Il 09/05/2019 18:01, Thomas Steinmaurer ts@...
[firebird-support] ha scritto:

>> I have a program that uses Firebird 2.1. Most installation use the
>> embedded version so I prefer to stick with 2.1 since it does all I need.
>>
>> I have a question about transactions: if I start a transaction, I add or
>> modify some data, then the program gets an exception and it crashes,
>> what happens to the transaction?
>>
>> I was believing that if the program terminates without calling commit or
>> rollback, then the transaction is automatically rolled back.
>>
>> Now a customer had a problem that can be explained if the transaction is
>> not rolled back, but the data changes remained in the database even if
>> commit was not called because the program crashed before calling it.
>>
>> Can anybody explain if changed data in this situation remains in the
>> database of is it rolled back?
>
> Data changes, which did not get acknowledged by either COMMIT or COMMIT
> RETAINING should never get permanently persisted.
>
> Any chance that you are using your client access components in auto
> commit mode?
>
>

Thank you for your answer. I am using IBPP with C++ so auto commit
should not be a problem.

I made some research and I found this in the Firebird book:

"NOTE Calls from the client to COMMIT or to ROLLBACK are the only
possible ways to end a transaction. A failure to commit does not cause
the server to roll back the transaction."

On the other hand I made some tests using the debugger: I stopped the
program before committing the transaction and I did not find any
modified data in the database.

I am confused.