PRB: SEEK Finds Old and New Data With Optimistic Buffering (190496)

SYMPTOMS

When you use the SEEK command to find data and then replace that data with another value, SEEK finds both the old value and the new value if the buffering is set to optimistic table buffering.

STATUS

Microsoft has confirmed this to be a problem in the Microsoft products listed at the beginning of this article. We are researching this problem and will post new information here in the Microsoft Knowledge Base as it becomes available.

MORE INFORMATION

The Customer table, used in the Sample Code example, ships as sample data in Visual FoxPro 3.0x, 5.0x, and 6.0. Before running the program, use the SET DEFAULT TO command to point to the folder that contains the Customer table.

Steps to Reproduce Behavior

Issue the following commands in the Command window or create a .prg file and run the program.

Sample Code

   SET MULTILOCKS ON
   USE customer
   =CURSORSETPROP('Buffering',5)
   SET ORDER TO cust_id
   ?SEEK('AROUT')
   REPLACE CUST_ID WITH 'AROUS'
   ?SEEK('AROUT')
   ?SEEK('AROUS')

Note that the SEEK function returns true for the old value "AROUT" and for the new value "AROUS". Setting the buffering to optimistic row buffering or to pessimistic buffering, allows the SEEK function to find only the new value.