Engineering, 17.03.2020 19:24 andyromero

Assuming that pessimistic locking with the two-phase locking protocol is being used with row-level lock granularity, create a chronological list of the locking, unlocking, and data manipulation activities that would occur during the complete processing of the transaction described in Problem 6b.

Answers: 1

Show answers

Answers

Answer from: emily0259

Explanation:

Pessimistic Locking:

In this locking scheme a record is locked immediately when the user is requested for the lock and it will lock the records until user finished with the execution. When the user is done with accessing the document, the locks can be removed or released either manually or using a timeout protocol and user needs either a direct connection to the database or any external transaction ID for using this lock.

Two-Phase Locking:

The implementation phase of a transaction is divided into three parts with the help of two-phase locking. In the initial part, when the transaction starts implementing, it pursues authorization for the lock requires. In the second part, the transaction obtains all the locks and finally the transaction cannot demand for the new locks as it releases all the acquired locks.

Two-Phase locking system divided into two phases:

Growing Phase

The transaction may attain the locks. The transaction may not release any locks.

Shrinking Phase

The transaction may release the locks. The transaction may not attain any of the locks.

Pessimistic Locking with Two-phase Locking, The chronological list of the locking, unlocking, and data manipulation activities that would occur during the complete processing of the above given transaction which is described in 6b is as follows:

Note: Refer the image attached

Assuming that pessimistic locking with the two-phase locking protocol is being used with row-level l

Answer from: Quest

the equation above shows how temperature f, measured in degrees fahrenheit, relates to a temperature c, measured in degrees celsius. based on the equation, which of the following must be true?

a temperature increase of 1 degree fahrenheit is equivalent to a temperature increase of

degree celsius.

a temperature increase of 1 degree celsius is equivalent to a temperature increase of 1.8 degrees fahrenheit.

a temperature increase of

degree fahrenheit is equivalent to a temperature increase of 1 degree celsius.

a) i only

b) ii only

c) iii only

d) i and ii only

Answer from: Quest

Ireally wish i could but i will do some research and when i find the answer i will come back to assist you ; )

Another question on Engineering

Engineering, 03.07.2019 15:10

If you were designing a bumper for a car, would you prefer it to exhibit elastic or plastic deformation? why? consider the functions of a bumper in both a minor "fender-bender" and a major collision.

Answers: 1

Answer

Engineering, 04.07.2019 18:10

At 12 noon, the count in a bacteria culture was 400; at 4: 00 pm the count was 1200 let p(t) denote the bacteria cou population growth law. find: (a) an expression for the bacteria count at any time t (b) the bacteria count at 10 am. (c) the time required for the bacteria count to reach 1800.

Answers: 1

Answer

Engineering, 04.07.2019 18:20

Water vapor initially at 10 bar and 400 °c is contained within a piston-cylinder assembly. the water lost heat to the surrounding according to isochoric (iso-volumetric) process until its temperature is 150 °c. the water is then condensed isothermally to saturated liquid. for the water as a system, calculate the work in kj/kg

Answers: 2

Answer

Engineering, 04.07.2019 19:20

Aseries piping system conveys methyl alcohol. the system consists of 70 m of 1- nominal pipe follow by 50 m of 2-nominal pipe, both schedule 40 commercial steel. the 1-nominal pipe contains 3 90° elbows (regular) anda fully open gate valve, all threaded. the pressure drop through the system is 150 kpa. determine the volume flow rate through the system that is horizontally laid.

Answers: 1

Answer

You know the right answer?

Assuming that pessimistic locking with the two-phase locking protocol is being used with row-level l...

Questions