Answer:
A primary key is a special relational database table column (or combination of columns) designated to uniquely identify each table record. A primary key is used as a unique identifier to quickly parse data within the table. A table cannot have more than one primary key.
Primary Key.
Candidate Key.
Alternate Key.
Super Key.
Composite Key.
Foreign Key.
Unique Key.
In the relational model of databases, a primary key is a specific choice of a minimal set of attributes that uniquely specify a tuple in a relation. Informally, a primary key is "which attributes identify a record," and in simple cases constitute a single attribute: a unique ID.
Explanation:
The <DEL> or <Delete> key makes the first character AFTER the cursor
disappear, and everything after it then moves back one space to close up
the hole.
Example:
If I have this in my document ... Most trees are green.
And my cursor is after the 'a', like this: Most trees a|re green.
Now, if I hit the <delete> key, it deletes the
'r' after the cursor, and the hole closes up,
and the cursor stays where it is: Most trees a|e green.
Answer:
The answer is option (4) Maximize redundancy as normalization minimizes redundancy of data.
Explanation:
Normalization of databases leads to minimization of data redundancy in databases. It doesn't maximize data redundancy. Data redundancy leads to wastage of resources. Normalization of databases minimizes insertion anomolies. Normalization of databases minimizes deletion anomolies. Normalization of databases minimizes updation anomolies. So , the answer to the question is option (4) maximize redundancy.
Answer:
a) Time to live field
b) Destination
c) Yes, they have two ip addresses.
d) 128 bits
e) 32 hexadecimal digits
Explanation:
a) the time to live field (TTL) indicates how long a packet can survive in a network and whether the packet should be discarded. The TTL is filled to limit the number of packets passing through N routers.
b) When a large datagram is fragmented into multiple smaller datagrams, they are reassembled at the destination into a single large datagram before beung passed to the next layer.
c) Yes, each router has a unique IP address that can be used to identify it. Each router has two IP addresses, each assigned to the wide area network interface and the local area network interface.
d) IPv6 addresses are represented by eight our characters hexadecimal numbers. Each hexadecimal number have 16 bits making a total of 128 bits (8 × 16)
e) IPv6 address has 32 hexadecimal digits with 4 bits/hex digit
Answer:
The undo tool.
Explanation:
Microsoft Excel is a spreadsheet application developed by Microsoft, it is used for analysing data. It's worksheets are made up of columns and rows or fields and records.
There are different ways of entering data to a cell. Click on the cell and type the data, copy and paste to the target cell, double-click on the cell to correct data and click on a cell and press the spacebar key to clear the data.
Excel records the action of event, so when a mistake is made like deleting a crucial cell data value, the undo tool is used to recover the data, since it holds records of events. The redo tool is the reverse of the undo tool.
