The fi nal phase, called the write phase, either writes the modifi ed data into permanent
database and/or displays retrieved data to the user. In the write phase, the output list produced
by the transaction is broadcast to the “relevant” DMs as write messages. A DM is relevant if
it contains a physical copy of some logical data item that is referenced in the output list. The
updated data are written in SDD-1 database using a write-all approach. The atomicity of transac-
tions is preserved by using a specialized commit protocol that allows the commitment of transac-
tions in case of involved site failures.
The three-phase ...
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