TABLE

So here we have the object user and we have a table.
And when we create a table, we give it a name. That name is of that object.

Each table has a name and that name relates to the concept of the data we're going to store.

Column

And then when we look at a table, we can see that we have these things at the top called columns. And each column represents a specific type of data.

table has a name and a table has columns that store specific types of data.

Row

and each and every row is a singular piece of data.
It represents one single piece of data for that table.
That is one piece of data and that data is split up into columns that represent each and every piece.

Table vs Excel

We are actually saying what we want to store in each and every column where in Excel the columns are generic, they're pre named(A,B,C...)

a table has much more nuance.
What do I mean by nuance?
There's a lot more details here.
We're very, very, very specific in what we want to store and how we want to store it.

DEGREE

But what would we call the collection of all the columns?
Well, that's what we would call the degree.
Or you could say the degree of the relation is I'd first name, last name, sex and date of birth.
Nevertheless, it's the term that we used to call out the collection of columns and each and every column stores a specific type of data.

DOMAIN / CONSTRAINT

Well, when we talk about what a column can store, we call that the domain or the constraint we're seeing, OK, in date of birth, we can only store dates.
So we're saying and date of birth only put dates and the same we could say for sex only put one singular letter.

That's what we call domain. It's the constraint(=restriction) of the data.

ATTRIBUTES

And another way of talking about columns is saying, well, my table has these attributes with these constraints.

TUPLES/ROWS

Touple is one singular row of data tuples are multiple rows of data.
And so what's important to know here is that each and every couple follows the column constraints,

CARDINALITY

We call that the cardinality or the collection of rows or tuples.

정리

Every table has a column, multiple columns, or you can have a singular column, but mostly you'll have multiple columns and so every table has columns.

Columns are also called attributes, and the collection of columns is called the Degree.
And each and every column may or may not enforce a specific type of data to be saved in it.
We call these constraints or the domain of the attribute attribute domains, so to speak.

Relation

PRIMARY KEY

something that uniquely identifies your data.
Well, uniquely identifying each and every piece of data means that we can now know for certain the

FOREIGN KEY

for saying, well, if the primary key is uniquely identifying my data in place, if I am going to reference data from somewhere else, well, I'm going to reference it by that primary key.
And the way we do this is by injecting(=put it) a column, there is a new column in this table in the sole purpose of this column is to manage that relationship is to say, hey, well, Mo Is managed by anyone, so a foreign key references the primary key of a different table.

A foreign key is a key that will reference the primary key, the unique identifier of a different table, therefore allowing a relationship to be formed that is solidified in stone.

OLTP VS OLAP

OLTP (=Online Transaction Processing)

OLTP is driving the day to day business, the transactions(bussiness) that we do, the back and forth. And all they do all day DB is store and categorize this data in that relational model.

OLAP(Online Analytical Processing)

What is valuable about that data?
every action you do that is used somewhere, somehow to drive analytics that drives a company to make decisions.

That data that you need and OLAP online analytical processing is driving those future decisions.