The following is a list of some details that are easy to miss when
dealing with class accounts.  This list is meant to augment, not
replace, the detailed account information, so make sure you read the
latter.  You can find the information in the "Miscellaneous links"
section on the class Web site.  

There are four class accounts in all: Two Unix shell accounts and two
database accounts: DC, linuxlab, Oracle, and psql. (See below for
synonyms.)  DC and linuxlab are the Unix accounts.  Oracle accounts
are accessed from DC shell accounts, while psql accounts are accessed
from linuxlab shell accounts.

Some synonyms we may use:
OIT Unix account = Detective Cluster account = "DC" account.
CSIC account = linuxlab account.
PostgreSQL account = psql account.

There is a cluster of "DC" machines, but "dc.umd.edu" will
automatically point you to one of them.  If you grow fond of a
particular one for some reason, you can always use its name to log in
directly as well.

OIT Unix login names are of the form sc424xyz where xyz is a 3-digit
number.  Note that the sc prefix is lowercase here.  Example:
sc424021.  

On the other hand, Oracle login names are of the form
SC424xy where xy is a 2-digit number.  Note that the SC prefix is
uppercase here.  Example: SC42421.  

For linuxlab, you guessed it, the login names have yet another form:
cs424pqr, where pqr is a 3-digit number!  Note that the prefix is a
lowercase "cs" and not "sc"!

Silver lining: The account names (and initial passwords) for psql
accounts match those for the corresponding linuxlab account.

Passwords: Watch out for lower-case vs. upper-case, letter O
vs. number 0, and so on.

You should use ssh (and not telnet) to log into the detective cluster.
Telnet is very insecure.

When you login to DC using ssh, you will need to run the command
"dce_login" after logging in.  When prompted for "principal" respond
with your DC login name, and type in your DC password at the password
prompt.

Oracle accounts: Log in to the detective cluster first.  Then follow
the instructions for Oracle logins.

Do not forget to run "source /usr/local/bin/coraenv".
When prompted for ORACLE_SID, respond with "SC424"; the default
presented to you is almost certainly NOT the correct one!
Accept the default for ORACLE_HOME.

When you run sqlplus, remember to enter your Oracle user-name and not
your DC or some other username at the prompt.  (See above!)
Ditto for password.

The cluster of linuxlab machines is accessible as
"linuxlab.csic.umd.edu"; thus, use something like "ssh -l
yourlinuxlabacct linuxlab.csic.umd.edu" to log in.

For linuxlab accounts, use kpasswd, not passwd, to change your passwords.

To get into psql, use "psql -h sql.csic.umd.edu"; if you type only
psql, you will likely get some strange error.

Use "\h alter user" inside psql to get help on changing your psql
password.  The command \h by itself will give you more general help.

Don't forget to log out completely (from both database and shell
accounts) when you are done.