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3 years ago

What is a foreign key and how does it provide referential integrity?

Computers and Technology

1 answer:

Step2247 [10]3 years ago

4 0

Answer:

By definition a foreign key of table A is a primary key of another table B, thereby establishing a link between them.

To provide referential integrity you can use these referential actions:

Cascade: If rows in table B are deleted, the matching foreign key columns in table A are deleted.

Set Null: If rows in table B are deleted, the matching foreign key columns in table A are set to null.

Set Default: If rows in table B are deleted, the matching foreign key columns in table A are set with the default value of the column.

Restrict: A value in table B cannot be deleted or updated while as it is referred to by a foreign key in table A.

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Which of the following is not true about network design?Group of answer choicesIn designing LAN networks, network designers tend

sergey [27]

Answer:

In designing LAN networks, network designers tend to design err on the side of providing for less capacity than what is currently necessary.

Explanation:

In designing LAN networks, network designers tend to design err on the side of providing for less capacity than what is currently necessary is not true about network design.

8 0

3 years ago

Any computer or device on a network that can be addressed on the local network is referred to as a:

Umnica [9.8K]

Any computer or device on a network that can be addressed on the local network is referred to as a: node.

5 0

3 years ago

List five characteristics of a series circuit

Paladinen [302]

1. The current is the same everywhere in the circuit. This means that wherever I try to measure
the current, I will obtain the same reading.
2. Each component has an individual Ohm's law Voltage Drop. This means that I can calculate
the voltage using Ohm's Law if I know the current through the component and the resistance.
3. Kirchoff's Voltage Law Applies. This means that the sum of all the voltage sources is equal to
the sum of all the voltage drops or
VS = V1 + V2 + V3 + . . . + VN
4. The total resistance in the circuit is equal to the sum of the individual resistances.
RT = R1 + R2 + R3 + . . . + RN
5. The sum of the power supplied by the source is equal to the sum of the power dissipated in
the components.
PT = P1 + P2 + P3 + . . . + PN

6 0

4 years ago

Which statement best justifies the use of a high-speed cache in a CPU?

crimeas [40]

Cache memory is a high-speed memory that stores the instructions and data that have been frequently accessed. It decreases the time it takes to decode the instructions stored in the instruction pipeline.

A. It decreases the time it takes to decode instructions stored in the instruction pipeline.

Explanation:

Whenever an instruction is invoked or some data is accessed, the CPU looks for it in the cache memory before accessing the main memory.

If the content is found in the cache memory, it accessed from there and then and hence the access time and decode time is reduced as there were no main memory lockups.

6 0

3 years ago

Select the characteristics of a Base Transceiver Station:

Andru [333]

Answer:

The correct answer to the following question is options A, B, and D.

Explanation:

Base Transceiver Station (BTS) is an apparatus that works wireless communication between the network and user equipment (UE - Mobile phones (handset), wireless network computers). Wireless technologies like wi-fi, GSM, CDMA, etc.

Some elements of BTS :

Radio base station
Tower/Mast
Duplexer
Transceiver unit (TRU)
Microwave

So the above are the elements of the BSA, then it also having the characteristics related to these elements like it definitely connects to a cell network, sends phone or mobile phone and microwave signals to cellular providers but it isn't able to send the signals to the recepients.

8 0

3 years ago