diff --git a/ChangeLog.md b/ChangeLog.md
--- a/ChangeLog.md
+++ b/ChangeLog.md
@@ -1,5 +1,10 @@
 <!-- -*- Markdown -*- -->
 
+## 0.1.8.0
+
+- update for GHC 8.8.x.
+- allow more type-categories of PostgreSQL.
+
 ## 0.1.7.0
 
 - adjust sub-directory modules of each DBMS to top module name.
diff --git a/relational-schemas.cabal b/relational-schemas.cabal
--- a/relational-schemas.cabal
+++ b/relational-schemas.cabal
@@ -1,5 +1,5 @@
 name:                relational-schemas
-version:             0.1.7.0
+version:             0.1.8.0
 synopsis:            RDBMSs' schema templates for relational-query
 description:         This package contains some RDBMSs' schema structure definitions.
                      .
@@ -20,7 +20,8 @@
 category:            Database
 build-type:          Simple
 cabal-version:       >=1.10
-tested-with:           GHC == 8.6.1, GHC == 8.6.2, GHC == 8.6.3, GHC == 8.6.4, GHC == 8.6.5
+tested-with:           GHC == 8.8.1, GHC == 8.8.2
+                     , GHC == 8.6.1, GHC == 8.6.2, GHC == 8.6.3, GHC == 8.6.4, GHC == 8.6.5
                      , GHC == 8.4.1, GHC == 8.4.2, GHC == 8.4.3, GHC == 8.4.4
                      , GHC == 8.2.1, GHC == 8.2.2
                      , GHC == 8.0.1, GHC == 8.0.2
@@ -108,6 +109,7 @@
                        , time
                        , bytestring
 
+                       , sql-words
                        , relational-query >= 0.12.2
 
   if impl(ghc == 7.4.*)
@@ -116,7 +118,9 @@
   hs-source-dirs:      src
   ghc-options:         -Wall
   if impl(ghc >= 8)
-    ghc-options:         -Wcompat -Wnoncanonical-monadfail-instances
+    ghc-options:         -Wcompat
+  if impl(ghc >= 8) && impl(ghc < 8.8)
+    ghc-options:         -Wnoncanonical-monadfail-instances
 
   default-language:    Haskell2010
 
diff --git a/src/Database/Custom/IBMDB2.hs b/src/Database/Custom/IBMDB2.hs
--- a/src/Database/Custom/IBMDB2.hs
+++ b/src/Database/Custom/IBMDB2.hs
@@ -19,6 +19,7 @@
   delete, deleteNoPH,
   ) where
 
+import Language.SQL.Keyword (Keyword)
 import Database.Relational.Schema.IBMDB2.Config (config)
 import Database.Relational hiding
   (relationalQuery,
@@ -27,7 +28,9 @@
    delete, deleteNoPH, )
 
 -- | From 'Relation' into typed 'Query' with suffix SQL words.
-relationalQuery :: Relation p r -> QuerySuffix -> Query p r
+relationalQuery :: Relation p r  -- ^ relation to finalize building
+                -> [Keyword]     -- ^ suffix SQL words. for example, `[FOR, UPDATE]`, `[FETCH, FIRST, "3", ROWS, ONLY]` ...
+                -> Query p r     -- ^ finalized query
 relationalQuery = relationalQuery_ config
 
 -- | Make 'Insert' from derived table and monadic builded 'Register' object.
diff --git a/src/Database/Custom/MySQL.hs b/src/Database/Custom/MySQL.hs
--- a/src/Database/Custom/MySQL.hs
+++ b/src/Database/Custom/MySQL.hs
@@ -19,6 +19,7 @@
   delete, deleteNoPH,
   ) where
 
+import Language.SQL.Keyword (Keyword)
 import Database.Relational.Schema.MySQL.Config (config)
 import Database.Relational hiding
   (relationalQuery,
@@ -27,7 +28,9 @@
    delete, deleteNoPH, )
 
 -- | From 'Relation' into typed 'Query' with suffix SQL words.
-relationalQuery :: Relation p r -> QuerySuffix -> Query p r
+relationalQuery :: Relation p r  -- ^ relation to finalize building
+                -> [Keyword]     -- ^ suffix SQL words. for example, `[FOR, UPDATE]`, `[FETCH, FIRST, "3", ROWS, ONLY]` ...
+                -> Query p r     -- ^ finalized query
 relationalQuery = relationalQuery_ config
 
 -- | Make 'Insert' from derived table and monadic builded 'Register' object.
diff --git a/src/Database/Custom/Oracle.hs b/src/Database/Custom/Oracle.hs
--- a/src/Database/Custom/Oracle.hs
+++ b/src/Database/Custom/Oracle.hs
@@ -19,6 +19,7 @@
   delete, deleteNoPH,
   ) where
 
+import Language.SQL.Keyword (Keyword)
 import Database.Relational.Schema.Oracle.Config (config)
 import Database.Relational hiding
   (relationalQuery,
@@ -27,7 +28,9 @@
    delete, deleteNoPH, )
 
 -- | From 'Relation' into typed 'Query' with suffix SQL words.
-relationalQuery :: Relation p r -> QuerySuffix -> Query p r
+relationalQuery :: Relation p r  -- ^ relation to finalize building
+                -> [Keyword]     -- ^ suffix SQL words. for example, `[FOR, UPDATE]`, `[FETCH, FIRST, "3", ROWS, ONLY]` ...
+                -> Query p r     -- ^ finalized query
 relationalQuery = relationalQuery_ config
 
 -- | Make 'Insert' from derived table and monadic builded 'Register' object.
diff --git a/src/Database/Custom/PostgreSQL.hs b/src/Database/Custom/PostgreSQL.hs
--- a/src/Database/Custom/PostgreSQL.hs
+++ b/src/Database/Custom/PostgreSQL.hs
@@ -19,6 +19,7 @@
   delete, deleteNoPH,
   ) where
 
+import Language.SQL.Keyword (Keyword)
 import Database.Relational.Schema.PostgreSQL.Config (config)
 import Database.Relational hiding
   (relationalQuery,
@@ -27,7 +28,9 @@
    delete, deleteNoPH, )
 
 -- | From 'Relation' into typed 'Query' with suffix SQL words.
-relationalQuery :: Relation p r -> QuerySuffix -> Query p r
+relationalQuery :: Relation p r  -- ^ relation to finalize building
+                -> [Keyword]     -- ^ suffix SQL words. for example, `[FOR, UPDATE]`, `[FETCH, FIRST, "3", ROWS, ONLY]` ...
+                -> Query p r     -- ^ finalized query
 relationalQuery = relationalQuery_ config
 
 -- | Make 'Insert' from derived table and monadic builded 'Register' object.
diff --git a/src/Database/Custom/SQLServer.hs b/src/Database/Custom/SQLServer.hs
--- a/src/Database/Custom/SQLServer.hs
+++ b/src/Database/Custom/SQLServer.hs
@@ -19,6 +19,7 @@
   delete, deleteNoPH,
   ) where
 
+import Language.SQL.Keyword (Keyword)
 import Database.Relational.Schema.SQLServer.Config (config)
 import Database.Relational hiding
   (relationalQuery,
@@ -27,7 +28,9 @@
    delete, deleteNoPH, )
 
 -- | From 'Relation' into typed 'Query' with suffix SQL words.
-relationalQuery :: Relation p r -> QuerySuffix -> Query p r
+relationalQuery :: Relation p r  -- ^ relation to finalize building
+                -> [Keyword]     -- ^ suffix SQL words. for example, `[FOR, UPDATE]`, `[FETCH, FIRST, "3", ROWS, ONLY]` ...
+                -> Query p r     -- ^ finalized query
 relationalQuery = relationalQuery_ config
 
 -- | Make 'Insert' from derived table and monadic builded 'Register' object.
diff --git a/src/Database/Custom/SQLite3.hs b/src/Database/Custom/SQLite3.hs
--- a/src/Database/Custom/SQLite3.hs
+++ b/src/Database/Custom/SQLite3.hs
@@ -19,6 +19,7 @@
   delete, deleteNoPH,
   ) where
 
+import Language.SQL.Keyword (Keyword)
 import Database.Relational.Schema.SQLite3.Config (config)
 import Database.Relational hiding
   (relationalQuery,
@@ -27,7 +28,9 @@
    delete, deleteNoPH, )
 
 -- | From 'Relation' into typed 'Query' with suffix SQL words.
-relationalQuery :: Relation p r -> QuerySuffix -> Query p r
+relationalQuery :: Relation p r  -- ^ relation to finalize building
+                -> [Keyword]     -- ^ suffix SQL words. for example, `[FOR, UPDATE]`, `[FETCH, FIRST, "3", ROWS, ONLY]` ...
+                -> Query p r     -- ^ finalized query
 relationalQuery = relationalQuery_ config
 
 -- | Make 'Insert' from derived table and monadic builded 'Register' object.
diff --git a/src/Database/Relational/Schema/PostgreSQL.hs b/src/Database/Relational/Schema/PostgreSQL.hs
--- a/src/Database/Relational/Schema/PostgreSQL.hs
+++ b/src/Database/Relational/Schema/PostgreSQL.hs
@@ -38,7 +38,7 @@
 
 import Database.Relational
   (Query, relationalQuery, Relation, query, query', relation', relation, union,
-   wheres, (.=.), (.>.), in', values, (!), fst', snd',
+   wheres, (.=.), (.>.), not', in', values, (!), fst', snd',
    placeholder, asc, value, unsafeProjectSql, (><))
 
 import Database.Relational.Schema.PostgreSQL.Config
@@ -78,6 +78,7 @@
             -- ("money",        [t| Decimal |]),
             ("bpchar",       [t| String |]),
             ("varchar",      [t| String |]),
+            ("uuid",         [t| String |]),
             ("date",         [t| Day |]),
             ("time",         [t| TimeOfDay |]),
             ("timestamp",    [t| LocalTime |]),
@@ -148,13 +149,12 @@
   wheres $ att ! Attr.atttypid'    .=. typ ! Type.oid'
   wheres $ typ ! Type.typtype'     .=. value 'b'  -- 'b': base type only
 
-  wheres $ typ ! Type.typcategory' `in'` values [ 'B' -- Boolean types
-                                                , 'D' -- Date/time types
-                                                , 'I' -- Network Address types
-                                                , 'N' -- Numeric types
-                                                , 'S' -- String types
-                                                , 'T' -- typespan types
-                                                ]
+  wheres $ not' $ typ ! Type.typcategory' `in'`
+                  values
+                  [ 'C' -- Composite types
+                  , 'P' -- Pseudo-types
+                  , 'X' -- unknown type
+                  ]
 
   asc $ att ! Attr.attnum'