Sys User Logon for oracle9i

The sys user of oracle9i recently installed an oracle9i on linux. When using sqlplus to log on, there was a confusion. Now, it is recorded, so it is better to remember it... It has always been believed that an as dba should be added after logon using the sys user, that is, the dba should be used for logon. However, this time we found that oracle on linux can log on to C: \ Documents and Settings \ Administrator> sqlplus sys/sys @ ora9ivm SQL * Plus without adding as dba: release 9.2.0.1.0-Production on Monday May 13 09:15:24 2013 Copyright (c) 1982,200 2, Oracle Corporation. all rights reserved. connect to: Oracle9i Release 9.2.0.4.0-ProductionJServer Release 9.2.0.4.0-Production and as dba. But later found that if not added as sysdba this sentence, the permission will be much less, the most obvious is that there is no permission to close the database SQL> shutdown immediateORA-01031: insufficient privileges: At this time, the sys user is just like a common user and later knows that this is related to an oracle parameter, SQL> show parameter o7 NAME TYPE VALUE ---------------------------------- export O7_DICTIONARY_ACCESSIBILITY boolean TRUE O7_DICTIONARY_ACCESSIBILITY this parameter seems to be compatible with oracle in earlier versions. Modify this parameter: SQL> alter system set O7_DICTIONARY_ACCESSIBILITY = false scope = spfile; the system has changed. Restart the database. SQL> shutdown immediate; the database has been closed. The database has been detached. The ORACLE routine has been disabled. The SQL> startupORACLE routine has been started. Total System Global Area 236000356 bytesFixed Size 451684 bytesVariable Size 201326592 bytesDatabase Buffers 33554432 bytesRedo Buffers 667648 bytes database loaded. The database has been opened. Login again, if you do not add as sysdba can not log on to the SQL> conn sys/sys @ ora9ivmERROR: ORA-28009: connection to sys shoshould be as sysdba or sysoper warning: you no longer connect to ORACLE. Add as sysdba to log on to the normal SQL> conn sys/sys @ ora9ivm as sysdba is connected. Check the parameter SQL> show parameter o7 NAME TYPE VALUE -------------------------------------- invalid O7_DICTIONARY_ACCESSIBILITY boolean has been changed to FALSE. In addition, the default value of this parameter is false for oracle in windows. Therefore, add the as sysdba parameter in windows unless you change O7_DICTIONARY_ACCESSIBILITY to TRUE.