git a/server/mapobjectdb/sqlite_mapobjects.go b/server/mapobjectdb/sqlite_mapobjects.go
index 68a4a04..70b91c7 100644
--- a/server/mapobjectdb/sqlite_mapobjects.go
+++ b/server/mapobjectdb/sqlite_mapobjects.go
@@ -13,8 +13,6 @@ delete from objects where posx = ? and posy = ? and posz = ?
 `
 
 func (db *Sqlite3Accessor) RemoveMapData(pos coords.MapBlockCoords) error {
-	mutex.Lock()
-	defer mutex.Unlock()
 	_, err := db.db.Exec(removeMapDataQuery, pos.X, pos.Y, pos.Z)
 	return err
 }
@@ -32,9 +30,6 @@ values(?, ?, ?)
 `
 
 func (db *Sqlite3Accessor) AddMapData(data MapObject) error {
-	mutex.Lock()
-	defer mutex.Unlock()
-
 	tx, err := db.db.Begin()
 
 	if err != nil {
diff --git a/server/mapobjectdb/sqlite_migrate.go b/server/mapobjectdb/sqlite_migrate.go
index 5b59139..b68a87e 100644
--- a/server/mapobjectdb/sqlite_migrate.go
+++ b/server/mapobjectdb/sqlite_migrate.go
@@ -9,8 +9,8 @@ import (
 
 const migrateScript = `
 PRAGMA foreign_keys = ON;
-PRAGMA journal_mode = MEMORY;
-PRAGMA synchronous = OFF;
+-- PRAGMA journal_mode = MEMORY;
+-- PRAGMA synchronous = OFF;
 
 create table if not exists objects(
 	id integer primary key autoincrement,
diff --git a/server/mapobjectdb/sqlite_tiles.go b/server/mapobjectdb/sqlite_tiles.go
index 88675b4..9533b8e 100644
--- a/server/mapobjectdb/sqlite_tiles.go
+++ b/server/mapobjectdb/sqlite_tiles.go
@@ -4,11 +4,8 @@ import (
 	"database/sql"
 	_ "github.com/mattn/go-sqlite3"
 	"mapserver/coords"
-	"sync"
 )
 
-var mutex = &sync.RWMutex{}
-
 const getTileQuery = `
 select data,mtime from tiles t
 where t.layerid = ?
@@ -57,8 +54,6 @@ values(?, ?, ?, ?, ?, ?)
 `
 
 func (db *Sqlite3Accessor) SetTile(tile *Tile) error {
-	mutex.Lock()
-	defer mutex.Unlock()
 	_, err := db.db.Exec(setTileQuery, tile.Pos.X, tile.Pos.Y, tile.Pos.Zoom, tile.Pos.LayerId, tile.Data, tile.Mtime)
 	return err
 }
@@ -69,8 +64,6 @@ where x = ? and y = ? and zoom = ? and layerid = ?
 `
 
 func (db *Sqlite3Accessor) RemoveTile(pos *coords.TileCoords) error {
-	mutex.Lock()
-	defer mutex.Unlock()
 	_, err := db.db.Exec(removeTileQuery, pos.X, pos.Y, pos.Zoom, pos.LayerId)
 	return err
 }