Processes and Sessions

[joao_rj]

Environment information:
* Oracle version: 10g
* Operating system: Linux

Gentlemen, I have the following doubt ... in relation to the maximum number of Process that we define in Spfile, on the Oracle website the same informs that the session number you need to use Processess as the basis for setting the number and follow the following calculation:


So we have the maximum of sessions bigger than processes, but if for every login in Oracle I create a right session!? And for each session I create a process? If so, the number would have to be the same or not?

The processes refer to the process number that can connect to Oracle simultaneously ... so I did not understand anyone know how to explain?

Thanks!

[diegopedrao]

John,

Let's see if I can explain.

Oracle processes may be of shared type (a server process can serve several user processes) and dedicated (where each process meets a user). However a process can meet several sessions of the same user.

ATT,

Diego Monteiro

[joao_rj]

Hm I think I understood ...

In my case the server is dedicated, then a process per session?

vlw!

[pauloaleo]

Well, let's go. Before arriving in bank processes, let's go for your first doubt.

Each Oracle section opens a process in OS (when dedicated) or shared process (shared) opens a process in the machine OS.

This process is from the operating system, most often see the same as local = No, and if we are in the OS and kill this process, section falls. In Windows do not know how this is seen. Each process open in the SO consumes memory and hardware processing features.

Other is Oracle Processes. These are leased thread to run bank processes that sections request, such as a SELECT ......... this processes allocates bank resources, works in parallel (depending on the hardware configuration) and meets Several sessions sequentially, that is, the session opens, the SELECT runs and the session is inactive with the SQL result. A process was allocated in the bench to run SQL and desaloted, going to another session that requests another execution.

So just processes is one for one. Bank Processes No.

Hugs

[joao_rj]

Many thanks for the reply!

So I can conclude that the parameter in Spfile of Processes does not limit the processes of the Operating System that Oracle opens and rather Oracle's internal processes!

[pauloaleo]

Yes.

In Linux The kernel parameter limiting process is Max User Processes that you see by Ulimit -A.

Hugs