Parte 1

1. What is a resource record?

Resource Records define data types in the Domain Name System (DNS)

2. What is the difference between a recursive and a iterative query in DNS? When is each type of query used?

Recursive DNS queries occur when a DNS client requests Information from a DNS server that is set to query subsequent DNS servers until A definitive answer is returned to the client.

In customer requests and fordwarded

Iterative DNS queries are ones in which a DNS server is Queried and returns an answer without querying other DNS servers

In name servers

3. Some computers are given a different IP address each time They connect to the internet.An internet service provider (ISP) can use a few IP addresses to serve many  customers That way….... Continue reading "Connection" »

types of network: depend on the geographical size

Adware is a type of free software supported by advertisements that showup in Pop-up windows or on a toolbar on your computer or browser. Mostadware is Annoying, but safe. But some is used to gather your personal information, track The websites you visit or even record your keystrokes. How to Recognize adware Your device is probably infected with adware if you Start seeing ads popping up in applications where you hadn't seen them before. Pop-ups can also show up on your computer's desktop even when you're not Browsing the Internet. Also, your browser's homepage may have been Changed. How to remove adware Before removing adware from your Device, be sure to back up any important files that you want to keep safe. Then Use antivirus or adware removal... Continue reading "pene" »

1.A) f(n) = 10 n^2 log (n^10) + n log (n^5) => o(n^2)    1.B) f(n) = 2^100 n^4 + n^3 => o (n^4)

2.A) 2 nested for inside for =>  n [n+n] = 2n^2

2.B) no. Of primitive operations (1 comparison & 1 return tot=2), 1 for println, (1 for division & 1 for recursive call) => running time is o(n)

2.C) Assignment 1, comparison 1, division 1 & assignment 1 tot=2, addition 1 & assignment 1 tot= 2 (while n), return 1 => running time o(n)

3.A) c2g(n) above f(n) and c1g(n) under f(n)

for constant c1 and no f(n) is omega (g(n)) for every n>=no || for constant c2 and no f(n) is O(g(n)) for every n>=no then f(n) = theta (g(n))

3.B) cg(n) above f(n) >> for constant c and no   f(n)= O(g(n))

3.C) cg(n) under f(n) &... Continue reading "Algorithms" »

What is an array? - An Array is an ordered collection of items. 

What is the following Array -   int[] arr = new int[3]; - One-dimensional array
What is the output of the following Java program? - No output and there is an error when the program is Compiled.

if ((i != j) && (a[i] == a[j])) – -1 when lonely false, works

if (a[i] == a[j]) { - always returns -1 (fails)

if break removed, run slower

2 3  return x + secretMethod(x, n - 1);  -   4

2 3 return x * secretMethod(x, n - 1); -   0

4 return x * secretMethod(x - 2);   -   8

insertion sort, but bubbles all prev for each element

Selection sort – find next smallest and swap into n element. N+1.

Radix sort – buckets. Start with LSB.

5 7         System.Out.Println(node.

Introducing networks

A network is created when more than one device is connected together. A network can be a small collection of computers connected within a building (eg a school, business or home) or it can be a wide collection of computers connected around the world.

Advantages

-Communication – it is easy (and often free) to communicate using email, text messages, voice calls and video calls.

-Roaming – if information is stored on a network, it means users are not fixed to one place. They can use computers anywhere in the world to access their information.

-Sharing information – it is easy to share files and information over a network. Music and video files, for instance, can be stored on one device and shared across many computers, so

Hardware: physical equipment used to process, store or transmit computer programs or data.

Module 3 Quiz

1.Structured Query Language (SQL) is considered a procedural language. False
2.PL/SQL fully supports SQL data types. True
3. The term anonymous blocks refers to blocks of code that are not stored for reuse and do not exist after being executed. True
4.The BEGIN section of a PL/SQL block contains code that creates variables, cursors, and types. True
5. Assignment statements are used to put or change the values of variables. True
6. A disadvantage of using the %TYPE attribute is that there is a slight performance hit in that the database server must look up the data type from the data dictionary. True
7. A collection is a data type that can store multiple values of different data types as one unit. False
8. A scalar variable can hold multiple... Continue reading "Constants pi type p decimals 2 value '3.1'" »