Here is some vanilla SQL:
CREATE TABLE RoomTypes
(
RoomType VARCHAR(12) NOT NULL,
UNIQUE (RoomType)
);
CREATE TABLE Zones
(
Zone VARCHAR(10) NOT NULL,
UNIQUE (Zone)
);
CREATE TABLE Rooms
(
RoomType VARCHAR(12) NOT NULL,
Zone VARCHAR(10) NOT NULL,
Name VARCHAR(30) NOT NULL,
UNIQUE (RoomType, Zone, Name),
FOREIGN KEY (RoomType) REFERENCES RoomTypes (RoomType),
FOREIGN KEY (Zone) REFERENCES Zones (Zone)
);
CREATE TABLE NumberedRooms
(
RoomType VARCHAR(12) NOT NULL,
Zone VARCHAR(10) NOT NULL,
Name VARCHAR(30) NOT NULL,
CHECK (RoomType = 'Numbered'),
UNIQUE (Name),
UNIQUE (RoomType, Zone, Name),
FOREIGN KEY (RoomType, Zone, Name)
REFERENCES Rooms (RoomType, Zone, Name)
);
CREATE TABLE AncillaryRooms
(
RoomType VARCHAR(12) NOT NULL,
Zone VARCHAR(10) NOT NULL,
Name VARCHAR(30) NOT NULL,
CHECK (RoomType = 'Ancillary'),
UNIQUE (Zone, Name),
UNIQUE (RoomType, Zone, Name),
FOREIGN KEY (RoomType, Zone, Name)
REFERENCES Rooms (RoomType, Zone, Name)
);
The CHECK constraints will not be tested by mySQL e.g. do the tests yourself using triggers. Consider adding other tests e.g. that attribute Name in table NumberedRooms represents an integer.
The idea that every row in the supertype table Rooms will have exactly one row in the union of AncillaryRooms and NumberedRooms. This is merely implied e.g. have 'helper' procs to add rows to both super- and subtype tables as a single operation and use triggers to ensure it is done.
Note NumberedRooms has a simple key Name alone, whereas AncillaryRooms has a compound key on (Zone, Name). All three (non-lookup) tables have a key on (RoomType, Zone, Name) throughout, allowing further subtype tables to referencing them and maintain integrity by further testing for valid RoomType values.
You need to increase the amount of RAM, by a LOT. Based on the load you are expecting I'd want at least 64 Gigs in there, if not 128 or 256. Given that most of the database will become pretty stale pretty quick I'd say that one database should be just fine. I've got tables with billions of rows which are OLTP. Granted they are MSSQL, not MySQL but the ideas are the same.
Best Answer
1.
payment(black box)1.1) No currency information?
In the
Paymentstable, although you store anamountanddate, you store no currency. Perhaps you plan on only charging in one currency, but I feel that method will only last so long if this is intended to scale.1.2) What is this second
paymentstable?What is the second
paymentstable for? The one below and slightly left of the actualpaymentstable? It seems to have only anidcolumn, which is the only column in this diagram to specify a data type!? I'm guessing this is some diagram artefact.1.3) You'll need more than just the
nameto take payments!The
payment_methodstable currently doesn't store the type (i.e. credit card, paypal, BitCoin, whatever) of the method. There also seems to be no linked table of payment_types for this either.You will need to store stuff like credit card numbers, etc somewhere (hopefully not in this database!). You will need some sort of linking information for those stored payment methods to be kept in the
payment_methodstable.2.
social(blue box)2.1) Who exactly is
me?I'm assuming the
Metable is some sort of façade or profile type of table. Perhaps allowing a givenUserto shield themselves from the embarrassment of letting their collage/university friends see theMusicthey were into in high school? :PI do not believe it makes sense to double store the first, middle and last names of the user. It would be much better to go with a solution like that which @beeks suggested in the comments above.
2.2)
My_Profile_Details... field?I cannot figure out why this is a single field. I assume it's some sort of
memotype, for storing a lot of text (i.e. a CV of sorts). I think this needs MUCH more decomposition. At a minimum, into Sections of some sort.There also seems to be nothing in a
Profliethat allows a user to select what Schools/Collages/Universities/Enterprises they studied/worked at, etc?3.
classmates(red box)3.1) Internationalisation?
This part of your design is missing information regarding country. Even if you're only looking for schools/colleges in a particular county, employers (which is what I assume
Enterpriseis for) may be in any country.Also, If a classmate starts their own enterprise, do they have the same relationship to that enterprise as someone who works for it?
3.2) Institution Names
You have assumed Universities (and I suppose high schools, primary schools and collages too) have only one name, and that name is in English (or whatever language you're intending to store). It is quite common for universities to have different names in different languages. Institution names can also change over time (renamed, etc).
3.3) Institution Decomposition
Not all Universities divide themselves into Faculties, some are simply a collection of
Schools(think Oxford, etc). These can also change name over time. Also, both faculties (schools), universities (and probably collages, primary and secondary schools too) can merge (i.e. get taken over/bought out) over time.3.4) Institution Location Multiplicity
Your design seems to assume a University can only be in one
town. Many Universities have different campuses in different towns. Some even have campuses across international borders.