Database schema components

1. Oracle is an important place in the company and the breadth of applications.

2. Oracle Overview, which emphasizes the role of the root, which is Oracle's overall architecture, is mastered by 40% of Oracle knowledge.

3. static files in the database do not start is the operating system file, after startup is the database process.

4. dynamic files, mainly the SGA sharing area and some core processes.

5. The User process is primarily a client, and server process is primarily a server process, and the PGA of the server processes is not shared memory.

6. database files (static files), mainly configuration parameters files, ultra-user files, data files, control files, log files and so on.

7. database instances (dynamic files), which are primarily used to access databases, including memory structures and background processes.

8. There are three ways to connect a DB instance, including 1) the direct connection between user and server, 2) the user and server are connected via the network, 3) the browser and user are connected via the network, and user and server are connected via the network. The user is in the middle of the application server layer.

9. The role of the shared pool in the SGA, mainly 1) the library cache (buffer) is mainly used to cache SQL statements, etc. 2) data dictionary cache (data dictionary buffer) is used primarily to buffer tables, etc. Both of these methods are designed to improve the efficiency of database operations.

10. The role of data buffer cache in the SGA is primarily used to cache the most frequently used user blocks.

11. The PGA (program Global Area) of the server process is unshared and can only be written by the server process, which includes the sort area, session information, cursor State, and so on.

Database schema components