Release 10.1A: OpenEdge Deployment:
Managing 4GL Applications

Temporary file I/O

OpenEdge creates temporary files during each client session. Each operating system has different temporary files. Table 5–4 describes the temporary files.

Table 5–4: Temporary client session files 

File	Description
.dbi	Stores temporary tables.
.lbi	Local before-image file (subtransaction undo).
.pge	Edit buffer contents.
.srt	Temporary sort space; session compile storage.
.trp	Stores Data Dictionary changes until they are saved.

By default, OpenEdge stores the temporary files in the user’s working directory. Use the Temporary Directory (-T) startup parameter to specify an alternate location. When a session ends, OpenEdge deletes these files unless you specify the Save Temp Files (-t) startup parameter. For more information about the Temporary Directory (-T) and Save Temp Files (-t) startup parameters, see OpenEdge Deployment: Startup Command and Parameter Reference .

On UNIX, unless you use the Save Temp Files (-t) startup parameter, you do not see the temporary files in the directory, because they are created unlinked. However, if your system crashes, the UNIX file system recovery program, fsck, finds the files. This program might then prompt you to delete the files. If this occurs, delete them.

On Windows, these temporary files are always visible during a Progress 4GL session, but the file sizes are set to zero. Windows does not record file sizes until files are closed.

Writing to these temporary files creates I/O activity that might slow down client performance. The amount of temporary file I/O activity varies among applications.

You might find that running a particular procedure results in OpenEdge abnormally terminating in a way that indicates the hard disk is full. However, when you check the disk immediately afterward, adequate space is available. One possibility is that temporary files created during a Progress 4GL session become quite large, taking up disk space as they expand. Since OpenEdge erases temporary files at the end of a session, they do not appear when you check the disk. Of the temporary files, the following files are most likely to cause this problem:

Temp table file (.dbi) — OpenEdge uses this file to store temporary tables. If the application uses a lot of temporary tables, this file can grow quite large.
Local before-image file (.lbi) — OpenEdge uses this file to back out of subtransactions and variable value changes. If the local before-image file becomes too large, the procedures probably use a lot of subtransactions. Examine the transaction structure of the application procedures to understand why OpenEdge starts so many subtransactions. For more information about transaction processing, see OpenEdge Development: Progress 4GL Handbook .
Session sort file (.srt) — OpenEdge uses this file to dynamically swap r-code segments in and out of the execution buffer. Use the r-code usage statistics startup parameters to collect information about I/O to the sort file, as explained in the "Monitoring r-code activity" section. Using r-code libraries helps reduce the amount of I/O required to load r-code files. For more information, see the "Using r-code libraries to improve r-code performance" section.

If temporary files grow to exceed disk space, change the application to reduce the size of temporary files, or use the Temporary Directory (-T) parameter to store the temporary files on a disk with sufficient space to hold the files. To optimize performance, place the temporary files on a dedicated disk.