Hello, W!

Monday, January 7, 2013, 2:33:30 AM, you wrote:

WO> Hello everybody, I have a question:

WO> - Transaction 510 inserts a row
WO> - Transaction 510 commit

ok, data committed.

WO> - Transaction 526 start
WO> - Transaction 526 updates the row inserted by transaction 510

well, row "locked" by update made by transaction 526.

WO> - Transaction 535 start
WO> - Transaction 535 updates the row inserted by transaction 510

no, transaction 535 will get error "deadlock", because
version created by transaction 526 is not committed or rolled back
yet.

WO> - Transaction 542 start
WO> - Transaction 542 updates the row inserted by transaction 510

NO. Same reason that I noted before.

WO> 1. Should be the order for the following commits: 526, 535, 542?

NO.

WO> 2. Or in some cases it could be 542, 535, 526?

NO.

WO> If the answer is 1. it means that if transaction 526 hangs up will avoid
WO> transactions 535 and 542 to finish. Am I right?

No transaction can overwrite version, created by any transaction that
modified some record and has not committed or rolled back changes.

--
Dmitry Kuzmenko, www.ib-aid.com