Kbase P17173: Is two-phase commit mandatory when databases on same PC are
| Autor |
Progress Software Corporation - Progress |
| Acesso |
Público |
| Publicação |
12/03/2003 |
|
Status: Unverified
GOAL:
Is two-phase commit mandatory when databases on same PC are updated with the same transaction?
FIX:
It is not strictly necessary to run Two-Phase Commit when updating two separate databases located on the same machine via a single transaction.
There are advantages to using a Two-phase commit even if the databases are on the same machine (which in itself reduces the risk). For instance, should a transaction fail to commit on one of the databases, a shutdown and rollback would have to be done on both databases in order to restore integrity. With Two-phase commit in place, if a transaction fails to commit on one of the databases, then the failed transaction would be stored in a limbo state but one which could eventually be resolved at a later time.
But with or without Two-Phase Commit, After-Imaging should be run. Thanks to the option "endtime" for the Roll Forward process you can synchronise the two databases after a problem has occurred on one of them; while having Two-Phase Commit on, you would use the option "endtrans" for roll forwarding.