Skip to content Skip to navigation

Connexions

You are here: Home » Content » Exercise 8-Transactions Management, Concurrency Control

Navigation

Lenses

What is a lens?

Definition of a lens

Lenses

A lens is a custom view of the content in the repository. You can think of it as a fancy kind of list that will let you see content through the eyes of organizations and people you trust.

What is in a lens?

Lens makers point to materials (modules and collections), creating a guide that includes their own comments and descriptive tags about the content.

Who can create a lens?

Any individual member, a community, or a respected organization.

What are tags? tag icon

Tags are descriptors added by lens makers to help label content, attaching a vocabulary that is meaningful in the context of the lens.

This content is ...

Affiliated with (What does "Affiliated with" mean?)

This content is either by members of the organizations listed or about topics related to the organizations listed. Click each link to see a list of all content affiliated with the organization.
  • VOCW

    This module is included inLens: Vietnam OpenCourseWare's Lens
    By: Vietnam OpenCourseWare

    Click the "VOCW" link to see all content affiliated with them.

Recently Viewed

This feature requires Javascript to be enabled.
 

Exercise 8-Transactions Management, Concurrency Control

Module by: Nguyen Kim Anh. E-mail the author

Exercise 1

Draw the precedence graph for the following schedule:

Figure 1
Figure 1 (graphics1.png)

Exercise 2

(Based on Ramakrishnan, ex.17.2)

Consider the following incomplete schedule S:

Figure 2
Figure 2 (graphics2.png)
  • Determine (by using a precedence graph) whether the schedule is serializable
  • Modify S to create a complete schedule that is conflict-serializable

Exercise 3

(Based on Ramakrishnan, ex.17.3)

For each of the following schedules, draw the precedence graph for it and state whether it is conflict-serializable and/or view-serializable. If you cannot decide whether a schedule belongs to either class, explain briefly. The actions are listed in the order they are scheduled, and prefixed with the transaction name.

  • T1:R(X) T2:R(Y) T3:W(X) T2:R(X) T1:R(Y)
  • T1:R(X) T1:R(Y) T1:W(X) T2:R(Y) T3:W(Y) T1:W(X) T2:R(Y)
  • T1:R(X) T2:W(X) T1:W(X) T3:W(X)

Exercise 4

Consider the following two transactions:

Figure 3
Figure 3 (graphics3.png)
  • Write versions of the above two transactions that use two-phase locking.
  • Is there a non-serial schedule for T1 and T2 that is serializable? Why?

Content actions

Download module as:

PDF | EPUB (?)

What is an EPUB file?

EPUB is an electronic book format that can be read on a variety of mobile devices.

Downloading to a reading device

For detailed instructions on how to download this content's EPUB to your specific device, click the "(?)" link.

| More downloads ...

Add module to:

My Favorites (?)

'My Favorites' is a special kind of lens which you can use to bookmark modules and collections. 'My Favorites' can only be seen by you, and collections saved in 'My Favorites' can remember the last module you were on. You need an account to use 'My Favorites'.

| A lens I own (?)

Definition of a lens

Lenses

A lens is a custom view of the content in the repository. You can think of it as a fancy kind of list that will let you see content through the eyes of organizations and people you trust.

What is in a lens?

Lens makers point to materials (modules and collections), creating a guide that includes their own comments and descriptive tags about the content.

Who can create a lens?

Any individual member, a community, or a respected organization.

What are tags? tag icon

Tags are descriptors added by lens makers to help label content, attaching a vocabulary that is meaningful in the context of the lens.

| External bookmarks