Two-phase commit question

In Table 1, the rows for PrN and PrA show identical counts of log writes, forced log writes, and messages in the case of a normal (read-write) transaction. What exactly is PrA optimizing if it doesn't show up in the table?

Answers need only be a few sentences.

Turn in your answer on paper at the start of class. Be sure both your SUNet ID and your name are on the paper.

SCPD students may submit via SCPD before the start of class.