There are some data sources that do not contain file layout information, including:
| | Report files, such as spool files or print files |
| | Log files, such as security log files or internet log files |
| | Legacy files from some older database systems |
These files contain data records only. To work with log files or legacy files, you need to obtain information about the file layout from the system administrator when you request the data.
If the file layout information is contained in a separate file, it is called an external file definition. Analyzer can read several common external file definitions to correctly format the data for you. Analyzer can use AS/400 FDF specifications, COBOL copybook files, and PL/1 file definitions. The Arbutus zSeries Server can access COBOL copybook files, PL/1 file definitions, and Easytrieve file definitions located on a mainframe server.
A COBOL copybook file definition describes the name, position, and size of each field in a record, as well as the type of data it contains.
If an external file definition is not available, you need to obtain the file layout information from the system administrator and define the data manually. For example, in the legacy file, there may be no column titles, and no indication of where one field ends and another begins.
When Analyzer reads legacy data files, it automatically recognizes the different data types and presents you with an intelligent assessment of the record layout. You can accept Analyzers assessment or change it, and name the columns according to information you have from a record layout.