a. Problem occurred when rolling back first transaction: Consider the given case where another transaction takes up the space generated by the deletion of a record by an uncommitted transaction. In case, if the first transaction needs to be rolled back, then The record deleted by the first transaction is restored. When the usual physical manner undo is performed with the old record values; The space that was reallocated to the new record by the second transaction would get overwritten by this undo...

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Answer 1

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Chapter 19, Problem 9PE

Explanation of Solution

a.

Problem occurred when rolling back first transaction:

Consider the given case where another transaction takes up the space generated by the deletion of a record by an uncommitted transaction.

In case, if the first transaction needs to be rolled back, then

The record deleted by the first transaction is restored.

When the usual physical manner undo is performed with the old record values;

The space that was reallocated to the new record by the second transaction would get overwritten by this undo...

Explanation of Solution

b.

Issues:

When page-level locking is used, this problem will not crop up because of the following reasons:

The free space gener...

Explanation of Solution

c.

Solving the problem:

In order to resolve the problem using tuple-locking the following methods are followed:

Defer the freeing up of space until a transaction commit.

Here, ensure that the space will be freed even when a system fails just after the commit.

For this, the log records are modified for including the information about the space being freed, which should have been performed after the commit.

In fact, all such operations can be performed as a transaction along generating their log records, followed by the post-commit log records...

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Check out a sample textbook solution

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Draw a level-0 diagram for this scenario: You are developing a new customer relationship management system for the BEC store, which rents out movies to customers. Customers will provide comments on new products, and request rental extensions and new products, each of which will be stored into the system and used by the manager for purchasing movies, extra copies, etc. Each month, one employee of BEC will select their favorite movie pick of that week, which will be stored in the system. The actual inventory information will be stored in the Entertainment Tracker system, and would be retrieved by this new system as and when necessary.

Draw a context diagram for this scenario: You are developing a new customer relationship Management system for the BEC store, which rents out movies to customers. Customers will provide comments on new products, and request rental extensions and new products, each of which will be stored into the system and used by the manager for purchasing movies, extra copies, etc. Each month, one employee of BEC will select their favorite movie pick of that week, which will be stored in. the system. The actual inventory information will be stored in the Entertainment Tracker system, and would be retrieved by this new system as and when necessary.

Write a complete Java program named FindSumAndAverage that performs the following tasks in 2-D array: Main Method: a. The main() method asks the user to provide the dimension n for a square matrix. A square matrix has an equal number of rows and columns. b. The main() method receives the value of n and calls the matrixSetUp() method that creates a square matrix of size n and populates it randomly with integers between 1 and 9. c. The main method then calls another method named printMatrix() to display the matrix in a matrix format. d. The main method also calls a method named findSumAndAverage() which: • Receives the generated matrix as input. • Calculates the sum of all elements in the matrix. • Calculates the average value of the elements in the matrix. • Stores these values (sum and average) in a single-dimensional array and returns this array • e. The main method prints the sum and average based on the result returned from findSumAndAverage()). Enter the dimension n for the square…

Answer 2

Expert Solution & Answer

Chapter 19, Problem 9PE

Explanation of Solution

a.

Problem occurred when rolling back first transaction:

Consider the given case where another transaction takes up the space generated by the deletion of a record by an uncommitted transaction.

In case, if the first transaction needs to be rolled back, then

The record deleted by the first transaction is restored.

When the usual physical manner undo is performed with the old record values;

The space that was reallocated to the new record by the second transaction would get overwritten by this undo...

Explanation of Solution

b.

Issues:

When page-level locking is used, this problem will not crop up because of the following reasons:

The free space gener...

Explanation of Solution

c.

Solving the problem:

In order to resolve the problem using tuple-locking the following methods are followed:

Defer the freeing up of space until a transaction commit.

Here, ensure that the space will be freed even when a system fails just after the commit.

For this, the log records are modified for including the information about the space being freed, which should have been performed after the commit.

In fact, all such operations can be performed as a transaction along generating their log records, followed by the post-commit log records...

Expert Solution & Answer

Want to see the full answer?

Check out a sample textbook solution

See solution

Answer 3

Expert Solution & Answer

Chapter 19, Problem 9PE

Explanation of Solution

a.

Problem occurred when rolling back first transaction:

Consider the given case where another transaction takes up the space generated by the deletion of a record by an uncommitted transaction.

In case, if the first transaction needs to be rolled back, then

The record deleted by the first transaction is restored.

When the usual physical manner undo is performed with the old record values;

The space that was reallocated to the new record by the second transaction would get overwritten by this undo...

Explanation of Solution

b.

Issues:

When page-level locking is used, this problem will not crop up because of the following reasons:

The free space gener...

Explanation of Solution

c.

Solving the problem:

In order to resolve the problem using tuple-locking the following methods are followed:

Defer the freeing up of space until a transaction commit.

Here, ensure that the space will be freed even when a system fails just after the commit.

For this, the log records are modified for including the information about the space being freed, which should have been performed after the commit.

In fact, all such operations can be performed as a transaction along generating their log records, followed by the post-commit log records...

Expert Solution & Answer

Want to see the full answer?

Check out a sample textbook solution

See solution

Answer 4

Expert Solution & Answer

Chapter 19, Problem 9PE

Explanation of Solution

a.

Problem occurred when rolling back first transaction:

Consider the given case where another transaction takes up the space generated by the deletion of a record by an uncommitted transaction.

In case, if the first transaction needs to be rolled back, then

The record deleted by the first transaction is restored.

When the usual physical manner undo is performed with the old record values;

The space that was reallocated to the new record by the second transaction would get overwritten by this undo...

Explanation of Solution

b.

Issues:

When page-level locking is used, this problem will not crop up because of the following reasons:

The free space gener...

Explanation of Solution

c.

Solving the problem:

In order to resolve the problem using tuple-locking the following methods are followed:

Defer the freeing up of space until a transaction commit.

Here, ensure that the space will be freed even when a system fails just after the commit.

For this, the log records are modified for including the information about the space being freed, which should have been performed after the commit.

In fact, all such operations can be performed as a transaction along generating their log records, followed by the post-commit log records...

Expert Solution & Answer

Want to see the full answer?

Check out a sample textbook solution

See solution

Answer 5

Expert Solution & Answer

Answer 6

Expert Solution & Answer

Answer 7

Chapter 19, Problem 9PE

Explanation of Solution

a.

Problem occurred when rolling back first transaction:

Consider the given case where another transaction takes up the space generated by the deletion of a record by an uncommitted transaction.

In case, if the first transaction needs to be rolled back, then

The record deleted by the first transaction is restored.

When the usual physical manner undo is performed with the old record values;

The space that was reallocated to the new record by the second transaction would get overwritten by this undo...

Explanation of Solution

b.

Issues:

When page-level locking is used, this problem will not crop up because of the following reasons:

The free space gener...

Explanation of Solution

c.

Solving the problem:

In order to resolve the problem using tuple-locking the following methods are followed:

Defer the freeing up of space until a transaction commit.

Here, ensure that the space will be freed even when a system fails just after the commit.

For this, the log records are modified for including the information about the space being freed, which should have been performed after the commit.

In fact, all such operations can be performed as a transaction along generating their log records, followed by the post-commit log records...

Answer 8

Chapter 19, Problem 9PE

Explanation of Solution

a.

Problem occurred when rolling back first transaction:

Consider the given case where another transaction takes up the space generated by the deletion of a record by an uncommitted transaction.

In case, if the first transaction needs to be rolled back, then

The record deleted by the first transaction is restored.

When the usual physical manner undo is performed with the old record values;

The space that was reallocated to the new record by the second transaction would get overwritten by this undo...

Answer 9

Chapter 19, Problem 9PE

Explanation of Solution

a.

Problem occurred when rolling back first transaction:

Consider the given case where another transaction takes up the space generated by the deletion of a record by an uncommitted transaction.

In case, if the first transaction needs to be rolled back, then

The record deleted by the first transaction is restored.

When the usual physical manner undo is performed with the old record values;

The space that was reallocated to the new record by the second transaction would get overwritten by this undo...

Answer 10

Explanation of Solution

b.

Issues:

When page-level locking is used, this problem will not crop up because of the following reasons:

The free space gener...

Answer 11

Explanation of Solution

b.

Issues:

When page-level locking is used, this problem will not crop up because of the following reasons:

The free space gener...

Answer 12

Explanation of Solution

c.

Solving the problem:

In order to resolve the problem using tuple-locking the following methods are followed:

Defer the freeing up of space until a transaction commit.

Here, ensure that the space will be freed even when a system fails just after the commit.

For this, the log records are modified for including the information about the space being freed, which should have been performed after the commit.

In fact, all such operations can be performed as a transaction along generating their log records, followed by the post-commit log records...

Answer 13

Explanation of Solution

c.

Solving the problem:

In order to resolve the problem using tuple-locking the following methods are followed:

Defer the freeing up of space until a transaction commit.

Here, ensure that the space will be freed even when a system fails just after the commit.

For this, the log records are modified for including the information about the space being freed, which should have been performed after the commit.

In fact, all such operations can be performed as a transaction along generating their log records, followed by the post-commit log records...

Answer 14

Expert Solution & Answer

Answer 15

Expert Solution & Answer

Answer 16

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Answer 17

Ch. 19 - Prob. 1PE Ch. 19 - Prob. 2PE Ch. 19 - Prob. 3PE Ch. 19 - Prob. 4PE Ch. 19 - Prob. 5PE Ch. 19 - Prob. 6PE Ch. 19 - Prob. 7PE Ch. 19 - Prob. 8PE Ch. 19 - Prob. 9PE Ch. 19 - Prob. 10PE

Explanation of Solution

Explanation of Solution

b. Issues: When page-level locking is used, this problem will not crop up because of the following reasons: The free space gener...

Explanation of Solution

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Chapter 19 Solutions

b.

Issues:

When page-level locking is used, this problem will not crop up because of the following reasons:

The free space gener...