Q139091: FIX: "INDEX Internal Consistency Error" Occurs with SET KEY

Article: Q139091
Product(s): Microsoft FoxPro
Version(s): 3.00
Operating System(s): 
Keyword(s): kbbuglist kbfixlist
Last Modified: 24-MAR-2000

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The information in this article applies to:

- Microsoft Visual FoxPro for Windows, version 3.0 
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SYMPTOMS
========

An "INDEX Internal Consistency Error" (ICE) occurs when you browse a cursor with
optimistic or pessimistic table buffering set and a SET KEY command active.
Running a form containing a grid with its RecordSource property set to a table
that has buffering and SET KEY active causes the same error.

WORKAROUND
==========

Include the records you want by using a method other than the SET KEY command.
For example, use the SET FILTER command or create an index tag that includes
only those records that you want.

-or-

Use row buffering rather than table buffering.

STATUS
======

Microsoft has confirmed this to be a problem in the Microsoft products listed at
the beginning of this article. This problem was corrected in Visual FoxPro 3.0b
for Windows.

MORE INFORMATION
================

Steps to Reproduce Problem
--------------------------

Running the following example code will cause Visual FoxPro 3.0 to quit. Please
close any important files in Visual FoxPro before running either of these tests.
These examples use the Customer table from Testdata.dbc in the \Vfp\Samples\Data
directory.

To reproduce the problem in a BROWSE, run the following code in a program (.prg
file) or in the Command window:

     SET MULTILOCKS ON
     USE customer ORDER cust_id
     =CURSORSETPROP('buffering',4)
     SET KEY TO RANGE "T","V"
     BROWSE

When the BROWSE window appears, the "INDEX Internal Consistency Error" error will
also appear. When you press a key, Visual FoxPro quits.

To reproduce the problem in a grid control on a form:

1. Create a new form, and place the following code in the form's Load event:

     SET MULTILOCKS ON
     SET ORDER TO cust_id
     =CURSORSETPROP('buffering',4)
     SET KEY TO RANGE "T","V"

2. Add the Customer table to the Data Environment of the form.

3. Create a grid from Customer by dragging the Customer table by its title bar
  from the Data Environment to the form.

4. Run the form, and click one of the scroll bars of the grid, or press the up
  arrow to move the record pointer. At this point, the "INDEX Internal
  Consistency Error" appears. Pressing a key will close Visual FoxPro.

In other circumstances, other errors may occur. The error "Table has no index
order set" appears if the commands SKIP and then SKIP -1 are issued in the
Command window after running the previously described form.

Additional Notes
----------------

- The error occurs with the Buffering property of the cursor set to 4
  (Pessimistic Table Buffering) or 5 (Optimistic Table Buffering).

- Buffering settings of 1 (None), 2 (Pessimistic Row), or 3 (Optimistic Row)
  work correctly.

- If a SET FILTER command is used in place of the SET KEY command, no error
  occurs. For example, instead of using this command:

        SET KEY TO RANGE "T","V"

  Use the following command to produce the same result:

        SET FILTER TO LEFT(cust_id,1)>="T" AND LEFT(cust_id,1)<="V"

Additional query words: VFoxWin fixlist3.00b buglist3.00

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Keywords          :  kbbuglist kbfixlist
Technology        : kbVFPsearch kbAudDeveloper kbVFP300
Version           : 3.00
Issue type        : kbbug
Solution Type     : kbfix

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