A distinction between some computer concepts

The difference between structured and unstructured data

A) structured data: The structure of the data in the database is in the form of a two-dimensional table, and the data of the two-dimensional table in the database management system in the form of entity bytecode files exist in the disk. When a data record is put into storage, all the field properties of the structured data object must be in storage, regardless of whether the field property has a value. field property values that are not assigned can exist in the form of NULL . The advantage of this is that it facilitates retrieval, but increases the memory that stores the data.

b) Unstructured data: Non-structured data is non-relational, that is, not-only SQL. like Lucene ,  MongoDB, Hadoop , among other things, is a model of a non-relational database. They are characterized by simple data processing of the sea volume, which can improve the throughput efficiency of the data and is very flexible.

c) "SQL is not adapted to all of the program code, and for those heavy repetitive operations data,SQL is worth the money." But when the data results are very simple,SQL may not be much use. "

The distinction between design pattern MVC(model-view-control) and software architecture three-tier architecture in software programming:

* *. three-tier architecture: It is a hierarchical development of software projects in the macro sense, involving three layers.

>1. UI (User Interface): The display layer of user data.

>2. BI (bussiness Interface): business logic Interface, primarily responsible for the business of the project

Logical part. This is the core of data processing,

It is the encapsulation processing of the data.

>3. DAI (Date access Interface): Data access interface, user data through the business

After the logical layer is processed, the layer is responsible for the

The interface of the library is processed to perform the data

Insert, delete, modify, query operation.

* *. MVC: Chinese interpreted as model - view - controller. We can understand that the MVC design pattern is a three-tier architecture

Subdivision. It can be understood in the sense of the micro, the first MVC design pattern is from the interface programming

Born in the. Later, the rise ofJava Web Development, the design pattern was applied to Web development. Its

In real mobile network development, This design pattern is a subdivision of the display layer of the three-tier architecture . View Layer

is a dynamic Web page showing a client, the controller is a Servlet, the model layer is the Service layer,DAO

Layer, and the ordinary JavaBean.

All the relevant experimental disciplines are based on physics, because there is a physics subject to the later chemical and biological disciplines.

A distinction between some computer concepts