diff --git a/DSH.cabal b/DSH.cabal
--- a/DSH.cabal
+++ b/DSH.cabal
@@ -1,5 +1,5 @@
 Name:                DSH
-Version:             0.6.1
+Version:             0.6.2
 Synopsis:            Database Supported Haskell
 Description:
   This is a Haskell library for database-supported program execution. Using
diff --git a/examples/Example2.hs b/examples/Example2.hs
--- a/examples/Example2.hs
+++ b/examples/Example2.hs
@@ -21,14 +21,14 @@
   ]
 
 query :: Q [(Text, Integer)]
-query = [$qc| tuple (the dept, sum salary)
-            | (name, dept, salary) <- employees
-            , then group by dept
-            , then sortWith by (sum salary)
-            , then take 5 |]
+query = [qc| tuple (the dept, sum salary)
+           | (name, dept, salary) <- employees
+          , then group by dept
+          , then sortWith by (sum salary)
+          , then take 5 |]
 
 getConn :: IO Connection
-getConn = connectPostgreSQL "user = 'postgres' password = 'haskell98' host = 'localhost' dbname = 'ferry'"
+getConn = connectPostgreSQL "user = 'giorgidz' password = '' host = 'localhost' dbname = 'giorgidz'"
 
 main :: IO ()
 main = do
diff --git a/src/Database/DSH/Combinators.hs b/src/Database/DSH/Combinators.hs
--- a/src/Database/DSH/Combinators.hs
+++ b/src/Database/DSH/Combinators.hs
@@ -336,9 +336,9 @@
 
 -- 'QA', 'TA' and 'View' instances for tuples up to the defined length.
 
-$(generateDeriveTupleQARange   3 12)
-$(generateDeriveTupleTARange   3 12)
-$(generateDeriveTupleViewRange 3 12)
+$(generateDeriveTupleQARange   3 16)
+$(generateDeriveTupleTARange   3 16)
+$(generateDeriveTupleViewRange 3 16)
 
 
 -- * Missing Combinators
diff --git a/src/Database/DSH/Compile.hs b/src/Database/DSH/Compile.hs
--- a/src/Database/DSH/Compile.hs
+++ b/src/Database/DSH/Compile.hs
@@ -13,25 +13,12 @@
 import Control.Monad.Reader
 import Control.Exception (evaluate)
 
-import Control.Concurrent.MVar
-import System.IO.Unsafe (unsafePerformIO)
-
 import qualified Text.XML.HaXml as X
 import Text.XML.HaXml (Content(..), AttValue(..), tag, deep, children, xmlParse, Document(..))
 
 import Database.HDBC
 import Data.Convertible
 
-
--- | This is a global synchronisation variable used to gouard calls to the
--- Pathfinder C library. The C library appears not to be thread safe and this
--- variable is used to make sure that only one pathfinder call is made at time
--- even when a number parallel calls are made to the DSH's fromQ query
--- evaluator.
-{-# NOINLINE globalMVar #-}
-globalMVar :: MVar ()
-globalMVar = unsafePerformIO (newEmptyMVar)
-
 -- | Wrapper type with phantom type for algebraic plan
 -- The type variable represents the type of the result of the plan
 newtype AlgebraXML a = Algebra String
@@ -67,27 +54,21 @@
                         runSQL c $ extractSQL sql
 
 algToAlg :: AlgebraXML a -> IO (AlgebraXML a)
-algToAlg (Algebra s) = do
-                        putMVar  globalMVar ()
-                        r <- pathfinder s [] OutputXml
-                        takeMVar globalMVar
-                        case r of
-                           (Right sql) -> return $ Algebra sql
-                           (Left err) -> error $ "Pathfinder compilation for input: \n"
-                                                   ++ s ++ "\n failed with error: \n"
-                                                   ++ err
+algToAlg (Algebra s) = do r <- pathfinder s [] OutputXml
+                          case r of
+                            (Right sql) -> return $ Algebra sql
+                            (Left err)  -> error $ "Pathfinder compilation for input: \n"
+                                                     ++ s ++ "\n failed with error: \n"
+                                                     ++ err
 
 -- | Translate an algebraic plan into SQL code using Pathfinder
 algToSQL :: AlgebraXML a -> IO (SQLXML a)
-algToSQL (Algebra s) = do
-                         putMVar  globalMVar ()
-                         r <- pathfinder s [] OutputSql
-                         takeMVar globalMVar
-                         case r of
-                            (Right sql) -> return $ SQL sql
-                            (Left err) -> error $ "Pathfinder compilation for input: \n"
-                                                    ++ s ++ "\n failed with error: \n"
-                                                    ++ err
+algToSQL (Algebra s) = do r <- pathfinder s [] OutputSql
+                          case r of
+                             (Right sql) -> return $ SQL sql
+                             (Left err) -> error $ "Pathfinder compilation for input: \n"
+                                                     ++ s ++ "\n failed with error: \n"
+                                                     ++ err
 
 -- | Extract the SQL queries from the XML structure generated by pathfinder
 extractSQL :: SQLXML a -> QueryBundle a