Wednesday, May 14, 2014

_single_process Initialization Parameter

The _single_process initialization parameter allows you to start an instance in single process mode. As it begins with an underscore, you should only use it when Oracle tell you to. When I tried it on Oracle 10 and Oracle 11 test databases, they promptly fell over. However, I was able to get it to work on Oracle 9, although it produced an ORA-00600. I then left the SYSDBA session open: 

Oracle 9: sqlplus '/ as sysdba'
 
SQL*Plus: Release 9.2.0.7.0 - Production on Mon Nov 11 18:49:19 2013
 
Copyright (c) 1982, 2002, Oracle Corporation.  All rights reserved.
 
Connected to an idle instance.
 
SQL> startup
ORACLE instance started.
 
Total System Global Area  106139816 bytes
Fixed Size                   733352 bytes
Variable Size              75497472 bytes
Database Buffers           29360128 bytes
Redo Buffers                 548864 bytes
ORA-00600: internal error code, arguments: [ksfdgfnm1], [0x40228B858], [], [],
[], [], [], []
 
SQL> col value format a30
SQL> select value from v$parameter
  2  where name = '_single_process'
  3  /
 
VALUE
------------------------------
TRUE
 
SQL> 

… and a subsequent login attempt from another server session failed with an ORA-00024: 

Oracle 9: sqlplus /
 
SQL*Plus: Release 9.2.0.7.0 - Production on Mon Nov 11 18:36:55 2013
 
Copyright (c) 1982, 2002, Oracle Corporation.  All rights reserved.
 
ERROR:
ORA-00024: logins from more than one process not allowed in single-process mode
 
Enter user-name:

No comments: