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

The information in this article applies to:

• Microsoft Visual FoxPro for Windows, version 3.0

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

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.

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"