The structure of ACL tables

Data in ACL is contained in tables. When you view and analyze data in ACL, you are doing the work in an ACL table. ACL tables have a three-part structure:

Understanding how ACL tables are structured is fundamental to working effectively in ACL. Figure 1 illustrates the structure of an ACL table.

Figure 1. ACL table structure

The source data file

The source data file contains raw data, without ACL formatting information such as field names. It exists outside the ACL project. It can reside in the same Windows folder as the ACL project, or it can be located elsewhere on the same computer, or in a network location, or in a database.

In most cases, when you create a new ACL table, ACL copies and imports source data into a new ACL source data file saved in a flat file format with a .fil extension. The .fil file serves as the basis for the ACL table. The flat file format has fixed-length fields, and records identified by a fixed length, or by carriage return and line feed codes, making it an easy format to interpret. In some cases, such as .dbf and .txt files, ACL can connect directly to the existing source data file, and a .fil file is not required or created.

The table layout

The table layout is a structured interpretation of the raw data in the source data file. The table layout contains metadata such as field definitions, which specify field names, the start position of fields, the length of fields, the data type of fields, and so on. ACL requires the table layout in order to make sense of the raw data. The table layout also specifies the location of the source data file. The table layout is part of the ACL project file (.acl).

One or more views

The view is an arrangement of named columns, with numbered records, that displays the structured data from the table layout. Views also format the data for ACL reports. You can create multiple views for the same table, each of them with a different selection and arrangement of columns. The view is part of the ACL project file (.acl).

Related concepts
Working with table layouts
Working with ACL views

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