A Brief Introduction to the three processes of the Oracle database

OracleThe database has three processes:User Process,Server ProcessAndBackground Process. What are their functions? Next we will introduce them one by one.

User Process runs on the client and is not on the database server. Of course, if you run the client on the server, it runs on the server. For example, the PL/SQL Developer Process we run in Windows is a User Process.

Server Process is a Process mainly used to connect clients and servers. Of course, Server Process has other functions. When a client connects to the Server, we will see an additional Process in the Server Process, which is the Server Process.

Background Process starts when the database instance starts.

The client and server are not on the same machine. When the client connects to the server, it is connected through TCP/IP. When both the client and server are on the same machine and the machine is Linux, the most likely connection at this time is to use IPC connection, and IPC is Inter Process Communication, of course, it may also be through TCP/IP. We can view the Linux Nic through the/sbin/ifconfig file. We will find that one Nic is eth0, the other is lo, And the lo is a Local Loopback ), the IP address is always 127.0.0.1, which is used for local communication.

Background Process is used to maintain and force the relationship between physical and memory structures.

Main background processes:

DBWn PMON CKPT LGWR SMON

Optional background processes:

ARCn LMDn QMNn CJQn LMON RECO

Dnnn LMS Snnn LCKn Pnnn

It reflects the relationship between the Process and the Oracle database.

Here is the introduction of the Oracle process. I hope this introduction will be helpful to you!