CubeSQL connection lost before commit

Databases
1

I know maybe I should write this straight to Marco at SQLabs, but I thought posting it here maybe I get a faster response…

The question is… What happens if my app crashes or gets an exception after a ‘begin transaction’ was done but before commiting it ?

Will it lock the DB ? How should I protect from this scenario ?

(Maybe just throw a commit in case of an unhandled exception ??)

Thanks
Roman

2

my understanding, it that is all in a journal file and if it “crashs” that file vanishes and it is as if nothing happened
but when the transaction completes, that journal file is “commited”

3

This would be easy to test. Start a transaction, kill your app running in debug mode, see what happens.

4

But I have code in the unhandled exception handler, so the app does not vanish if an unhandled exception occurs… it just cuts the process it was doing…

I think have read that uncommited write operations DO lock the db…

I’ll give it a try…

5

but they are not uncommited writes… you haven’t written them yet… thats the purpose of “transaction”

6

Once you “BEGIN TRANSACTION”, the db will be locked on CubeSQL for other writers, as there can be only 1 concurrent writer.
So if you handle exceptions, you’ll have to “ROLLBACK” or “COMMIT”.
Another way of “unlocking” is of course to close the connection (or let the database-object go out of scope so that it closes / or quit the application entirely).

try BEGIN TRANSACTION 'all ok COMMIT catch error 'we don't want to commit this unfinished transaction ROLLBACK end try