Basic ISAM Creates Two Temporary Files During Operation (71236)


The information in this article applies to:

  • Microsoft Visual Basic for MS-DOS
  • Microsoft Basic Professional Development System (PDS) for MS-DOS and MS OS/2 7.0
  • Microsoft Basic Professional Development System (PDS) for MS-DOS and MS OS/2 7.1
This article was previously published under Q71236

SUMMARY

During operations, ISAM creates two temporary files that are used for maintenance and transactions. The first file gets created when an ISAM database is opened or created, and the second temporary file is created during block processing.

The information in this article is also included in the Help file provided with the Standard and Professional Editions of Microsoft Visual Basic for MS-DOS, version 1.0.

MORE INFORMATION

When an ISAM database is opened or created, a 6,144-byte file with a random name is created in the directory pointed to by the "TMP" environment variable, or if that does not exist, the file is created in the current directory. If ISAM cannot create this file when opening a database, a run-time error 70: "Permission Denied" occurs on the OPEN statement. This file is needed for database maintenance by the ISAM engine and is deleted when the database is closed. (This file is used for temporary work space when building indexes and on rare occasions when reading a read-only database.)

The second type of temporary file that can be generated is the transaction log as outlined on Page 136 of the "Microsoft Visual Basic for MS-DOS: Professional Edition Features" manual for Visual Basic for MS-DOS, version 1.0; and on Page 377 of the "Microsoft Basic 7.0: Programmer's Guide" for Basic PDS for MS-DOS, version 7.0 and 7.1.

For more information on Microsoft Basic ISAM files, query on the following words in the Microsoft Knowledge Base:

ISAM and files and PDS

The second type of temporary file that can be generated is the transaction log as outlined on Page 136 of the "Microsoft Visual Basic for MS-DOS: Professional Edition Features" manual for Visual Basic for MS-DOS, version 1.0.
Modification Type:MinorLast Reviewed:8/16/2005
Keywords:KB71236
©2004 Microsoft Corporation. All rights reserved.