A checkpoint log record indicates that a log record and its modified data has been written to stable storage and that the transaction need not to be redone in case of a system crash. Obviously, the more often checkpoints are performed, the less likely it is that redundant updates will have to be perRead more
A checkpoint log record indicates that a log record and its modified data has been written to stable storage and that the transaction need not to be redone in case of a system crash. Obviously, the more often checkpoints are performed, the less likely it is that redundant updates will have to be performed during the recovery process.
• System performance when no failure occurs-If no failures occur, the system must incur the cost of performing checkpoints that are essentially unnecessary. In this situation, performing checkpoints less often will lead to better system performance.
• The time it takes to recover from a system crash-The existence of a checkpoint record means that an operation will not have to be redone during system recovery. In this situation, the more often checkpoints were performed, the faster the recovery time is from a system crash.
•The time it takes to recover from a disk crash-The existence of a checkpoint record means that an operation will not have to be redone during system recovery. In this situation, the more often checkpoints were performed, the faster the recovery time is from a disk crash.
When (2,4) is deleted. Since C is a foreign key referring A with delete on cascade, all entries with value 2 in C must be deleted. So (5, 2) and (7, 2) are deleted. As a result of this 5 and 7 are deleted from A which causes (9, 5) to be deleted.
When (2,4) is deleted. Since C is a foreign key referring A with delete on cascade, all entries with value 2 in C must be deleted. So (5, 2) and (7, 2) are deleted. As a result of this 5 and 7 are deleted from A which causes (9, 5) to be deleted.
CREATE OR REPLACE PROCEDURE E_bill(unit in number,net out number) is BEGIN --drop procedure E_bill --for first 100 unit :RS 5 per unit if (unit between 0 and 100) then . . . . . . . . TAP ON ATTACHMENT BUTTON FOR ANSWER:
CREATE OR REPLACE PROCEDURE E_bill(unit in number,net out number) is
QUESTION: Design a combinational circuit using NOR gates with three inputs, x, y, and z, and three outputs, A, B, and C. When the binary input is 0, 1, 2, or 3, the binary output is one greater than the input. When the binary input is 4, 5, 6, or 7, the binary output is two less than the input. ANSWRead more
QUESTION:
Design a combinational circuit using NOR gates with three inputs, x, y, and z, and three outputs, A, B, and C. When the binary input is 0, 1, 2, or 3, the binary output is one greater than the input. When the binary input is 4, 5, 6, or 7, the binary output is two less than the input.
ANSWER IN ATTACHMENT JUST TAP ON ATTACHMENT BUTTON:
Two transactions T1 and T2 are given as: T1: r1(X) w1(X)r1(Y)w1(Y) T2 : r2(Y)w2(Y)r2(Z)w2(Z) where ri(V) denotes a read operation by transaction Ti on a variable V and wi(V) denotes a write operation by transaction Ti on a variable V. Calculate The total number of conflict serializable schedules that can be formed by T1 and T2
Two transactions T1 and T2 are given as: T1: r1(X) w1(X)r1(Y)w1(Y) T2 : r2(Y)w2(Y)r2(Z)w2(Z) . . . . . . .. ANSWER :
Two transactions T1 and T2 are given as:
T1: r1(X) w1(X)r1(Y)w1(Y)
T2 : r2(Y)w2(Y)r2(Z)w2(Z)
. . . . . . ..
ANSWER :
See lessState the purpose of the checkpoint mechanism. How often should checkpoints be performed? How does the frequency of checkpoints affect. a. System performance when no failure occurs
A checkpoint log record indicates that a log record and its modified data has been written to stable storage and that the transaction need not to be redone in case of a system crash. Obviously, the more often checkpoints are performed, the less likely it is that redundant updates will have to be perRead more
The following table has two attributes A and C where A is the primary key and C is the foreign key referencing A with on-delete cascade. A C —– 2 4 3 4 4 3 5 2 7 2 9 5 6 4 The set of all tuples that must be additionally deleted to preserve referential integrity when the tuple (2,4) is deleted
When (2,4) is deleted. Since C is a foreign key referring A with delete on cascade, all entries with value 2 in C must be deleted. So (5, 2) and (7, 2) are deleted. As a result of this 5 and 7 are deleted from A which causes (9, 5) to be deleted.
calculate electricity bill- dbms
CREATE OR REPLACE PROCEDURE E_bill(unit in number,net out number) is BEGIN --drop procedure E_bill --for first 100 unit :RS 5 per unit if (unit between 0 and 100) then . . . . . . . . TAP ON ATTACHMENT BUTTON FOR ANSWER:
CREATE OR REPLACE PROCEDURE E_bill(unit in number,net out number) is
BEGIN
–drop procedure E_bill
–for first 100 unit :RS 5 per unit
if (unit between 0 and 100) then . . . . . . . .
TAP ON ATTACHMENT BUTTON FOR ANSWER:
See lessCombination circuit using nor gate
QUESTION: Design a combinational circuit using NOR gates with three inputs, x, y, and z, and three outputs, A, B, and C. When the binary input is 0, 1, 2, or 3, the binary output is one greater than the input. When the binary input is 4, 5, 6, or 7, the binary output is two less than the input. ANSWRead more
QUESTION:
Design a combinational circuit using NOR gates with three inputs, x, y, and z, and three outputs, A, B, and C. When the binary input is 0, 1, 2, or 3, the binary output is one greater than the input. When the binary input is 4, 5, 6, or 7, the binary output is two less than the input.
ANSWER IN ATTACHMENT JUST TAP ON ATTACHMENT BUTTON:
See lessCreate a package which includes a function to return a square of a number if it is positive else return an error message to the user.
create or replace package Square as function cal(n in number) return number; . . . . . . . FULL ANSWER IS IN THE ATTACHMENT:
create or replace package Square as
function cal(n in number) return number;
. . . . . . .
FULL ANSWER IS IN THE ATTACHMENT:
See less