Hi Ricky,
on SQL Server is possible lock a record ( pessimistic mode ),
but for do this,
you need have a
- transaction open
- use SET LOCK_TIMEOUT
- lock the primary key index with a Select hints
- build a lock handling engine on VFP
The only hard point is this:
SQL Server have a lock escalation ( for reduce the memory overhead ),
this is out of programming control;
if SQL apply a lock escalation, you can give a lock on rows that you donnot
lock, this characteristic reduces the sharing, but it does not create incoherence problems.
Is complex, but is possible ( i implement it ).
Another way is this:
build a ##MUTEX_TABLE, and implement the rows locking using
READUNCOMMITTED, READPAST, READCOMMITTED hints on this global temp table;
you need apply the mutex concept to this table.
This is more simple, but you need to implement all the lock mechanism:
tons of triggers !!
Fabio
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