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3.2 Advanced Options

When you click the "Advanced. . ." button, the Advanced Options window displays.

This window lets you define the location of your data files, compiler options that affect the way numeric data is stored, and read/write permissions.

Complete the fields as described below.

File Prefix

This field specifies the directory where the data files are located--by default, this is the same directory specified for data dictionaries when initially defining the data source name. If your data files reside in a different directory than the data dictionaries, change the value of File Prefix to specify the correct location. If necessary, you can enter multiple directories in this field--just separate the different directory names by spaces. When AcuODBC opens a file, it looks for the file in the directories listed here, starting from left to right. If this field is blank, AcuODBC looks for the file in the data dictionary directory specified before.

File Suffix

In this field, specify the file extension used for your data files (e.g., "dat"). When AcuODBC looks for a file, it looks only at files with the extension listed in this box. If you leave this box blank, it will look for files with no extension in the data dictionary or File Prefix directory indicated.

Julian Base Date

In this field, specify the Julian base date to be used in defining Julian date formats. The information in this field should have the following format:

yyyy/mm/dd

where yyyy is the year, mm is the month, and dd is the day.

By default, 1900/01/01 is the base date (January 1, 1900). 0001/01/01 is the minimum base date allowed.

Signed Index

If your application has any numeric fields that belong to a key or index, you can have a problem with record ordering when a negative value occurs in the field. (A negative value results in an index that is not ordered.) Set this option to "No" to disqualify numeric signed fields from being indexes.

There is some performance degradation when this option is set to "No." Since it is the case that most signed fields included in a key do not contain negative numbers, you might want to set this option to "Yes" to avoid the performance penalty.

Read Only

This is available only for read/write versions of AcuODBC. This entry establishes the default read/write permission for all the files belonging to this DSN. Select "Yes" if the files are read-only. Select "No" if they are read and write approved. Field (column) level read/write protection can be further defined by adding the COMMENT ACUODBC READ-ONLY and COMMENT ACUODBC HIDDEN directives to the file descriptor (FD) for your COBOL program. Refer to Section 7.3 Using Directives for instructions.

Font

In this field, specify the character set to be used for accepting and displaying data on the screen. This entry can assume the following values:

Value
Description
ANSI
Use the ANSI graphical font
OEM
Use the MS-DOS font or OEM character set
The OEM character set is for international users who want to display a specific set of characters on their Windows terminal. To map these characters to a character set on another machine, you can create a map file and specify the map file name under "International Character Handling" below. By default, the ANSI font is used.

Password Request

This field allows you to define a password for connecting to remote files via AcuServer. By default, local access is assumed, so the password is turned off.

To define a password for remote access, click the "Use:" radio button in the Password Request field, then type a password into the entry box to the right of this button. This password is automatically sent to AcuServer when remote access is requested.

If you want to be prompted for a password to make access more secure, click the "Ask" button. Now, whenever someone tries to connect to remote files, he or she is prompted to enter a username and password. Only users with the correct password will be granted access to the remote data source.

File Case

In this field, specify the case of the Vision or relative filenames in your destination directory (applies to UNIX filenames only). By default, the filenames are assumed to be in upper case. If your filenames are lower case, you must click the "Lower" radio button here, or AcuODBC will not be able to find your files.

Compilation Options

If you specified the "-Dci", "-Dcm", or "-Dcn" compiler option when compiling your ACUCOBOL-GT program, click the radio button for that option here. This tells AcuODBC which data storage convention was used to create your data files. Other conventions, like "-Dm", are recognized automatically. Possible values include:

Value
Description
Default (-Dca)
The ACUCOBOL-GT storage convention
-Dci
The IBM storage convention
-Dcm
The Micro Focus storage convention
-Dcn
A derivative of the IBM storage convention. Uses the same format as "-Dci", except that positive COMP-3 items use "x0B" as the positive sign value instead of "x0C".
These options affect the way in which numeric COMP-3 fields are stored. For example, the standard way to represent the value "-123" in a field, declared as PIC S9(5) COMP-3, is "x00123F." But if you compile the program using the "-Dca" option, the representation becomes "x00123C."

Because the information about representing numeric compressed data is not contained in the Vision or relative file, you must specify if one of the options listed in the "Compilation Options" frame was used when the ACUCOBOL-GT programs were compiled. For more information on these options, refer to "Data Storage Options" in the ACUCOBOL-GT User's Guide.

International Character Handling:

Default Map File

Enter the name and path of the map file to be used (if any) to map special characters in your character set to their decimal or hexadecimal equivalent in another character set before they are passed to or from the Vision or relative file system. This file lets you reconcile the character encoding between two machines that use different codes for the same characters.

You can specify a local or remote directory for the map file, or leave blank to decline the use of a map. To specify a local directory, click the "Browse" button and browse to the desired directory. To specify a remote directory, use the following syntax:

@server-name:directory-path

where server-name is the name of the UNIX or NT server on which the map file resides. To simplify access and maintenance of XFDs and map files, we recommend that you store the XFD files along with the map files on the server.

When creating a map file, you need to re-map only those values that vary between the two character sets (e.g., vowels with a grave accent, acute accent, circumflex, tilde, etc.) You can check the values of specific characters using the Windows Character Map accessory in the PC environment, or by referring to your UNIX man pages in the UNIX environment.

The map file should contain two values per line: the first indicating the decimal or hexadecimal value of the special character on the client machine and the second indicating the decimal or hexadecimal value of the corresponding character on the server machine. (Hexadecimal values use the standard "0x" notation.) For instance:

0x90 0xC9

maps "E" (acute) in the IBM PC character set to "E" (acute) in the ISO8859-1 character set using hexadecimal notation.

144 201

gives the same mapping using decimal notation.

You can use the pound sign (#) to indicate a comment.

Note to application developer: The map will be used to translate only alphanumeric fields; but it will translate all alphanumeric fields, including group items and items subject to a REDEFINES clause. If this is not a desired behavior, you may need to restructure your program to avoid these clauses by passing the elementary items instead of the group item, or passing an item from the REDEFINES clause instead of the first reference.

File Alias:

Logical Name

This entry allows you to specify absolute pathnames for special data files that are not stored in the directories found in the File Prefix entry.

The logical name corresponds to the logical name indicated in the data dictionary file. Usually, it is equal to the name used in the SELECT clause of the ENVIRONMENT DIVISION of the COBOL program. You can modify this logical name with the "NAME" directive when building the data dictionary files.

Physical Name

Type the full path (including filename) where the file specified at the logical name entry is stored. To add the logical-to-physical name mapping to the Windows registry, click the "Add/Update" button. The file mapping displays in the list box on the bottom of the Advanced Options screen.

Write Permission

This is available only for read/write versions of AcuODBC. In this section, specify read/write permissions for the data files defined in "Logical Name." You can specify "DSN default," "Read/Write," or "Read Only." "DSN default" tells AcuODBC to use the read/write default established with the Read Only entry at the top of this screen. If you select a setting other than the default, be sure to click the "Add/Update" button to place the change in effect.

Note: Field- or column-level read/write protection can be further defined by adding the COMMENT ACUODBC READ-ONLY and COMMENT ACUODBC HIDDEN directives to the file descriptor (FD) for your COBOL program. Refer to Section 7.3 Using Directives for instructions.

Deleting File Mapping Definitions

The list box on the bottom of the Advanced Options screen displays a list of file mapping definitions made with the "Logical Name" and "Physical Name" entry fields. If you want to delete any of the items listed in this box, highlight the item, then click the "Delete" button to the right of the box.