Q68339: ISAM Files Cannot Be Opened by Multiple Networked Workstations

Article: Q68339
Product(s): See article
Version(s): 7.00 7.10 | 7.10
Operating System(s): MS-DOS | OS/2
Keyword(s): ENDUSER | SR# S910107-151 docerr | mspl13_basic
Last Modified: 16-JAN-1991

The note on page 336 of the "Microsoft BASIC 7.0: Programmer's Guide"
for Microsoft BASIC PDS 7.00 and 7.10 incorrectly states that you can
open an ISAM database for read-only by one BASIC process and then have
another BASIC process open it for reading as well.

If a database is already open, even if it is opened for read-only
access, the ISAM engine will generate a "Permission denied" error when
another process attempts to open the database. If the first process
closes the file, then the second process can access it.

This information apples to Microsoft BASIC PDS versions 7.00 and 7.10
for MS-DOS and 7.10 for MS OS/2.

Note that "processes" refer to two separate programs or users
attempting to access a file on a network server. However, this can
also apply to two separate programs under multitasking, systems such
as OS/2 or Microsoft Windows.

For an in-depth explanation for why BASIC PDS 7.10 does not yet
support multiuser ISAM, query on the following:

   why and BASIC and multiuser and ISAM

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