Environment Settings

Whenever you want to run any component of PREDATOR, you must first establish the environment variables needed by the system. This is true of running the server, the clients or the DevStudio workspace on WindowsNT.

On Windows NT:

On Sparc/Solaris:

Although the server is supposed to manage "disks" or "devices", the current implementation supports virtual "disks" that are mapped to files on the file system. Specifically, there are two files that are used: defdisk and reldisk. In addition, there is a log directory which is used to hold log files. The location of these is specified by environment variables defined in P:\setvar.cmd (Solaris: setvar.csh).

Many of the large data types (image, raster, audio, etc.) store their data on the default device, or defdisk. This is a choice made by the data type designer. Relational data is stored in the reldisk. Together, your reldisk and defdisk are where all of your data is stored. If they are erased, your data is lost (in the event of a crash, you can recover from the log files, as long as you do not delete your defdisk and reldisk). In addition, your defdisk and reldisk must always have been created in the same server lifetime, and cannot ever be used apart safely. This is because the reldisk contains records which may reference objects in the defdisk. If one is deleted, the other must be deleted as well, and you should remove your log files too. The command "cleandisk" accomplishes this task without your having to manually delete any files.

The location of your reldisk and defdisk can have a large impact on the performance of your server. If these files are located remotely (on a fileserver over the network), disk I/Os will be very slow. Likewise, the log files should be on a local device.


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