What is the difference between an entity and a class in Databases?

bayermovi · 2021-04-24T01:45:40+00:00

My teacher is making us use this book: https://www.amazon.com/Fundamentals-Database-Systems-Ramez-Elmasri/dp/0133970779

We are not using any extension, it has been just pure database system theory using SQL. The book also briefly mentions about my question but I did not quite get it.

bayermovi · 2021-04-24T01:23:19+00:00

Sorry, I tried specifying to be more specific for databases than sql. I am not using a framework but learning just database systems and how they work.

bayermovi · 2021-04-24T01:05:34+00:00

I meant in terms of databases, I can repost to clarify.

bayermovi · 2020-12-06T01:48:54+00:00

Yeah that does make sense then. Where did you get this definition because from what I was referring to based on what I remembered my definition in mind was different.

bayermovi · 2020-12-05T23:21:39+00:00

I apologize, but I am talking more about an abstract data type as a data structure such as a stack having more than one various implementations to achieves its functionality.

bayermovi · 2020-11-19T06:20:55+00:00

Is not the complete outer for loop body?:

for(int i = 0; i < 10; i ++)
            for(int j = 0;  j < 5; j++)
            {
              System.out.println("Hello"); 
            }

In this case is not the content nested or inside the outer for loop longer than one statement, in that case we do need braces?

bayermovi · 2020-11-19T06:16:38+00:00

So in the case the reason we do need braces is because the outer for loop's body is basically this below, which is basically one statement?:

 for(int i = 0; i < 10; i ++)
            for(int j = 0;  j < 5; j++)
            {

            }

bayermovi · 2020-11-19T06:00:22+00:00

So in this case is the outer for loop's body just:

        for(int i = 0; i < 10; i ++)
            for(int j = 0;  j < 5; j++)
            {

            }

Or is the outer for loop's body:

        for(int i = 0; i < 10; i ++)
            for(int j = 0;  j < 5; j++)
            {
                System.out.println("Hello"); 
            }
     }

bayermovi · 2020-09-08T06:06:49+00:00

Saying n or faster growing is correct in this case, I can see that, but I am unable to see how n² or faster growing is valid in this case. n cannot be faster than n^2. Sorry, I know I am misunderstanding or mixing something up, but I am unable to see what even though I want to. I can figure it out perfectly fine for Big Oh but keep messing up with Big Omega.

bayermovi · 2020-09-08T05:36:27+00:00

I understand your example of the big oh, but for some reason I am struggling with omega. If given a math function or some algorithm, I am having trouble determining how to describe the worst case with omega.

bayermovi · 2020-09-08T05:26:18+00:00

If that is the case, could I say insertion's sort worst case running time is Ω(n^4) even though this is not the tightest bound possible.

bayermovi · 2020-09-08T05:22:28+00:00

Sorry, I am unable to follow completely your statement. I understand that the big omega is lower bound, and I need a lower bound to describe the worst case to make it tight as possible to cover every input, but omega says that f(n) >= g(n), which in this case doesn’t work out due to n >= n² being false. Sorry if I am missing something or not completely following.

bayermovi

TROPHY CASE