Storing transactions (commit)

There are not much problems known while storing transactions. Also database correlation factor does not play a role in this phase. The main problem while storing a transaction is keeping the database consistent. Since the storing a transaction takes time (even though it is very short), the database becomes inconsistent for a few milliseconds (or longer). Thus, it has to be made sure, that during storing a transaction all updated database entries are locked (read). Otherwise, other processes running on the database might read inconsistent data.

This behavior has to be controlled by the DBMS. Moreover, the DBMS should support crash handling, i.e. a situation where the process terminates abnormally while storing the transaction (e.g. power blackout), e.g. by save-before-store strategy (save transaction somewhere before starting to store it) or others. Since this is, again, time consuming, some DBMS allow the application to enable "save transaction" features.