Explain why a cohort does not have to force an abort record to the log during the two-phase commit protocol.

What will be an ideal response?


The cohort might decide independently to abort (no prepare record is forced in this case) but crashes before the abort record it writes is durable. The coordinator will decide abort whether or not an vote message is received. The standard recovery procedures at the cohort site will cause the subtransaction to be aborted independent of whether an abort record is found.
The other case which causes an abort record to be written is if the cohort votes ready but receives an abort message from the coordinator. If the cohort crashes before the abort record is durable, the presumed abort property will result in the subtransaction being aborted anyway.

Computer Science & Information Technology

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When a reference variable is passed as an argument to a method __________.

a. a copy of the variable's value is passed into the method's parameter b. the method has access to the object that the variable references c. the method becomes a static method d. the program terminates

Computer Science & Information Technology

What control features will you use in the input screens to aid in data entry? Give a specific example of how you will use at least eight different control features in the design of the user interface.

What will be an ideal response?

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To execute a function, you must use a function ____________________.

Fill in the blank(s) with the appropriate word(s).

Computer Science & Information Technology

Match each activity with the most appropriate website.

A. Twitter B. YouTube C. Instagram D. Facebook

Computer Science & Information Technology