diff --git a/Database/Groundhog/Postgresql.hs b/Database/Groundhog/Postgresql.hs
--- a/Database/Groundhog/Postgresql.hs
+++ b/Database/Groundhog/Postgresql.hs
@@ -2,6 +2,7 @@
 module Database.Groundhog.Postgresql
     ( withPostgresqlPool
     , withPostgresqlConn
+    , createPostgresqlPool
     , runDbConn
     , Postgresql(..)
     , module Database.Groundhog
@@ -59,13 +60,13 @@
   type PhantomDb (DbPersist Postgresql m) = Postgresql
   insert v = insert' v
   insert_ v = insert_' v
-  insertBy u v = H.insertBy escapeS queryRawTyped' u v
-  insertByAll v = H.insertByAll escapeS queryRawTyped' v
+  insertBy u v = H.insertBy escapeS queryRawTyped' " IS NOT DISTINCT FROM ?" u v
+  insertByAll v = H.insertByAll escapeS queryRawTyped' " IS NOT DISTINCT FROM ?" v
   replace k v = H.replace escapeS queryRawTyped' executeRaw' (insertIntoConstructorTable False) k v
   select options = H.select escapeS queryRawTyped' "" renderCond' options
   selectAll = H.selectAll escapeS queryRawTyped'
   get k = H.get escapeS queryRawTyped' k
-  getBy k = H.getBy escapeS queryRawTyped' k
+  getBy k = H.getBy escapeS queryRawTyped' " IS NOT DISTINCT FROM ?" k
   update upds cond = H.update escapeS executeRaw' renderCond' upds cond
   delete cond = H.delete escapeS executeRaw' renderCond' cond
   deleteByKey k = H.deleteByKey escapeS executeRaw' k
@@ -95,21 +96,25 @@
       Nothing  -> return Nothing
       Just src -> return (fst $ fromPurePersistValues proxy src)
 
---{-# SPECIALIZE withPostgresqlPool :: String -> Int -> (Pool Postgresql -> IO a) -> IO a #-}
 withPostgresqlPool :: (MonadBaseControl IO m, MonadIO m)
-               => String -- ^ connection string
-               -> Int -- ^ number of connections to open
-               -> (Pool Postgresql -> m a)
-               -> m a
-withPostgresqlPool s connCount f = liftIO (createPool (open' s) close' 1 20 connCount) >>= f
+                   => String -- ^ connection string
+                   -> Int -- ^ number of connections to open
+                   -> (Pool Postgresql -> m a)
+                   -> m a
+withPostgresqlPool s connCount f = createPostgresqlPool s connCount >>= f
 
-{-# SPECIALIZE withPostgresqlConn :: String -> (Postgresql -> IO a) -> IO a #-}
 withPostgresqlConn :: (MonadBaseControl IO m, MonadIO m)
-               => String -- ^ connection string
-               -> (Postgresql -> m a)
-               -> m a
+                   => String -- ^ connection string
+                   -> (Postgresql -> m a)
+                   -> m a
 withPostgresqlConn s = bracket (liftIO $ open' s) (liftIO . close')
 
+createPostgresqlPool :: MonadIO m
+                     => String -- ^ connection string
+                     -> Int -- ^ number of connections to open
+                     -> m (Pool Postgresql)
+createPostgresqlPool s connCount = liftIO $ createPool (open' s) close' 1 20 connCount
+
 instance Savepoint Postgresql where
   withConnSavepoint name m (Postgresql c) = do
     let name' = fromString name
@@ -269,7 +274,7 @@
   migTriggerOnUpdate
   GM.defaultMigConstr
   escape
-  "SERIAL PRIMARY KEY UNIQUE"
+  "BIGSERIAL PRIMARY KEY UNIQUE"
   mainTableId
   defaultPriority
   (\uniques refs -> ([], map AddUnique uniques ++ map AddReference refs))
diff --git a/groundhog-postgresql.cabal b/groundhog-postgresql.cabal
--- a/groundhog-postgresql.cabal
+++ b/groundhog-postgresql.cabal
@@ -1,5 +1,5 @@
 name:            groundhog-postgresql
-version:         0.4.0.1
+version:         0.4.0.2
 license:         BSD3
 license-file:    LICENSE
 author:          Boris Lykah <lykahb@gmail.com>
@@ -7,7 +7,7 @@
 synopsis:        PostgreSQL backend for the groundhog library.
 description:     This package uses postgresql-simple and postgresql-libpq.
 category:        Database
-stability:       Non-stable
+stability:       Stable
 cabal-version:   >= 1.6
 build-type:      Simple
 
@@ -18,7 +18,7 @@
                    , bytestring              >= 0.9
                    , blaze-builder           >= 0.3.0.0
                    , transformers            >= 0.2.1
-                   , groundhog               >= 0.4.0     && < 0.5.0
+                   , groundhog               >= 0.4.0.2   && < 0.5.0
                    , monad-control           >= 0.3
                    , monad-logger            >= 0.3
                    , containers              >= 0.2