diff --git a/hasql-postgres.cabal b/hasql-postgres.cabal
--- a/hasql-postgres.cabal
+++ b/hasql-postgres.cabal
@@ -1,7 +1,7 @@
 name:
   hasql-postgres
 version:
-  0.1.0
+  0.1.1
 synopsis:
   A "PostgreSQL" driver for the "hasql" library
 description:
@@ -69,7 +69,6 @@
     old-locale == 1.0.*,
     time == 1.4.*,
     hashtables == 1.1.*,
-    Decimal == 0.4.*,
     scientific == 0.3.*,
     text >= 1 && < 1.3,
     bytestring >= 0.10.4.0 && < 0.11,
diff --git a/library/Hasql/Postgres.hs b/library/Hasql/Postgres.hs
--- a/library/Hasql/Postgres.hs
+++ b/library/Hasql/Postgres.hs
@@ -1,4 +1,8 @@
-module Hasql.Postgres (Postgres(..)) where
+module Hasql.Postgres 
+(
+  Postgres(..), 
+)
+where
 
 import Hasql.Postgres.Prelude
 import qualified Database.PostgreSQL.LibPQ as PQ
@@ -138,6 +142,8 @@
 -- * Mappings
 -------------------------
 
+-- | Maps to the same type as the underlying value, 
+-- encoding the 'Nothing' as /NULL/.
 instance Backend.Mapping Postgres a => Backend.Mapping Postgres (Maybe a) where
   renderValue =
     \case
@@ -148,85 +154,133 @@
         Backend.renderValue v
   parseResult = traverse (Backend.parseResult . Result . Just) . unpackResult
 
+-- | Maps to \"bool\".
 instance Backend.Mapping Postgres Bool where
-  renderValue = mkRenderValue OID.bool Renderer.bool
+  renderValue = mkRenderValue PQ.Text OID.bool Renderer.bool
   parseResult = mkParseResult Parser.bool
 
-instance Backend.Mapping Postgres Char where
-  renderValue = mkRenderValue OID.varchar Renderer.char
-  parseResult = mkParseResult Parser.utf8Char
-
-instance Backend.Mapping Postgres Text where
-  renderValue = mkRenderValue OID.text Renderer.text
-  parseResult = mkParseResult Parser.utf8Text
-
+-- | Maps to \"int8\".
 instance Backend.Mapping Postgres Int where
-  renderValue = mkRenderValue OID.int8 Renderer.int
+  renderValue = mkRenderValue PQ.Text OID.int8 Renderer.int
   parseResult = mkParseResult Parser.integral
 
+-- | Maps to \"int2\".
 instance Backend.Mapping Postgres Int8 where
-  renderValue = mkRenderValue OID.int2 Renderer.int8
+  renderValue = mkRenderValue PQ.Text OID.int2 Renderer.int8
   parseResult = mkParseResult Parser.integral
 
+-- | Maps to \"int2\".
 instance Backend.Mapping Postgres Int16 where
-  renderValue = mkRenderValue OID.int2 Renderer.int16
+  renderValue = mkRenderValue PQ.Text OID.int2 Renderer.int16
   parseResult = mkParseResult Parser.integral
 
+-- | Maps to \"int4\".
 instance Backend.Mapping Postgres Int32 where
-  renderValue = mkRenderValue OID.int4 Renderer.int32
+  renderValue = mkRenderValue PQ.Text OID.int4 Renderer.int32
   parseResult = mkParseResult Parser.integral
 
+-- | Maps to \"int8\".
 instance Backend.Mapping Postgres Int64 where
-  renderValue = mkRenderValue OID.int8 Renderer.int64
+  renderValue = mkRenderValue PQ.Text OID.int8 Renderer.int64
   parseResult = mkParseResult Parser.integral
 
+-- | Maps to \"int8\".
 instance Backend.Mapping Postgres Word where
-  renderValue = mkRenderValue OID.int8 Renderer.word
+  renderValue = mkRenderValue PQ.Text OID.int8 Renderer.word
   parseResult = mkParseResult Parser.unsignedIntegral
 
+-- | Maps to \"int2\".
 instance Backend.Mapping Postgres Word8 where
-  renderValue = mkRenderValue OID.int2 Renderer.word8
+  renderValue = mkRenderValue PQ.Text OID.int2 Renderer.word8
   parseResult = mkParseResult Parser.unsignedIntegral
 
+-- | Maps to \"int4\".
 instance Backend.Mapping Postgres Word16 where
-  renderValue = mkRenderValue OID.int4 Renderer.word16
+  renderValue = mkRenderValue PQ.Text OID.int4 Renderer.word16
   parseResult = mkParseResult Parser.unsignedIntegral
 
+-- | Maps to \"int8\".
 instance Backend.Mapping Postgres Word32 where
-  renderValue = mkRenderValue OID.int8 Renderer.word32
+  renderValue = mkRenderValue PQ.Text OID.int8 Renderer.word32
   parseResult = mkParseResult Parser.unsignedIntegral
 
+-- | Maps to \"int8\".
 instance Backend.Mapping Postgres Word64 where
-  renderValue = mkRenderValue OID.int8 Renderer.word64
+  renderValue = mkRenderValue PQ.Text OID.int8 Renderer.word64
   parseResult = mkParseResult Parser.unsignedIntegral
 
+-- | Maps to \"float4\".
+instance Backend.Mapping Postgres Float where
+  renderValue = mkRenderValue PQ.Text OID.float4 Renderer.float
+  parseResult = mkParseResult Parser.float
+
+-- | Maps to \"float8\".
+instance Backend.Mapping Postgres Double where
+  renderValue = mkRenderValue PQ.Text OID.float8 Renderer.double
+  parseResult = mkParseResult Parser.double
+
+-- | Maps to \"numeric\".
+instance Backend.Mapping Postgres Scientific where
+  renderValue = mkRenderValue PQ.Text OID.numeric Renderer.scientific
+  parseResult = mkParseResult Parser.scientific
+
+-- | Maps to \"date\".
 instance Backend.Mapping Postgres Day where
-  renderValue = mkRenderValue OID.date Renderer.day
+  renderValue = mkRenderValue PQ.Text OID.date Renderer.day
   parseResult = mkParseResult Parser.day
 
+-- | Maps to \"time\".
 instance Backend.Mapping Postgres TimeOfDay where
-  renderValue = mkRenderValue OID.time Renderer.timeOfDay
+  renderValue = mkRenderValue PQ.Text OID.time Renderer.timeOfDay
   parseResult = mkParseResult Parser.timeOfDay
 
+-- | Maps to \"timestamp\".
 instance Backend.Mapping Postgres LocalTime where
-  renderValue = mkRenderValue OID.timestamp Renderer.localTime
+  renderValue = mkRenderValue PQ.Text OID.timestamp Renderer.localTime
   parseResult = mkParseResult Parser.localTime
 
+-- | Maps to \"timestamptz\".
 instance Backend.Mapping Postgres ZonedTime where
-  renderValue = mkRenderValue OID.timestamptz Renderer.zonedTime 
+  renderValue = mkRenderValue PQ.Text OID.timestamptz Renderer.zonedTime 
   parseResult = mkParseResult Parser.zonedTime 
 
+-- | Maps to \"timestamp\".
 instance Backend.Mapping Postgres UTCTime where
-  renderValue = mkRenderValue OID.timestamp Renderer.utcTime
+  renderValue = mkRenderValue PQ.Text OID.timestamp Renderer.utcTime
   parseResult = mkParseResult Parser.utcTime
 
+-- | Maps to \"varchar\".
+instance Backend.Mapping Postgres Char where
+  renderValue = mkRenderValue PQ.Text OID.varchar Renderer.char
+  parseResult = mkParseResult Parser.utf8Char
 
+-- | Maps to \"text\".
+instance Backend.Mapping Postgres Text where
+  renderValue = mkRenderValue PQ.Text OID.text Renderer.text
+  parseResult = mkParseResult Parser.utf8Text
+
+-- | Maps to \"text\".
+instance Backend.Mapping Postgres LazyText where
+  renderValue = mkRenderValue PQ.Text OID.text Renderer.lazyText
+  parseResult = mkParseResult Parser.utf8LazyText
+
+-- | Maps to \"bytea\".
+instance Backend.Mapping Postgres ByteString where
+  renderValue = mkRenderValue PQ.Binary OID.bytea Renderer.byteString
+  parseResult = mkParseResult Parser.byteString
+
+-- | Maps to \"bytea\".
+instance Backend.Mapping Postgres LazyByteString where
+  renderValue = mkRenderValue PQ.Binary OID.bytea Renderer.lazyByteString
+  parseResult = mkParseResult Parser.lazyByteString
+
+
 -- |
--- Make a 'renderValue' function with the 'Text' format.
+-- Make a 'renderValue' function.
 {-# INLINE mkRenderValue #-}
-mkRenderValue :: PQ.Oid -> Renderer.R a -> (a -> Backend.StatementArgument Postgres)
-mkRenderValue o r a =
-  StatementArgument (o, Just (Renderer.run a r, PQ.Text))
+mkRenderValue :: PQ.Format -> PQ.Oid -> Renderer.R a -> (a -> Backend.StatementArgument Postgres)
+mkRenderValue f o r a =
+  StatementArgument (o, Just (Renderer.run a r, f))
 
 {-# INLINE mkParseResult #-}
 mkParseResult :: Parser.P a -> (Backend.Result Postgres -> Either Text a)
diff --git a/library/Hasql/Postgres/Connector.hs b/library/Hasql/Postgres/Connector.hs
--- a/library/Hasql/Postgres/Connector.hs
+++ b/library/Hasql/Postgres/Connector.hs
@@ -49,7 +49,8 @@
       [ "SET standard_conforming_strings TO on",
         "SET datestyle TO ISO",
         "SET client_encoding = 'UTF8'",
-        "SET client_min_messages TO WARNING" ]
+        "SET client_min_messages TO WARNING",
+        "SET bytea_output = 'hex'" ]
     return c
 
 
diff --git a/library/Hasql/Postgres/OID.hs b/library/Hasql/Postgres/OID.hs
--- a/library/Hasql/Postgres/OID.hs
+++ b/library/Hasql/Postgres/OID.hs
@@ -5,50 +5,54 @@
 
 type OID = Oid
 
-abstime     = Oid 702
-bit         = Oid 1560
-bool        = Oid 16
-box         = Oid 603
-bpchar      = Oid 1042
-bytea       = Oid 17
-char        = Oid 18
-cid         = Oid 29
-cidr        = Oid 650
-circle      = Oid 718
-date        = Oid 1082
-float4      = Oid 700
-float8      = Oid 701
-inet        = Oid 869
-int2        = Oid 21
-int4        = Oid 23
-int8        = Oid 20
-interval    = Oid 1186
-json        = Oid 114
-line        = Oid 628
-lseg        = Oid 601
-macaddr     = Oid 829
-money       = Oid 790
-name        = Oid 19
-numeric     = Oid 1700
-oid         = Oid 26
-path        = Oid 602
-point       = Oid 600
-polygon     = Oid 604
-record      = Oid 2249
-refcursor   = Oid 1790
-regproc     = Oid 24
-reltime     = Oid 703
-text        = Oid 25
-tid         = Oid 27
-time        = Oid 1083
-timestamp   = Oid 1114
-timestamptz = Oid 1184
-timetz      = Oid 1266
-tinterval   = Oid 704
-unknown     = Oid 705
-uuid        = Oid 2950
-varbit      = Oid 1562
-varchar     = Oid 1043
-void        = Oid 2278
-xid         = Oid 28
-xml         = Oid 142
+abstime     :: OID = Oid 702
+anyarray    :: OID = Oid 2277
+bit         :: OID = Oid 1560
+bool        :: OID = Oid 16
+box         :: OID = Oid 603
+bpchar      :: OID = Oid 1042
+bytea       :: OID = Oid 17
+char        :: OID = Oid 18
+cid         :: OID = Oid 29
+cidr        :: OID = Oid 650
+circle      :: OID = Oid 718
+date        :: OID = Oid 1082
+float4      :: OID = Oid 700
+float8      :: OID = Oid 701
+gtsvector   :: OID = Oid 3642
+inet        :: OID = Oid 869
+int2        :: OID = Oid 21
+int2vector  :: OID = Oid 22
+int4        :: OID = Oid 23
+int8        :: OID = Oid 20
+interval    :: OID = Oid 1186
+json        :: OID = Oid 114
+line        :: OID = Oid 628
+lseg        :: OID = Oid 601
+macaddr     :: OID = Oid 829
+money       :: OID = Oid 790
+name        :: OID = Oid 19
+numeric     :: OID = Oid 1700
+oid         :: OID = Oid 26
+path        :: OID = Oid 602
+point       :: OID = Oid 600
+polygon     :: OID = Oid 604
+record      :: OID = Oid 2249
+refcursor   :: OID = Oid 1790
+regproc     :: OID = Oid 24
+reltime     :: OID = Oid 703
+text        :: OID = Oid 25
+tid         :: OID = Oid 27
+time        :: OID = Oid 1083
+timestamp   :: OID = Oid 1114
+timestamptz :: OID = Oid 1184
+timetz      :: OID = Oid 1266
+tinterval   :: OID = Oid 704
+tsvector    :: OID = Oid 3614
+unknown     :: OID = Oid 705
+uuid        :: OID = Oid 2950
+varbit      :: OID = Oid 1562
+varchar     :: OID = Oid 1043
+void        :: OID = Oid 2278
+xid         :: OID = Oid 28
+xml         :: OID = Oid 142
diff --git a/library/Hasql/Postgres/Parser.hs b/library/Hasql/Postgres/Parser.hs
--- a/library/Hasql/Postgres/Parser.hs
+++ b/library/Hasql/Postgres/Parser.hs
@@ -2,12 +2,15 @@
 
 import Hasql.Postgres.Prelude hiding (take)
 import Data.Attoparsec.ByteString
-import Data.Attoparsec.ByteString.Char8
+import Data.Attoparsec.ByteString.Char8 hiding (double)
 import qualified Data.ByteString
+import qualified Data.ByteString.Lazy
 import qualified Data.Text
 import qualified Data.Text.Encoding
 import qualified Data.Text.Lazy
 import qualified Data.Text.Lazy.Encoding
+import qualified Data.Attoparsec.ByteString.Char8 as A
+import qualified Database.PostgreSQL.LibPQ as PQ
 
 
 type P = Parser
@@ -20,15 +23,38 @@
 -- ** Parser
 -------------------------
 
+{-# INLINE labeling #-}
 labeling :: String -> Parser a -> Parser a
 labeling n p = 
   p <?> n
 
+scientific :: P Scientific
+scientific =
+  A.scientific
+
+float :: P Float
+float =
+  realToFrac <$> double
+
+double :: P Double
+double = 
+  labeling "double" $ A.double
+
 bool :: P Bool
 bool =
   labeling "bool" $
     ((string "true" <|> string "t" <|> string "True" <|> string "1") *> pure True) <|>
     ((string "false" <|> string "f" <|> string "False" <|> string "0") *> pure False)
+
+byteString :: P ByteString
+byteString =
+  labeling "byteString" $
+    takeByteString >>= maybe (fail "Improper encoding") return . unsafePerformIO . PQ.unescapeBytea
+
+lazyByteString :: P LazyByteString
+lazyByteString =
+  labeling "lazyByteString" $
+    Data.ByteString.Lazy.fromStrict <$> byteString
 
 utf8Char :: P Char
 utf8Char =
diff --git a/library/Hasql/Postgres/Prelude.hs b/library/Hasql/Postgres/Prelude.hs
--- a/library/Hasql/Postgres/Prelude.hs
+++ b/library/Hasql/Postgres/Prelude.hs
@@ -1,6 +1,8 @@
 module Hasql.Postgres.Prelude
 ( 
   module Exports,
+  LazyByteString,
+  LazyText,
   bug,
   bottom,
   partial,
@@ -36,10 +38,6 @@
 -------------------------
 import Data.ByteString as Exports (ByteString)
 
--- decimal
--------------------------
-import Data.Decimal as Exports (Decimal, DecimalRaw)
-
 -- scientific
 -------------------------
 import Data.Scientific as Exports (Scientific)
@@ -63,7 +61,12 @@
 -- custom
 -------------------------
 import qualified Debug.Trace.LocationTH
+import qualified Data.Text.Lazy
+import qualified Data.ByteString.Lazy
 
+
+type LazyByteString = Data.ByteString.Lazy.ByteString
+type LazyText = Data.Text.Lazy.Text
 
 bug = [e| $(Debug.Trace.LocationTH.failure) . (msg <>) |]
   where
diff --git a/library/Hasql/Postgres/Renderer.hs b/library/Hasql/Postgres/Renderer.hs
--- a/library/Hasql/Postgres/Renderer.hs
+++ b/library/Hasql/Postgres/Renderer.hs
@@ -7,6 +7,7 @@
 import qualified Data.ByteString.Builder as B
 import qualified Data.ByteString.Lazy as L
 import qualified Data.Text.Encoding as T
+import qualified Data.Text.Lazy.Encoding as LT
 import qualified Data.ByteString.Builder.Scientific
 
 
@@ -45,10 +46,16 @@
 byteString :: R ByteString = 
   B.byteString
 
+lazyByteString :: R LazyByteString = 
+  B.lazyByteString
+
 text :: R Text =
   byteString . T.encodeUtf8
 
+lazyText :: R LazyText =
+  lazyByteString . LT.encodeUtf8
 
+
 -- *** enumerations
 -------------------------
 
@@ -105,21 +112,6 @@
   
 double :: R Double =
   B.doubleDec
-
-decimalRawInt32 :: R (DecimalRaw Int32) =
-  ascii
-
-decimalRawInt64 :: R (DecimalRaw Int64) =
-  ascii
-
-decimalRawWord32 :: R (DecimalRaw Word32) =
-  ascii
-
-decimalRawWord64 :: R (DecimalRaw Word64) =
-  ascii
-
-decimal :: R Decimal =
-  ascii
 
 pico :: R Pico =
   B.string7 . showFixed True
diff --git a/tests/Main.hs b/tests/Main.hs
--- a/tests/Main.hs
+++ b/tests/Main.hs
@@ -7,17 +7,28 @@
 import Test.QuickCheck.Instances
 import Hasql
 import Hasql.Postgres (Postgres(..))
-import Data.Text (Text)
 import Data.Time
 import qualified Data.Text
+import qualified Data.Text.Lazy
+import qualified Data.ByteString
+import qualified Data.ByteString.Char8
+import qualified Data.ByteString.Lazy
+import qualified Data.ByteString.Lazy.Char8
 import qualified ListT
 import qualified SlaveThread
 import qualified Control.Concurrent.SSem as SSem
 import qualified Hasql.Backend as Backend
 import qualified Hasql as H
 import qualified Hasql.Postgres as H
+import qualified Data.Scientific as Scientific
 
 
+type Text = Data.Text.Text
+type LazyText = Data.Text.Lazy.Text
+type ByteString = Data.ByteString.ByteString
+type LazyByteString = Data.ByteString.Lazy.ByteString
+type Scientific = Scientific.Scientific
+
 main = 
   htfMain $ htf_thisModulesTests
 
@@ -39,7 +50,14 @@
     rows = [("A", 34525), ("B", 324987)] :: [(Text, Int)]
 
 test_countEffects =
-  unitTestPending ""
+  assertEqual 100 =<< do 
+    session1 $ do
+      tx Nothing $ do
+        unit [q|DROP TABLE IF EXISTS a|]
+        unit [q|CREATE TABLE a (id SERIAL NOT NULL, name VARCHAR NOT NULL)|]
+        replicateM_ 100 $ do
+          unit [q|INSERT INTO a (name) VALUES ('a')|]
+        count [q|DELETE FROM a|]
 
 test_autoIncrement =
   assertEqual (Just (1 :: Word64), Just (2 :: Word64)) =<< do
@@ -122,6 +140,16 @@
   (isNothing $ Data.Text.find (== '\NUL') v) ==>
     Just v === do unsafePerformIO $ session1 $ selectSelf v
 
+prop_mappingOfLazyText (v :: LazyText) =
+  (isNothing $ Data.Text.Lazy.find (== '\NUL') v) ==>
+    Just v === do unsafePerformIO $ session1 $ selectSelf v
+
+prop_mappingOfByteString (v :: ByteString) =
+  Just v === do unsafePerformIO $ session1 $ selectSelf v
+
+prop_mappingOfLazyByteString (v :: LazyByteString) =
+  Just v === do unsafePerformIO $ session1 $ selectSelf v
+
 prop_mappingOfInt (v :: Int) =
   Just v === do unsafePerformIO $ session1 $ selectSelf v
 
@@ -152,6 +180,16 @@
 prop_mappingOfWord64 (v :: Word64) =
   Just v === do unsafePerformIO $ session1 $ selectSelf v
 
+prop_mappingOfFloat (v :: Float) =
+  floatEq v (fromJust $ unsafePerformIO $ session1 $ selectSelf v)
+
+prop_mappingOfDouble (v :: Double) =
+  floatEq v (fromJust $ unsafePerformIO $ session1 $ selectSelf v)
+
+prop_mappingOfScientific =
+  forAll scientificGen $ \v ->
+    Just v === do unsafePerformIO $ session1 $ selectSelf v
+
 prop_mappingOfDay (v :: Day) =
   Just v === do unsafePerformIO $ session1 $ selectSelf v
 
@@ -180,6 +218,10 @@
   where
     gen = UTCTime <$> arbitrary <*> microsDiffTimeGen
 
+scientificGen :: Gen Scientific
+scientificGen =
+  Scientific.scientific <$> arbitrary <*> arbitrary
+
 microsTimeOfDayGen :: Gen TimeOfDay
 microsTimeOfDayGen =
   timeToTimeOfDay <$> microsDiffTimeGen
@@ -210,3 +252,10 @@
   where
     backendSettings = Postgres "localhost" 5432 "postgres" "" "postgres"
     poolSettings = fromJust $ sessionSettings 6 30
+
+floatEq :: RealFrac a => Show a => a -> a -> Property
+floatEq a b =
+  counterexample (show a ++ " /~ " ++ show b) $
+    a + error >= b && a - error <= b
+  where
+    error = max (abs a) 1 / 100