to complete our theoretical preparation we will need to learn more database terminology this is
a necessary step that will help us when we start coding in SQL later let's go through the entire
process of creating a database assume our database containing customer cells data has not been set
up yet okay so imagine you are the shop owner and you realize you have been selling goods quite well
recently and you have more than a million rows of data what do you need then a database but you know
nothing about databases who do you call an SQL specialist no you need a database designer she
will be in charge of deciding how to organize the data into tables and how to set up the relations
between these tables this step is crucial if the database design is not perfect from the beginning
your system will be difficult to work with and wouldn't facilitate your business needs you will
have to start over again considering the time and data and money involved in the process you
want to avoid going back to point zero what do database designers actually do they plot
the entire database system on a canvas using a visualization tool there are two main ways to do
that one is drawing an entity relationship diagram an ER diagram for brief it looks
like this and as its name suggests the different figures represent different data entities and the
specific relationships we have between entities the connections between tables are indicated
with lines this way of representing databases is powerful and professional but it is complicated
we will not focus in depth on ER diagrams in this course but you should know they exist and refer to
the process of database design another form of representation of a database is the relational
schema this is an existing idea of how the database must be organized it is useful when
you are certain of the structure and organization of the database you would like to create more
precisely a relational schema would look like this it represents a table in the shape of a rectangle
the name of the tables at the top of the rectangle the column names are listed below all relational
schemas in a database form the database schema you can also see lines indicating how tables are
related in the database as you probably noticed we have some other features but we will leave their
explanation for the next lecture once the database design process is done the next step would be to
create the database to this moment it has been ideas planning abstract thinking and design at
this stage it would be correct to say SQL can be used to set up the database physically as opposed
to contriving it abstractly then you can enjoy the advantages of data manipulation it will allow you
to use your data set to extract business insights that aim to improve the performance and efficiency
of the business you are working for this process is interesting and practically the main part of
the course will be related to that remember well-thought-out databases that are carefully
designed and created are crucial prerequisites for data manipulation if you have done good work with
these steps we could write effective queries and navigate in a database rather quickly you
will often hear the term database management it comprises all these steps of business undertakes
to design create and manipulate its databases successfully finally database administration is
the most frequently encountered job amongst all a database administrator is the person providing
daily care and maintenance of a database her scope of responsibilities is narrower regarding the ones
carried out by a database manager but she is still indispensable for the database department of a
company this lecture allowed us to learn certain terms you will be using often when dealing with
a databases I can't wait to get to the next video where we will explain how meaningful a
relational schema can be for you to understand the functioning of a certain database see you there