Managing oracle processes

<1>.Server Processes

(1)Dedicated server process

In the following situations,you must connect to an instance using a dedicated server prosess:

To submit a batch job

To use Recovery Manager to back up,restore,or recover a database

(2)Shared server process

In a shared server configuration, client user processes connect to a dispatcher. A dispatcher can support multiple client connections concurrently. Each client connection is bound to a virtual circuit. A virtual circuit is a piece of shared memory used by the dispatcher for client database connection requests and replies. The dispatcher places a virtual circuit on a common queue when a request arrives.

Configuring Oracle for the Shared Sserver:

Initialization Parameter for Shared Server

1.DISPATCHERS (is required by shared server)

You can set in an ALTER SYSTEM statement;

Typically one dispatcher for every 1000 connectsions;

Example:

Forcing the ip address used for dispatchers

DISPATCHERS=”(ADDERSS=(PROTOCAL=TCP)

(HOST=10.133.133.133))(DISPATCHERS=2)”

Forcing the port used by dispatchers

DISPATCHERS=”(ADDRESS=(PROTOCOL=TCP) (PROT=1527)”

V$QUEUE,V$DISPATCHER,V$DISPATCH_RATE;

Shutting down specific dispatcher processes

ALTER SYSTEM SHUTDOWN IMMEDIATE ‘D001’;

2.MAX_DISPATCHERS (is optional ,if not set ,oracle selects defaults)

3.SHARED_SERVERS

A dynamic initiazalization parameter;

Oracle dynamically adjusts the number of shered server processes based on the length of the request queue;

Typically one shered server for every ten connections;

4.MAX_SHARED_SERVERS

A static initialization parameter

5.CIRCUITS (specifies the total number of virtual circuits that are available for inbound and outbound network sessions)

6.SHARED_SERVER_SESSIONS

7.LARGE_POOL_SIZE

8.SESSIONS

Oracle background processes