going to do a "System of management students"
- always wanted one!
Sorry, I could not resist, then in the case of:
I can't know Your personal preferences and style of teaching You are used to or think is most true or preferable, but in teaching, I often used the method of "visualization" of what is happening. Quite difficult to explain to someone who's never worked with networks, what is the IP4 package... but when I draw this visually, the perceptual quality is significantly improved.
Actually, what I'm this... Take a sheet of paper or canvas (paint, photoshop, etc.), program for drawing flowcharts, or software to create sketches or something like that and try to draw all of the tables/database objects and the relationships between them. Also, a similar feature exists in many program to work with the database (visualization of tables and their relationships). When You will be able to visually see and represent the objects - it is much easier to perceive what is happening.
An example of life - try to explain to someone what a table of a relational database... if you were to draw an analogy with a sheet from Excel in 95% of cases, the understanding comes almost instantly.
So I can say that the selection at the initial stage, PostgreSQL is not the best idea. PostgreSQL is a very cool database, if You really understand why You need it and why it is. That is, in cases when You have tight "MySQL-pants" and not enough scope for action and hundreds of unnecessary settings to tweak and tweak and enchanting number of options and possibilities most databases - PostgreSQL would be the optimal choice, in other cases, You will curse the world, developers and all things, are constantly faced with some difficulties, which sometimes may even seem silly (though, in 99% of cases it is not). For example, which is only the point that in PostgreSQL there is no "table engines", or not to swap the previously created columns in the table without completely rewriting the entire table, or a dozen indices (and which one to choose?!), against a much more meager amount in MySQL...
My students are often faced with similar problems, according to this, we came to this practice - base design and prototypically to MySQL, there is changing to blue in the face until it is verified do the right vector of development of the database, the code driven around... and then, the project is easily and naturally moved to PG, where he supplied some buns and Goodies PG level (those that MySQL-e no).
I recommend to You, as well as my students - first to design database in MySQL, we usually do this in the program HeidiSQL
(free), all very clearly and colorful. Break in Your code and the logic DB, and then, if you really can't wait to migrate to Postgres.
From personal experience, I can say that many choose PostgreSQL, because it(a) "cooler". It is not so, or not so... of the many projects on the PG we only put up one, there is a database amounts to many tens or hundreds of gigabytes, number of tables was close to a thousand, and the number of records in a particular table - the tens of millions. But even now I am working in support project, the volume of data exceeds 1TB, and all lived well on MySQL. According to this, if You choose PG exclusively for some ideological rather than technical reasons - think again.