Oracle background process Introduction

Oracle background processes are an important part of the Oracle database framework. The following describes various types of Oracle background processes for your reference and use.

Oracle background processes include Database Writer, DBWR, Log Writer, LGWR, System Monitor, and SMON, PMON), Checkpoint Process (CKPT), archiving Process, service Process, user Process)

Data Writing Process: responsible for writing changed data from the database buffer cache to the data file

Log writing process: writes changes in the redo log buffer to online redo log files.

System Monitoring: Checks Database Consistency and starts database recovery when the database is opened if necessary.

Process Monitoring: clears resources when an Oracle process fails.

Checkpoint Process: updates the database status information in control files and data files whenever changes in the buffer cache are permanently recorded in the database. The process changes the title of all data files at the check point to indicate the checkpoint. Generally, this task is executed by LGWR. However, if the checkpoint significantly reduces system performance, the CKPT process can run to separate the work of the checkpoint originally executed by the LGWR process, which is implemented by the CKPT process. For many applications, the CKPT process is unnecessary. CKPT runs only when the database has many data files and the LGWR significantly reduces the performance at the check point. The CKPT process does not write blocks to the disk. This task is completed by DBWR. The CHECKPOINT_PROCESS parameter in the init. ora file controls the Enable or enable CKPT process. The default value is FALSE.

Archiving process: backs up or archives a full log group during each log switch.

Service Process: User process service.

User process: On the client, the user is responsible for passing the user's SQL statement to the service process and retrieving the query data from the server segment.

Online redo Oracle Log File Size

How to delete ORACLE archive logs

Oracle mobile data file Method

Concepts of oracle users

Add Oracle user information in Linux