V4WS 1.11 - SetNull deletion control

[Ruslan Zasukhin]

On 17/9/07 8:39 AM, "Steven Ronald" <stevenrt39 at yahoo.com.au> wrote:

Hi Steven,

> I make a daughter table with an ObjectPtr field
> relating it to a parent table with deletion control
> specified as SetNull.
> 
> Now when I delete a record in the parent table, the
> related records in the daughter table will not be
> deleted but the ObjectPtr field of the related records
> is set to NULL.
> 
> My question:
> 
> If I try to obtain a cursor that seeks to update the
> daughter record with kServer, kReadWrite, kRandom
> options just when Valentina sets the ObjectPtr field
> of this daughter record to Null (because the parent
> record was deleted) does the attempt to obtain the
> cursor fail? ie does valentina effectively lock the
> record against write attempts while it is setting the
> ObjectPtr to null?

This question related to multi-threading, right?

Well, 1.x engine will not return until ObjectPtr finish job. So cursor will
never catch issue you are asking for.

Reverse case may happens. Cursor lock records for WRITE. Now you try delete
parent record, it try modify LOCKED record of child table => exception.




-- 
Best regards,

Ruslan Zasukhin
VP Engineering and New Technology
Paradigma Software, Inc

Valentina - Joining Worlds of Information
http://www.paradigmasoft.com

[I feel the need: the need for speed]