The relationship between the number of Oracle processes and the number of sessions

Want to know the relationship between the number of oracle sessions and the number of processes, and why oracle chooses this relationship?What's the mos documentation for?

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Accepted answer 1:

https://blog.51cto.com/lhrbest/3156119

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Other Answer 1:

https://blog.51cto.com/lhrbest/3156119

Hope this helps you.
If you are satisfied with the answer, please click the accept button!

Other Answer 2:

There is no specific relationship between processes, sessions, and connections. It can be one-to-one or one-to-many. You can refer to askTom:

A connection is a physical circuit between you and the database. A connection might be one of many types – most popular begin DEDICATED server and SHARED server. Zero, one or more sessions may be established over a given connection to the database asshow above with sqlplus. A process will be used by a session to execute statements. Sometimes there is a one to one relationship between CONNECTION->SESSION->PROCESS (eg: a normal dedicated server connection). There is a one to manyfrom connection to sessions (eg: like autotrace, one connection, two sessions, one process). A process does not have to be dedicated to a specific connection or session however, for example when using shared server (MTS), your SESSION will graba process from a pool of processes in order to execute a statement. When the call is over, that process is released back to the pool of processes.

https://asktom.oracle.com/pls/apex/f?p=100:11:0::::P11_QUESTION_ID:5671284058977

Other Answer 3:

https://www.modb.pro/db/37920

You can refer to this article.

Other Answer 4:

Dear teachers, here I understand that a process can have multiple sessions. What I want to know is the relationship between the number of processes and the number of sessions.I have heard two statements, one is that the number of oracle sessions = the number of processes * 1.1+5, and there is another statement that the number of sessions = the number of processes * 1.5. But neither of these two statements specifies the official documentation or other information.I would like to know the correctness of these two statements, and whether there are relevant official documents or information.

Other Answer 5:

You are talking about this database parameter setting

sessions=1.1 * processes + 5

The difference between session and process in Oracle:

A process can have 0, 1 or more sessions, a session can also exist in several processes, parallel is also a session corresponding to a process, the main session is a coordinator session, each parallel process also corresponds to a databasein a separate session.This can be verified from v$px_session and v$session.

The relationship between connections, session sessions and process pocesses
Each sql login is called a connection, and each connection can generate one or more sessions. If the database runs in a dedicated server mode,
A session corresponds to a server process (process). If the database runs in a shared server mode, a server process can serve multiple sessions.

Other Answer 6:

The number of oracle sessions you mentioned = the number of processes * 1.1+5 is the relationship between session and process.In fact, oracle (on linux) has a process to establish a session remotely.Sometimes we kill the session, but we can't kill it all the time.Will find him at the os level, kill.

Oracle single process on windows.

Generally speaking, the benefits of a session and a process are as mentioned above.The downside is that the more sessions there are, the more processes there are.When the number of processes is large, the process that the entire operating system can give is limited.

Other Answer 7:

Is there any official documentation on the statement that the number of sessions = the number of processes * 1.1+5?Can you provide the document number?The production environment in my hand does not seem to match this statement. For example, in a 19.12 production environment, the number of processes is 5000, but the number of sessions is 7552. It seems that the statement number of sessions = number of processes * 1.5 is more credible. What is the reason for this?What caused it?

Other Answer 8:

Thank you teachers for your answers, I have learned that session=processes*1.5+22 after 11g, but I am more curious, how does this 1.5 times come from, why does oracle default to 1.5 instead of others?Are there other considerations for this setup?

Other Answer 9:

Issue closed: Issue has been resolved