In 10g, when ORA-00020 occurs, Sqlplus will report "connected to an idle instance"
From:
Sqlplus Logon Reports ' connected to a idle instance ' when ORA-20 happens in 10g (document ID 1370000.1)
Say the more classic, do not translate, direct reprint:
Applies To:
Oracle server-enterprise edition-version:10.1.0.4 to 10.2.0.5-release:10.1 to 10.2
Information in this document applies to any platform.
Symptoms
When the maximum number of processes are reached, and a next normal logon reports an ORA-20, a subsequent local connect as SYSDBA reports:
SQL> connect / as sysdba
Connected to an idle instance.
Trying to start up the database reports:
ORA-01081: cannot start already-running ORACLE - shut it down first
The issue can reproduced with the following steps:
1. Using a 10g database, build sufficient processes until an ORA-20 occurs
2. Then execute
SQL> connect / as sysdba
Note:
Connecting from the OS command prompt using
$ sqlplus/as SYSDBA
The SYSDBA would get the "Connected" message
Cause
This are expected behavior in Oracle 10g, and are explained in unpublished
Bug 2935090-sqlplus REPORTS CONNECT to the IDLE INSTANCE when INSTANCE reaches MAX PROCESSES.
The reason we don t display error ORA-20 is because your is login as
SYSDBA. Being DBA User must is able to login regardless of the status of
the database, so then you can take the necessary action to rectify the
problem.
as when login as normal user, you is getting the appropriate error but does
Not tell you the process limit. This is because the message was from RDBMS
layer So we have the no control of that. The cause and Action for
This message, state very clear , what are you need to do.
.
00020, 00000, "Maximum number of processes (%s) exceeded"
//*cause:all Process state Objects is in use.
//*action:increase The value of the PROCESSES initialization parameter.
Solution
Ignore this ' Connected to an idle instance. ' Message and handle it just as a normal ORA-20 error.
The behavior have been changeg in Oracle 11g where it reports a ' ORA-20 ' instead of ' Connected to an idle instance. '
"Translated from MoS article" in 10g, when the occurrence of ORA-00020, Sqlplus Landing will be reported "connected to an idle instance"