public DatabaseMetadata(Connection connection,
    Dialect dialect) throws SQLException 
{
	       
		this(connection, dialect, true);
}

 public DatabaseMetadata(Connection connection,
    Dialect dialect,
    boolean extras) throws SQLException 
{
		sqlExceptionConverter = dialect.buildSQLExceptionConverter();
		meta = connection.getMetaData();
		this.extras = extras;
		initSequences(connection, dialect);
}

 public TableMetadata getTableMetadata(String name,
    String schema,
    String catalog,
    boolean isQuoted) throws HibernateException 
{
	            
		Object identifier = identifier(catalog, schema, name);
		TableMetadata table = (TableMetadata) tables.get(identifier);
		if (table!=null) {
			return table;
		}
		else {
			try {
				ResultSet rs = null;
				try {
					if ( (isQuoted && meta.storesMixedCaseQuotedIdentifiers())) {
						rs = meta.getTables(catalog, schema, name, TYPES);
					} else if ( (isQuoted && meta.storesUpperCaseQuotedIdentifiers()) 
						|| (!isQuoted && meta.storesUpperCaseIdentifiers() )) {
						rs = meta.getTables( 
								StringHelper.toUpperCase(catalog), 
								StringHelper.toUpperCase(schema), 
								StringHelper.toUpperCase(name), 
								TYPES 
							);
					}
					else if ( (isQuoted && meta.storesLowerCaseQuotedIdentifiers())
							|| (!isQuoted && meta.storesLowerCaseIdentifiers() )) {
						rs = meta.getTables( 
								StringHelper.toLowerCase(catalog), 
								StringHelper.toLowerCase(schema), 
								StringHelper.toLowerCase(name), 
								TYPES 
							);
					}
					else {
						rs = meta.getTables(catalog, schema, name, TYPES);
					}
					while ( rs.next() ) {
						String tableName = rs.getString("TABLE_NAME");
						if ( name.equalsIgnoreCase(tableName) ) {
							table = new TableMetadata(rs, meta, extras);
							tables.put(identifier, table);
							return table;
						}
					}
					log.info("table not found: " + name);
					return null;
				}
				finally {
					if (rs!=null) rs.close();
				}
			}
			catch (SQLException sqle) {
				throw JDBCExceptionHelper.convert(
                        sqlExceptionConverter,
				        sqle,
				        "could not get table metadata: " + name
					);
			}
		}
}

 public boolean isSequence(Object key) 
{
		if (key instanceof String){
			String[] strings = StringHelper.split(".", (String) key);
			return sequences.contains( strings[strings.length-1].toLowerCase());
		}
		return false;
}

 public boolean isTable(Object key) throws HibernateException 
{
 		if(key instanceof String) {
			Table tbl = new Table((String)key);
			if ( getTableMetadata( tbl.getName(), tbl.getSchema(), tbl.getCatalog(), tbl.isQuoted() ) != null ) {
 				return true;
 			} else {
 				String[] strings = StringHelper.split(".", (String) key);
 				if(strings.length==3) {
					tbl = new Table(strings[2]);
					tbl.setCatalog(strings[0]);
					tbl.setSchema(strings[1]);
					return getTableMetadata( tbl.getName(), tbl.getSchema(), tbl.getCatalog(), tbl.isQuoted() ) != null;
 				} else if (strings.length==2) {
					tbl = new Table(strings[1]);
					tbl.setSchema(strings[0]);
					return getTableMetadata( tbl.getName(), tbl.getSchema(), tbl.getCatalog(), tbl.isQuoted() ) != null;
 				}
 			}
 		}
 		return false;
}

 public String toString() 
{
		return "DatabaseMetadata" + tables.keySet().toString() + sequences.toString();
}