The quorum consensus replication algorithm requires that the timestamps of transactions be consistent with their commit order. In the absence of synchronized clocks, this requirement is not easily met. Propose an alternate algorithm for tagging replicas that can be used with quorum consensus. (Hint: Instead of assigning timestamps to transactions, assign version numbers to individual replicas.)
What will be an ideal response?
When an item is created, each replica is assigned the version number 0. When a transaction writes a new value to an item the new value of the version number of all the replicas in the set is one more than the maximum of all the old version numbers
in the set. Since read and write quorums intersect all write quorums, the replica with the maximum version number in any read quorum must have the most recent value of the item.
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Match each term with the appropriate definition
I. Split Form A. A control that is linked to a record source II. Multiple Items B. The underlying table or query that provides the fields for the form III. Record Source C. A control not linked to a record source, used to label form objects IV. Unbound D. A customizable form that displays multiple records from a source table or query in a datasheet format V. Bound E. Creates a customizable form displaying the record source in two views at the same time
List nodes normally are not necessarily stored in contiguous memory. Rather, they’re ________ contiguous.
a. physically b. approximately c. comparably d. logically