The difference between ALTER DATABASE and ALTER SYSTEM and ALTER session

Source: Internet
Author: User


1, the system is the instance level, database is the data base level, session is conversation level.

2, about these three levels of changes in the following general

Database-level (relatively large) > instance-level > Session-level (for current conversations only)

3. Related attributes

"Alter session SET *****=****"//valid for current session

"Alter system set *****=****"//Is permanent (System) valid

"ALTER DATABASE Set *****=****"//is usually changed to static parameters


ALTER DATABASE changes the properties of a data base, generally changing the physical, can be seen

For example: Alter dtabase rename DataFile


Alter system dynamically alters the properties of a database routine, which is generally logical, invisible

For example: Alter system set Db_cache_size

Alter session changes the properties of a session

For example: Alter session set Nls_language


This article is from the "Travel Life" blog, please be sure to keep this source http://felixgzf.blog.51cto.com/4108324/1792157

The difference between ALTER DATABASE and ALTER SYSTEM and ALTER session

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