Oracle View and modify the maximum number of connections

First step, on the cmd command line, enter sqlplus or Open command window directly in Plsql

Step two, follow the prompts to enter the user name and password

1. View processes and Sessions parameters

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SQL> show parameter processes　　NAMETYPE        VALUE 　　db_writer_processes                 integer1　　gcs_server_processes                integer0　　job_queue_processes                 integer10 　　log_archive_max_processes           integer2　　processes                           integer50

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SQL> show parameter sessions　　NAMETYPE        VALUE　　license_max_sessions                integer0　　license_sessions_warning            integer0 　　logmnr_max_persistent_sessions      integer1　　sessions                            integer60　　shared_server_sessions              integer

　2. Modifying processes and Sessions values　　

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SQL> altersystem set processes=300 scope=spfile; 　　系统已更改。 　　SQL> alter system set sessions=335 scope=spfile;　　系统已更改。

　3. Modifying the processes and sessions values must restart the Oracle server to take effect

The number of connections to Oracle (sessions) is related to the number of processes in its parameter file (process), and their relationships are as follows:
Sessions= (1.1*process+5)

Pick (ii)

　Query the number of connections to the current process of the database:
Select COUNT (*) from v$process;

　　To view the number of connections for the current session of the database:
Elect Count (*) from v$session;

　　To view the number of concurrent connections for a database:
Select COUNT (*) from v$session where status= ' ACTIVE ';

　　To view the session established by the current database:
Select Sid,serial#,username,program,machine,status from V$session;

　Maximum number of connections allowed for query database:
Select value from v$parameter where name = ' processes ';

Or: Show parameter processes;

To modify the maximum number of connections allowed for a database:
alter system SET processes = + scope = SPFile;

(requires restarting the database to make changes to the number of connections)

Restart database:

shutdown immediate;

startup;

See which users are currently working with the data:

Select osuser,a.username,cpu_time/ executions/1000000| | ' S ', Sql_fulltext,machine

from v$session a,v$sqlarea b

where a.sql_address = b . Address

ORDER by cpu_time/executions Desc;

Note: UNIX 1 users session corresponds to an operating system process, while Windows embodies the thread.

start Oracle

su-oracle

sqlplus system/pwd as SYSDBA//Enter S QL

Startup//Start database

lsnrctl start//Start monitoring

sqlplus "/as sy Sdba "

shutdown immediate;

startup mount;

ALTER DATABASE open;

However: I changed the maximum to 1200,java 356 and then the error

Oracle View and modify the maximum number of connections