Sukhen wrote:

>>>update never fails but it fails in insert query. loop run in a single connection with a new datarows in same query.

I answered:

>>I think it is about time to show us some code (not all). Could it be that another transaction not visible to your current
>>transaction has inserted a row that creates a lock conflict with your insert and that your code repeatedly tries (and fails)
>>to insert? Or that it is a real deadlock, where one transaction first successfully updates record A, then fails on record B,
>>whereas another transaction has successfully updated record B and fails on record A?
>>
>>Typically, there would be no problems on INSERT, whereas UPDATE could create problems. Getting the problem on INSERT, I'd say
>>indicates some kind of lock conflict which means that you have some UNIQUE field or constraint or don't use generators to
>>populate your primary key.

Sukhen answered:

>is it could be any buffersize/memmroy issue. please, suggest if it is how to check it in firebird
>please, somebody help me out

I didn't answer because I know nothing about buffersize/memory issues with Firebird (other than knowing that buffersize/memory very rarely causes problems with Firebird itself, don't know about the components you use in VB to connect to Firebird).

Normally, INSERTs would never fail. When they fail, that indicate some duplicate in a unique index or constraint or primary key (though that ought to give an error rather than be time consuming). Or it could possibly be an infinite loop. INSERTs can be slow, depending on complexity. Show us some code, I'm particularly interested in the INSERT that fails and the table definitions for the tables that the INSERT refers to.

Set