Many applications need to generate sequence numbers for each transaction. a. If a sequence counter is locked

Question:

Many applications need to generate sequence numbers for each transaction.

a. If a sequence counter is locked in two-phase manner, it can become a concurrency bottleneck. Explain why this may be the case.

b. Many database systems support built-in sequence counters that are not locked in two-phase manner; when a transaction requests a sequence number, the counter is locked, incremented and unlocked.

i. Explain how such counters can improve concurrency.

ii. Explain why there may be gaps in the sequence numbers belonging to the final set of committed transactions.

Fantastic news! We've Found the answer you've been seeking!

Step by Step Answer:

Related Book For book-img-for-question

Database System Concepts

ISBN: 9780078022159

7th Edition

Authors: Abraham Silberschatz, Henry F. Korth, S. Sudarshan

See More Books

Question Posted: Jun 13, 2022 06:41 AM

See More Questions

For each transaction a through f, identify its impact on the accounting equation (select from 1 through 6 below). _____ a. The company pays cash toward an account payable. _____ b. The company...
When rights such as those in this case become more valuable as a result of new technology, should the law be changed to redistribute the economic benefit of those rights? Why or why not?
How and why did database management systems become the organizational data management standard in organizations? Discuss some of the advantages of the database approach over the file-system approach.
Assume that a CPA has just received a new audit client. The client will be the firms largest audit client, and the firm will have to hire one new staff member to staff the engagement. The fees will...
The results from an analysis of the table entries cause us to reject the claim that nausea is independent of whether the subject took a placebo or Chantix. Can we conclude that getting nausea is...
For the characteristic equation s3+ 9s2 + 26s + K = 0, use the Routh-Hurwitz criterion to compute the range of K values required so that the dominant time constant is no larger than 1/2.
Review a document related to risk management, such as Microsofts Security Risk Management Guide, which is available from the companion Web site for this text. Does this guide address most of the...
Metropolitan Edison Company owned and operated two nuclear fueled power plants at Three Mile Island near Harrisburg, Pennsylvania. Both power plants were licensed by the NRC after extensive...
The St. Lucia Blood Bank, a private charity partly supported by government grants, is located on the Caribbean island of St. Lucia. The blood bank has just finished its operations for September,...
Starting teachers salaries (in equivalent U.S. dollars) for upper secondary education in selected countries are listed below. Which set of data is more variable? (The U.S. average starting salary at...
Suppose you are given a relation r(a, b, c). a. Give an example of a situation under which the performance of equality selection queries on attribute a can be greatly affected by how r is clustered....
Find out all performance information your favorite database system provides. Look for at least the following: what queries are currently executing or executed recently, what resources each of them...
Based upon the data presented in Exercise 2-4, prepare an unadjusted trial balance, listing the accounts in their proper order.
Convex Productions produces full-length motion pictures for distribution worldwide. Convex has just purchased the rights to a movie script entitled Native Sun, which it intends to develop as its next...
You are visiting the Engineering Office of Denton Hospital, as part of a consulting project. You notice some charts on one wall which look familiar to you: One of the employees notices you reading...
Richmond Clinic has obtained the following estimates for its costs of debt and equity at different capital structures: What is the firms optimal capital structure? (Hint: Calculate its corporate cost...
Suppose a sample yields estimates $\widehat{\theta}_{1}=5, \widehat{\theta}_{2}=3$, se $\left[\widehat{\theta}_{1} ight]=2$, and se $\left[\widehat{\theta}_{2} ight]=1$ and the correlation...
Helium expands in a nozzle from $0.8 \mathrm{MPa}, 500 \mathrm{~K}$, and negligible velocity to $0.1 \mathrm{MPa}$. Calculate the throat and exit areas for a mass flow rate of \(0.34 \mathrm{~kg}...
The annual earnings (in dollars) of 32 randomly selected magnetic resonance imaging technologists. Use the data set to (a) Find the sample mean, (b) Find the sample standard deviation, and (c)...
What is the ideal number of children to have? This question was asked on the Sullivan Statistics Survey I. Draw a dot plot of the variable Children from theSullivanStatsSurveyI data set at...
Explain the purpose of the checkpoint mechanism. How often should checkpoints be performed? How does the frequency of checkpoints affect System performance when no failure occurs The time it takes...
When the system recovers from a crash, it constructs an undo-list and a redo-list. Explainwhy log records for transactions on the undolist must be processed in reverse order, while those log records...
Compare the shadow-paging recovery scheme with the log-based recovery schemes in terms of ease of implementation and overhead cost.
1. Compute the productivity profiles for each year. If required, round your answers to two decimal places. 2a. Did productivity improve? 2b. Explain why or why not
Explain: An office building is renting for $10/sf, with 50,000 total leasable square feet. Office buildings in the area are selling for cap rates of 5.5%. What information do you have and what are...
Practicum Co. pad $1.2 million for an 80% interest in the common stock of Sarong Co. Practicum had no previous equity interest in Sarong. On the acquisition date, Sarong's identifiable net assets had...

Many applications need to generate sequence numbers for each transaction. a. If a sequence counter is locked

Question:

Step by Step Answer:

a If a sequence counter is locked in twophase manner it can become a concurrency bott...View the full answer

Database System Concepts

Students also viewed these Computer science questions