diff -r a802a45383bb modules/unsupported/jdbc-ng/jdbc-core/src/main/java/org/geotools/jdbc/JDBCDataStore.java
--- a/modules/unsupported/jdbc-ng/jdbc-core/src/main/java/org/geotools/jdbc/JDBCDataStore.java	Fri Jun 26 07:25:55 2009 +0800
+++ b/modules/unsupported/jdbc-ng/jdbc-core/src/main/java/org/geotools/jdbc/JDBCDataStore.java	Sun Jun 28 16:06:51 2009 +0800
@@ -125,10 +125,17 @@
     
     /**
      * The native SRID associated to a certain descriptor
+     * TODO: qualify this key with 'org.geotools.jdbc'
      */
     public static final String JDBC_NATIVE_SRID = "nativeSRID";
     
     /**
+     * The key for attribute descriptor user data which specifies the original database column data 
+     * type.
+     */
+    public static final String JDBC_NATIVE_TYPENAME = "org.geotools.jdbc.nativeTypeName";
+    
+    /**
      * name of table to use to store geometries when {@link #associations}
      * is set.
      */
diff -r a802a45383bb modules/unsupported/jdbc-ng/jdbc-core/src/main/java/org/geotools/jdbc/JDBCFeatureSource.java
--- a/modules/unsupported/jdbc-ng/jdbc-core/src/main/java/org/geotools/jdbc/JDBCFeatureSource.java	Fri Jun 26 07:25:55 2009 +0800
+++ b/modules/unsupported/jdbc-ng/jdbc-core/src/main/java/org/geotools/jdbc/JDBCFeatureSource.java	Sun Jun 28 16:06:51 2009 +0800
@@ -50,6 +50,7 @@
 import org.opengis.feature.Association;
 import org.opengis.feature.simple.SimpleFeature;
 import org.opengis.feature.simple.SimpleFeatureType;
+import org.opengis.feature.type.AttributeDescriptor;
 import org.opengis.filter.Filter;
 import org.opengis.referencing.crs.CoordinateReferenceSystem;
 
@@ -230,7 +231,8 @@
                     }
 
                     //figure out the type mapping
-
+                    String nativeTypeName = columns.getString("TYPE_NAME");
+                    
                     //first ask the dialect
                     Class binding = dialect.getMapping(columns, cx);
 
@@ -242,8 +244,7 @@
 
                     if (binding == null) {
                         //determine from type name mappings
-                        String typeName = columns.getString("TYPE_NAME");
-                        binding = getDataStore().getMapping(typeName);
+                        binding = getDataStore().getMapping(nativeTypeName);
                     }
 
                     //if still not found, resort to Object
@@ -251,6 +252,9 @@
                         getDataStore().getLogger().warning("Could not find mapping for:" + name);
                         binding = Object.class;
                     }
+                    
+                    //store the native database type in the attribute descriptor user data
+                    ab.addUserData(JDBCDataStore.JDBC_NATIVE_TYPENAME, nativeTypeName);
 
                     //nullability
                     if ( "NO".equalsIgnoreCase( columns.getString( "IS_NULLABLE" ) ) ) {
@@ -258,6 +262,8 @@
                         ab.minOccurs(1);
                     }
                     
+                    AttributeDescriptor att = null;
+                    
                     //determine if this attribute is a geometry or not
                     if (Geometry.class.isAssignableFrom(binding)) {
                         //add the attribute as a geometry, try to figure out 
@@ -279,16 +285,25 @@
                         ab.setCRS(crs);
                         if(srid != null)
                             ab.addUserData(JDBCDataStore.JDBC_NATIVE_SRID, srid);
-                        tb.add(ab.buildDescriptor(name, ab.buildGeometryType()));
+                        att = ab.buildDescriptor(name, ab.buildGeometryType());
                     } else {
                         //add the attribute
                         ab.setName(name);
                         ab.setBinding(binding);
-                        tb.add(ab.buildDescriptor(name, ab.buildType()));
+                        att = ab.buildDescriptor(name, ab.buildType());
                     }
+                    
+                    //call dialect callback
+                    dialect.postCreateAttribute( att, columns, tableName, databaseSchema, cx);
+                    tb.add(att);
                 }
 
-                return tb.buildFeatureType();
+                //build the final type
+                SimpleFeatureType ft = tb.buildFeatureType();
+
+                //call dialect callback
+                dialect.postCreateFeatureType(ft, metaData, databaseSchema, cx);
+                return ft;
             } finally {
                 getDataStore().closeSafe(columns);
             }
diff -r a802a45383bb modules/unsupported/jdbc-ng/jdbc-core/src/main/java/org/geotools/jdbc/SQLDialect.java
--- a/modules/unsupported/jdbc-ng/jdbc-core/src/main/java/org/geotools/jdbc/SQLDialect.java	Fri Jun 26 07:25:55 2009 +0800
+++ b/modules/unsupported/jdbc-ng/jdbc-core/src/main/java/org/geotools/jdbc/SQLDialect.java	Sun Jun 28 16:06:51 2009 +0800
@@ -719,6 +719,42 @@
     public void postCreateTable(String schemaName, SimpleFeatureType featureType, Connection cx)
         throws SQLException {
     }
+    
+    /**
+     * Callback which executes after an attribute descriptor has been built from a table column.
+     * <p>
+     * The result set <tt>columnMetadata</tt> should not be modified in any way (including scrolling)
+     * , it should only be read from.
+     * </p>
+     * <p>
+     * This base implementation does nothing, subclasses should override as need be.
+     * </p>
+     * @param att The built attribute descriptor.
+     * @param columnMetadata The database metadata about the column.
+     * @param tableName The name of the table containing the column
+     * @param schemaName The name of the database scheam containing the table containing the column
+     * @param cx The database connection.
+     */
+    public void postCreateAttribute(AttributeDescriptor att, ResultSet columnMetadata, String tableName, 
+        String schemaName, Connection cx ) throws SQLException {
+        
+    }
+    
+    /**
+     * Callback which executes after a feature type has been built from a database table.
+     * <p>
+     * This base implementation does nothing, subclasses should override as need be.
+     * </p>
+     * @param featureType The build feature type.
+     * @param metadata The database metadata.
+     * @param schemaName The name of the database scheam containing the table containing the column
+     * @param cx The database connection.
+     */
+    public void postCreateFeatureType(SimpleFeatureType featureType, DatabaseMetaData metadata, 
+        String schemaName, Connection cx) 
+        throws SQLException {
+        
+    }
 
     /**
      * Obtains the next value of the primary key of a column.