Not so long ago, the word "atom" referred to a thing that could not be split any further. Despite having discovered that atoms themselves are made up of even smaller particles, the term continues to retain its original meaning. With respect to relational databases, Atomicity means that operati...
Atomicity is particularly important to mitigate damage in case of database server crashes. If a non-volatile database crashes in the middle of a transaction, all changes done will be discarded or rolled back to avoid sending partial results to the production database. Consistency Consistency is a...
For historic MVCC snapshots, the meaning is inverted, i.e. * it contains *committed* transactions between xmin and xmax. * * note: all ids in xip[] satisfy xmin <= xip[i] < xmax */ TransactionId *xip; uint32 xcnt; /* # of xact ids in xip[] */ ... } A snapshot...