Other Relevant FAQs

Data File Performance

Caliach FAQ: Data File Segments

This technical note explains the structure of a Caliach Vision or CaliachMRP data file and explains how to manage segments.

What is the structure of an Omnis Data File?

A data file can consist of up to fifteen separate operating system files called segments, each of which can be up to 256 megabytes or 512,000 blocks of 512 bytes. If the name of the first segment is MyData.df1, any others will be MyData.df2, MyData.df3, etc up to MyData.dff. If there is only one segment, Omnis will automatically add blocks as space is required during normal working. Once you have more than one segment, there is no automatic addition of space. Omnis will not automatically add a segment either. When Omnis opens a datafile with more than one segment, it treats it as though it were a single large file. Any data or parts of data can reside in any segment.

How do I know whether I need to add a segment?

Examine your data file and if it is close to 256Mb, you are well advised to either make space in the datafile by archiving off history, or add a segment. If you inadvertantly reach the 256Mb limit and the program needs space, you will receive a message saying "Data file is full." and any transaction in progress at the time will only partly be stored (this may lead to imballancing accounts or incomplete kitting, etc).

How do I add a segment in CaliachMRP?

With only yourself on the system, operate File >> Install Utilities Menu and then from the Utilities menu operate Utilities >> Data File Tools >> Examine Data File. This will open a window and also add a Data files menu to the menu bar. Operate Data files >> Change Data File Size. In the subsequent window you will see a list of segments on the left. The size of the segment selected in the list is shown on the right of the window. You can simply put in a larger number to extend the segment up to its limit of 512000 (Remember, the first segment will not auto-extend if there is a second segment.). To add a segment, click on the Add Segment button. You will then be asked to select a directory for that segment. This can be in the same directory as the last segment in the list or any directory listed against the OMNIS path variable (set in the autoexec.bat file of your computer). Having added a segment, you should give it plenty of space by entering a blocks figure. Remember, once you have a second segment the datafile is fixed in size until you manually change it's size.

How do I add a segment in Caliach Vision?

With only yourself on the system, operate File >> Advanced >> Re-Size Data File Size. In the subsequent window you will see a list of data files on the left and segments of the selected datafile on the right. The size of the segment selected in the list is shown below. You can simply put in a larger number to extend the segment up to its limit of 512000 (Remember, the first segment will not auto-extend if there is a second segment.). To add a segment, click on the Add Segment button. This will create an additional segment in the same directory as the last segment in the list. Having added a segment, you should give it plenty of space by entering a blocks figure. Remember, once you have a second segment the datafile is fixed in size until you manually change it's size.

Can I copy or re-locate a multi-segment data file?

Yes, but you will need to ensure that Set Omnis= 'path to the segment directory'[;'another path to another segment directory'] is in your autoexec.bat file. This is becase Omnis first looks in the first segment directory and then in the directories listed in directories listed in the system's Omnis variable. On a Macintosh there is no such beast as the Omnis variable so Omnis first looks in the first segment's folder, then the current library folder (CALIACH or Vision), and then in the Omnis folder.