StringBuilder buf = new StringBuilder();
		for ( int i=0; i < tables.length; i++ ) {
			final String tableName = dialect.quote( normalizer.normalizeIdentifierQuoting( tables[i] ) );
			if ( tables.length > 1 ) {
				buf.append( "select max(" ).append( column ).append( ") as mx from " );
			}
			buf.append( Table.qualify( catalog, schema, tableName ) );
			if ( i < tables.length-1 ) {
				buf.append( " union " );
			}
		}
		if ( tables.length > 1 ) {
			buf.insert( 0, "( " ).append( " ) ids_" );
			column = "ids_.mx";
		}

		sql = "select max(" + column + ") from " + buf.toString();