1answer.
Ask question
Login Signup
Ask question
All categories
  • English
  • Mathematics
  • Social Studies
  • Business
  • History
  • Health
  • Geography
  • Biology
  • Physics
  • Chemistry
  • Computers and Technology
  • Arts
  • World Languages
  • Spanish
  • French
  • German
  • Advanced Placement (AP)
  • SAT
  • Medicine
  • Law
  • Engineering
Lunna [17]
4 years ago
14

Why can a "group by" or "order by" clause be expensive to process? What is the difference between a where and having clause?

Computers and Technology
1 answer:
Zielflug [23.3K]4 years ago
8 0

Answer and Explanation:

Group by clause bunches every one of the information coming back from the question in the predetermined gatherings.  

Order by clause will arrange the information either in rising  or in dropping order depending on the section data or column data.  

It is certainly a lengthy from execution perspective.  

Envision that the quantity of columns returned by the question are millions and gathering and arranging information from this parcel takes bigger execution time.  

The procedure is a lot of equivalent to on the off chance that you are approached to arrange the precisely coordinating names in a populace measurements, it requires colossal measure of handling time to make sense of the precisely coordinating names and after that arranging them as needs be.

The distinction between where and having clause:

'Where' and having clause in SQL are utilized to indicate separating conditions.  

There is a little contrast between these two clause and is given as under:  

WHERE clause is utilized while getting data (lines or rows) from the table, and the information which clears the condition will only be considered into  the result set.

HAVING clause is later utilized to channel a data summary or gathered data.  

On the off chance that the two clauses show up in SQL question, where clause will execute at first and afterward having clause is executed on the groups that returns the group clause.

You might be interested in
Carl wants to add a new slide to his PowerPoint presentation. Which option should he use?
djverab [1.8K]

Answer:

C on edg

Explanation:

I just took the review

8 0
3 years ago
Read 2 more answers
1. Write a program that declares an array named alpha with 50 components of the type double. Initialize the array so that the fi
Aleksandr [31]

Answer:

Explanation:

1. Write a program that declares an array named alpha with 50 components of the type double. Initialize the array so that the first 25 components are equal to the square of the counter (or index) variable and the last 25 components are equal to three times the index variable.  

  double alpha[50];

   for (int i=0;i<25;i++)

   {

       alpha[i]=i*i;

       alpha[i+25]=(i+25)*3;

  }

2. Output the array so that exactly ten elements per line are printed.  

   for (int i=0;i<50;i++)

   {

       cout<<i+1<<". "<<alpha[i]<<" ";

       if (((i+1)%10)==0)

       {

           cout<<endl;

       }

   }

3. Run your program again, but this time change the code so that the array is filled with random numbers between 1 and 100.  

   double alpha[50];

   for (int i=0;i<50;i++)

   {

       alpha[i]=rand()%101;

   }

   for (int i=0;i<50;i++)

   {

       cout<<i+1<<". "<<alpha[i]<<" ";

       if (((i+1)%10)==0)

       {

           cout<<endl;

       }

   }

4. Write the code that computes and prints the average of elements of the array.  

   double alpha[50],temp=0;

   for (int i=0;i<50;i++)

   {

       alpha[i]=rand()%101;

       temp+=alpha[i];

   }

   cout<<"Average :"<<(temp/50);

5. Write the code that that prints out how many of the elements are EXACTLY equal to 100.

   double alpha[50],temp=0;

   for (int i=0;i<50;i++)

   {

       alpha[i]=rand()%101;

       if(alpha[i]==100)

       {

           temp++;

       }

   }

   cout<<"Elements Exacctly 100 :"<<temp;

Please note:  If you put  each of above code to the place below comment  it will run perfectly after compiling

#include <iostream>

using namespace std;

int main()

{

   // If you put  each of above code here it will run perfectly after compiling

   return 0;

}

8 0
3 years ago
Two cars A and B leave an intersection at the same time. Car A travels west at an average speed of x miles per hour and car B tr
drek231 [11]

Answer:

Here is the C++ program:

#include <iostream>  // to use input output functions

#include <cmath>  // to use math functions like sqrt()

#include <iomanip>  //to use setprecision method

using namespace std;   //to access objects like cin cout

int main ()  {  //start of main function

  double speedA;  //double type variable to store average speed of car A

  double speedB;  //double type variable to store average speed of car B

  int hour;  //int type variable to hold hour part of elapsed time

  int minutes;  //int type variable to hold minutes part of elapsed time

  double shortDistance;  // double type variable to store the result of shortest distance between car A and B

  double distanceA;  //stores the distance of carA

  double distanceB;  //stores the distance of carB

  double mins,hours;   //used to convert the elapsed time

cout << "Enter average speed of car A: " << endl;  //prompt user to enter the average speed of car A

cin >> speedA;   //reads the input value of average speed of car A from user

cout << "Enter average speed of car B: " << endl ;  //prompt user to enter the average speed of car B

cin >> speedB;   //reads the input value of average speed of car A from user

cout << "Enter elapsed time (in hours and minutes, separated by a space): " << endl;  //prompts user to enter elapsed time

cin>> hour >> minutes;    //reads elapsed time in hours and minutes

  mins = hour * 60;  //computes the minutes using value of hour

  hours = (minutes+mins)/60;     //computes hours using minutes and mins

distanceA = speedA * (hours);  // computes distance of car A

distanceB = speedB * (hours);   //computes distance of car B

   shortDistance =sqrt((distanceA * distanceA) + (distanceB * distanceB));   //computes shortest distance using formula √[(distanceA)² + (distanceB)²)]

cout << "The (shortest) distance between the cars is: "<<fixed<<setprecision(2)<<shortDistance;

//display the resultant value of shortDistance up to 2 decimal places

Explanation:

I will explain the program with an examples:

Let us suppose that the average speeds of cars are:

speedA = 70

speedB = 55

Elapsed time in hours and minutes:

hour = 2

minutes = 30

After taking these input values the program control moves to the statement:

mins = hour * 60;  

This becomes

mins = 2 * 60

mins = 120

Next

hours = (minutes+mins)/60;

hours = (30 + 120) / 60

         = 150/60

hours = 2.5

Now the next two statements compute distance of the cars:

distanceA = speedA * (hours);  

this becomes

distanceA = 70 * (2.5)

distanceA = 175

distanceB = speedB * (hours);

distanceB = 55 * (2.5)

distanceB = 137.5

Next the shortest distance between car A and car B is computed:

shortDistance = sqrt((distanceA * distanceA) + (distanceB * distanceB));

shortDistance = sqrt((175 * 175) + (137.5 * 137.5))

                        = sqrt(30625 + 18906.25)

                        = sqrt(49531.25)

                        =  222.556173

shortDistance =  222.56

 

Hence the output is:

The (shortest) distance between the cars is: 222.56        

3 0
3 years ago
Consider Ron’s budget. How much money does Ron have left over each month?
vladimir1956 [14]
What is Ron’s budget?
4 0
3 years ago
Read 2 more answers
In windows 10, what is the name of a program you can use to find a file or folder?
Anna007 [38]

Answer:

windows search explorer

3 0
3 years ago
Other questions:
  • Company A is setting up a network of mostly Windows machines. Which networking file system protocol would you recommend for maxi
    5·1 answer
  • To help determine which technology to use, Raul creates a table to help him compare the pros and cons of his choices. What part
    15·1 answer
  • Client computers cannot function unless they are connected to the network because they cannot access an operating system.
    7·1 answer
  • Rank these three account types in order of decreasing liquidity. Start by picking the most liquid account type first
    13·2 answers
  • What percent of the internet is the deep web?
    14·1 answer
  • What type of ransomware was developed to block the user from accessing the computer and encrypts all the files on the user's dev
    5·2 answers
  • The advancement in speed of transportation is attributed to invention of this device
    8·1 answer
  • What common variation of the Server Message Block (SMB) sharing protocol is considered to be a dialect of SMB?
    11·1 answer
  • If the value of score1 is 350 and the value of score2 is 210, what will be the value of result after the code segment is execute
    9·1 answer
  • Write l for law of enrtia,ll for law of Acceleration and lll for law of enteraction.
    15·1 answer
Add answer
Login
Not registered? Fast signup
Signup
Login Signup
Ask question!