DSNTIAUL Files

Restriction: This topic applies to Windows environments only.

Use this format to export data from an XDB Server table or view into the DSNTIAUL file format. DSNTIAUL is a mainframe format (File UNLOAD Utility) that is used with DB2.

When you use the Browse button to choose a target file, export will search for the selected file format. DSNTIAUL format is indicated by the file name extension .dsn.

In DSNTIAUL files, all data is consecutive (no delimiters), and padded for the full length of the field, making it more like a columnar (fixed-format) ASCII file. If nulls are allowed, a one-byte trailer after each field indicates null status:

A zero (0) indicates NOT NULL.
An EBCDIC question mark (?) indicates NULL.

Data types are exported as follows:

Text fields are stored in EBCDIC format.
Date, Time, and Timestamp fields are stored as text.
Decimal and Money fields are stored in BCD format.
Smallint fields are stored in binary format. As the field is read, its byte order is automatically transformed from standard Intel format (where the least significant byte is first) into standard binary format (where the most significant byte is first).
Integer fields are stored in binary format. As the field is read, its byte order is automatically transformed from standard Intel format (where the least significant byte is first) into standard binary format (where the most significant byte is first).
Float fields are stored in binary format (different from PCs).
Varchar fields have a two-byte header containing the length of the text.

The DSNTIAUL file format directly depends on the null permissions of the exported table. Therefore the null permissions of the table you import into must match the table's null permissions from which you exported.

The DSNTIAUL format uses a page-oriented storage for each record in the table. The typical page size is approximately 4K bytes. When the table contains a long varchar field (which is 4056 bytes long), information in this field may be truncated. The size of the long varchar field is truncated to the page size minus the sum of the sizes of the other fields in the table.

Export to DSNTIAUL format can make use of Code Page Support. This allows you to export objects to DSNTIAUL in EBCDIC and retain object names containing foreign characters. By default, Export assumes character data is stored in the source tables using the American ASCII character set and converts it to the American ASCII character set before writing it to a target file. See "ASCII Table" for a listing of the decimal ASCII character sets.

You can have the Export utility translate character data containing characters from any international EBCDIC character set using the code page feature in Export. For the EBCDIC code page, use the default EBCDIC character set for your country. Code page support is provided by the INCCSID and OUTCCSID fields in the SYSIBM.SYSSTRINGS table at the SYSTEM location.

The following table shows the structure of the SYSIBM.SYSSTRINGS table.

Column Name	Type	Length	Description
INCCSID	int	2	Code page number to translate FROM.
OUTCCSID	int	2	Code page number to translate TO.
TRANSTYPE	CHAR	2	Not used by Export.
ERRORBYTE	CHAR	1	Not used by Export.
SUBBTYPE	CHAR	1	Not used by Export.
TRANSPROC	CHAR	8	Not used by Export.
IBMREQD	CHAR	1	Not used by Export.
TRANSTAB	VARCHAR for bit data	256	Translation table to convert from INCCSID code page to OUTCCSID code page (ASCII to EBCDIC)

When the Export utility uses code page options, the values entered for INCCSID and OUTCCSID are compared with values in the system table SYSIBM.SYSSTRINGS. The matching record in the table contains the translation table used to convert XDB Server data in ASCII format to DSNTIAUL data in EBCDIC format.