Computer Science and Technology-literacy

1. Tube and Object

The CPU has two statuses:

Tube state: When the CPU processes the system program, the CPU will be converted to a canonicalized state. The CPU can execute the complete set of command systems in the canonicalized state.

Status: Also known as the user State, it is the CPU status when the user program is executed. In this status, privileged commands are not allowed. You cannot directly access system resources or change the machine status. You can only use this program to access your storage region.

2. Primitive (language category of the operating system)

It refers to a process composed of several commands used to complete certain functions, and this process is not interrupted. It must be executed in the tube mode and resident memory, while some operating systems do not run in the tube mode.

3. Atomic operations

It refers to an operation that will not be interrupted by the thread scheduling mechanism. Once this operation starts, it will continue to run until the end, and will not switch to another thread in the middle.

4. Structured Storage

The structured storage method is to apply the principle of the tree file system to a single file system. The tree file system contains subdirectories and subdirectories. Structured Storage stores the data in a file, which greatly improves the efficiency of disk space usage.

5. Structured Data

First, there is a structure, and then there is data. For example, the data storage method in a relational database does not change the structure of the orders table in the storage pot. The logical structure of the data is determined.

6. semi-structured data

Data is available first, with a structure, and can also be used to process structured data. For example, in a nosql stored procedure, the logical structure of a table can be changed and adapted to the expansion of the data structure.

7. unstructured data

Unstructured databases can also be used to process structured and semi-structured data. The stored field length is variable, and each field record can be composed of repeated or non-repeated fields. Unstructured data includes office documents, text, images, XML, HTML, various reports, images, audio/video, etc.

Computer Science and Technology-literacy