Concepts of oracle users

Oracle users are generally "people" who access oracle databases ". Next let's take a look at some oracle user knowledge.

1. User concepts
Oracle users, that is, users, are generally "people" who access oracle databases ". In oracle, various security parameters of oracle users can be controlled to maintain database security. These concepts include schema), permissions, roles, storage settings, space limits, access resource restrictions, database audit, and so on. Each user has a password, and the correct user/password can be used to log on to the database for data access.

Ii. User's default tablespace
The tablespace is the maximum logical unit for information storage. When an oracle user connects to the database for data storage, if the target tablespace is not specified, the data is stored in the user's default tablespace. For example, create table mytable (id varchar2 (20), name varchar2 (100); this statement creates a table mytable and stores it in the default tablespace of the current user, to specify a tablespace, create table mytable (id varchar2 (20), name varchar2 (100) tablespace tbs1 ;. You can specify the default tablespace when creating a user, or use the aler user command to specify the tablespace. For more information about the syntax, see the following section.

Iii. User temporary tablespace
Temporary tablespace is mainly used for sorting order by statements and other intermediate operations. Before oracle9i, you can specify that users use different temporary tablespaces. From 9i, temporary tablespaces are generic and all users use TEMP as temporary tablespaces.

Iv. user resource files
Oracle user resource files are used to restrict user resource access, including: cpu usage time limit, memory logical read limit, session data limit that each user can connect to at the same time, the space and time limit of one session, the duration limit of one session, dedicated for each session SGA space limit.

V. User tablespace quota
The tablespace storage limit is the total number of buckets that a user can use in a tablespace. You can specify the quota parameter when creating or modifying a user. If you exceed this limit when storing data in a tablespace, an error occurs. Error message: 'ora-01536: space quota exceeded for tablespace tablespacename ..'. You can query the dba_ts_quotas dictionary to view the tablespace quota information.

6. Create an oracle user resource file
The syntax for creating a user resource file is as follows:
Create profile filename LIMIT
SESSION_PER_USER integer
CPU_PER_SESSION integer
USER_PER_CALL integer
CONNECT_TIME integer

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