Files - Expert Oracle Database Architecture - page 115

• This is how you will process the data in production; you want development to act and react as

your production system would.

• In many cases, the developers pull their code out of the data dictionary, modify it, and compile

it back into the database. The development database holds the current version of the code. If
the development database suffers a disk failure in the afternoon, what happens to all of the
code you compiled and recompiled all morning? It's lost.

Don't let anyone talk you out of being in ARCHIVELOG mode. You spent a long time developing your application, so
you want people to trust it. Losing their data will not instill confidence in your system.

■ there are some cases in which a large DW could justify being in NOARCHIVELOG mode—if it made judicious use
of READ ONLY tablespaces and was willing to fully rebuild any READ WRITE tablespace that suffered a failure by reloading
the data.

Note

Password Files
The password file is an optional file that permits the remote SYSDBA or administrator access to the database.
When you attempt to start Oracle, there is no database available that can be consulted to verify passwords. When
you start Oracle on the local system (i.e., not over the network, but from the machine the database instance will reside
on), Oracle will use the OS to perform the authentication.
When Oracle was installed, the person performing the installation was asked to specify an OS group for the
administrators. Normally, on UNIX/Linux, this group will be DBA by default, and ORA_DBA on Windows. It can be any
legitimate group name on that platform, however. That group is “special,” in that any user in that group can connect to
Oracle “as SYSDBA ” without specifying a username or password. For example, in my Oracle 12 c Release 1 install,
I specified an ora12cr1 group. Anyone in the ora12cr1 group may connect without a username/password:

[tkyte@dellpe ~]$ groups
tkyte ora12cr1 ora11gr2 ora10gr2
[tkyte@dellpe ~]$ sqlplus / as sysdba

SQL*Plus: Release 12.1.0.1.0 Production on Tue Sep 3 14:15:31 2013

Copyright (c) 1982, 2013, Oracle. All rights reserved.

Connected to:
Oracle Database 12c Enterprise Edition Release 12.1.0.1.0 - 64bit Production
With the Partitioning, OLAP, Advanced Analytics and Real Application Testing options

SYS@ORA12CR1> show user
USER is "SYS"

That worked. I'm connected and I could now start up this database, shut it down, or perform whatever
administration I wanted to. But suppose I wanted to perform these operations from another machine, over the
network. In that case, I would attempt to connect using @tns-connect-string . However, this would fail:

[tkyte@dellpe ~]$ sqlplus /@ora12cr1 as sysdba