Table Definition Overview
in AXIS Users Guide - Basics of Table Definition

Once a logical file has been created to link DataLink with the extract source file, it is necessary to set up tables that will convert the data into a format that AXIS can process.  This is done through the creation of module specific mandatory and user defined tables.

Creating a Table

Begin by selecting View / DataLink / Table from the menu bar.  This will open the DataLink Table object list. To create a new table, click on the Action button and select New; the Create DataLink Table wizard will open.

1. Step one of the DataLink Table Wizard allows you to select the type of table you wish to create.  The available options will be depend on which module you are currently working within, but the table definition process remains the same. For this example, let us consider working with the Policy Information table.  Once you have selected the type of table you wish to create, give the table a meaningful name and click the Next button.
2. Step two allows you to define whether the table will be loaded from a source file and also allows you to select a source file if it is to be used. Valid DataLink logical files will be displayed in the drop down list.  Select your source file and table type, then click Next to proceed to the next step.
3. Step three allows you to select which records will populate this table by establishing filtering based on a record code. If the file contains records of varying record layouts, a Record Code field must be present at the same location in all record formats that will indicate the type of record and thus its layout. If the valid record code is defined, along with the starting position of the field in the source record, then records with that code are included in the loading process. Alternatively, you may choose to define which record code is invalid (i.e. skipped) by inserting the value of that code on the Table Definition form, and specifying a starting position of the field in the source record preceded by a negative sign. Record Codes are tested at the very beginning of the loading process and are thus a very time efficient way to filter out the required records. The Record Code can also be used for filtering purposes other than just record layout, such as business type (reinsurance or direct) or product type, but you are limited to entering only one valid (or invalid) Record Code. Note, however, that the specified valid code may include the wild card character "?" as part of the code, which will effectively allow you to select multiple codes at once. Other record filtering approaches may provide even more power and flexibility. 
4. Click Finish to complete the wizard.

When the Wizard exits, the field definition window for the newly created table will open.  If the table is not of type user defined, the field definition window will contain a number of mandatory fields (designated by an M in the object list) which AXIS requires to perform its calculations.  These, along with any user added optional fields (O) are the fields that will be used in AXIS calculations. User defined fields (U) are used for data analysis and reporting or to assist in defining calculated mandatory fields and/or optional fields. User defined fields are not used in AXIS calculations.

You can modify a field by highlighting it and clicking on the Properties button at the bottom of the Field Definition Window. The Main tab that pops up automatically allows you to rename a user defined field, set the source of a field (Input, Calculated or Default) and make notes in the Notepad regarding a specific field.