The Extract logic command can write extract files in one of three formats:

This format is specified for an extract file via a configuration property. By default, the format is Internal.

For all formats, the layout of the extract file (in terms of the sequence of fields and the format of data within fields) depends upon the stereotype of the object being extracted.

Generic format

The Generic format is an ASCII text-based format that is common across all AB Suite platforms. Therefore, you should use this format if you need to transfer data via extract files between AB Suite systems running on different platforms.

Number primitives are formatted as plain text with a leading sign (for SignedNumber) and decimal point (for decimal numbers).

Frame format

This format is used when extracting Frame-stereotyped classes, regardless of the format specified on the extract file object (Internal or Generic).

This format is a text-based format and the layout of fields is defined by the Sequence property for the attributes within the Frame. Therefore, you have much more programmatic control over the layout and format of data in an extracted Frame record.

This format is useful when transferring data in and out of an application. An extract file in this format can be used by all programs, including Business Information Server.

Internal format

The Internal format is the default format for extract files. The layout of fields within each record and the format of data within each field is generally in the most efficient format for the platform. For example, Number attributes are formatted in a packed binary format (for example, COBOL COMP) which are slightly different on each platform. Therefore, you cannot use Internal format files to transfer data between AB Suite systems on different platforms, because each platform interprets the Internal format differently.

Use this format when performing operations internal to the application (such as, sorting data without using profiles).

When extracting classes, the format of the file generally depends on the current database structure.

General Notes

When extracting classes with persistent attributes (for example, a persistent Ispec representing a database table) through the Extract LDL verb, only the persistent attributes of that class will be included in the extracted record. That is, the extracted record reflects the database records for that class.

When extracting classes through the Write() extract file method (refer to Extract File Built-In Methods for more information) the extracted records includes the persistent attributes and the non-persistent attributes. The non-persistent attributes follows all of the persistent attributes in the record layout. This layout is said to be the Extended format. Extended format records can only be read by the Read() extract file method.