Database Management System __ Database

The second stage of self-examination textbooks began a few days, and recently have been looking at the database system principle, what function depends on what the transition between models. Indeed a little pressure, but the difficulty is certain, see everyone is so hard to learn, then step up!

Here is my summary of the first three chapters of the database rationale system:

Overall sentiment, people in order to more convenient, and then find ways to create a variety of convenient rules, the database before a few chapters, is a small history, tell you how it is developed, the advantages and disadvantages of each stage of history, and then let you master his design rules. is actually such a routine.

The first chapter of the X-mind

The first chapter of the sentiment:

Database principle system, first talk about the database, we can figure out, this is a repository of data storage, but how to better manage the storage of data, and planning and design data storage, so the first chapter began the database management of some history, and then every history of the replacement, is to make up for the previous piece of data technology shortcomings, through continuous improvement, arrived today. This is the first chapter of the knowledge Point.

Chapter II of the X-mind

The second chapter of the sentiment: the ER model and the basic concept of the relationship model, and the transformation between the two, the ER model is a view, pretending that the view is very complex, so we feel uncomfortable, and then converted into a relational model, so-called relational model is a two-dimensional table, so that everyone can see also understand. The following sections of the textbook are some of the most important points of knowledge, but these are crucial. Although I said, we would like to have you say so simple, I admit, I hope everyone is fearless.

Chapter III of the X-mind

The third chapter of the feelings: the third chapter is the second chapter of the historical moment of introduction, plainly is that we all think of the relationship model of the two-dimensional table let people see convenient, in order to let you better understand and master, and then the third chapter tells you how to design planning, so the function of dependence, what paradigm and so on out, There is the decomposition of the relationship mode, of course, I look very ignorant, the heart of all kinds of spit groove, I just did not read, but the paradigm is a little clear, the third chapter needs to communicate with you.

We have any ideas and better learning methods can communicate with me, this time is still difficult to learn, we can come to the collision of knowledge, not to say there is knowledge, only descendants.