improved postgresql support

src/main/java/com/alibaba/druid/sql/dialect/postgresql/parser/PGExprParser.java

@@ -40,6 +40,14 @@ public class PGExprParser extends SQLExprParser {
         this.aggregateFunctions = AGGREGATE_FUNCTIONS;
         this.dbType = JdbcConstants.POSTGRESQL;
     }
+    
+    @Override
+    public SQLDataType parseDataType() {
+        if (lexer.token() == Token.TYPE) {
+            lexer.nextToken();
+        }
+        return super.parseDataType();
+    }
 
     @Override
     public PGOrderBy parseOrderBy() {

src/main/java/com/alibaba/druid/sql/dialect/postgresql/parser/PGLexer.java

@@ -63,6 +63,7 @@ public class PGLexer extends Lexer {
         map.put("FALSE", Token.FALSE);
         map.put("ARRAY", Token.ARRAY);
         map.put("IF", Token.IF);
+        map.put("TYPE", Token.TYPE);
 
         DEFAULT_PG_KEYWORDS = new Keywords(map);
     }

src/main/java/com/alibaba/druid/sql/parser/Token.java

@@ -154,6 +154,7 @@ public enum Token {
     RETURNING("RETURNING"),
     COMMENT("COMMENT"),
     OVER("OVER"),
+    TYPE("TYPE"), 
     
     // oracle
     START("START"),