The use of sessions_per_user when creating a profile:

For example:

Create a profile for xiaoming while allowing two users to connect

SYS@ odb > create profile prof_xiaoming limit sessions_per_user 2

Profile created.

/ / the user is bound to profile

SYS@ odb > alter user xiaoming profile prof_xiaoming

User altered.

/ / Grant permission to create a session

SYS@ odb > grant create session to xiaoming

Then use this user to log in to several clients without reporting an error; question: here limit the number of login session to 2 why it is possible for the terminal to log in 3 or 4, and no error report is prompted.

It turns out that resource restrictions are not enabled.

SYS@ odb > alter system set resource_limit=true

System altered.

When you log in as xiaoming user again, you will be prompted to exceed the limit and cannot log in.

SYS@ odb > conn xiaoming/xiaoming

ERROR:

ORA-02391: exceeded simultaneous SESSIONS_PER_USER limit

Warning: You are no longer connected to ORACLE.

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