Database crashed, controlfiles deleted and missing archive logs

Current situation: tonight a database crashed and the controlfiles have been destroyed/deleted. When I tried to open the database then I got:

$ export ORACLE_SID=KARDB
$ sqlplus "sys/password as sysdba"
SQL*Plus: Release 11.2.0.3.0 Production on Tue Apr 22 18:03:00 2014
Copyright (c) 1982, 2011, Oracle.  All rights reserved.
Connected to an idle instance.
SQL> startup
ORACLE instance started.
Total System Global Area 1068937216 bytes
Fixed Size                  2232840 bytes
Variable Size             524291576 bytes
Database Buffers          536870912 bytes
Redo Buffers                5541888 bytes
ORA-00205: error in identifying control file, check alert log for more info

ORA-28000: the account is locked

When you try to login as a user to your database and you get the following error:

$ sqlplus "user/password@database"
...
ORA-28000: the account is locked

ORA-01536: space quota exceeded for tablespace xyz

Today I had this error:

ORA-01536: space quota exceeded for tablespace

So it seems that my user couldn't write to his default tablespace. So deceided to check my user:

SQL> select tablespace_name, username, bytes, max_bytes from dba_ts_quotas where username like '%KAREL%';
no rows selected

TNS lookup over LDAP

This article describes how to migrate tnsnames.ora into LDAP. My current tnsnames.ora looks like this:

$ cat tnsnames.ora
...
PINK=(DESCRIPTION=(ADDRESS_LIST=(ADDRESS=(PROTOCOL=TCP)(HOST=192.168.56.100)(PORT=1521)))(CONNECT_DATA=(SERVICE_NAME=PINK)(GLOBAL_NAME=PINK)))
FLOYD=(DESCRIPTION=(ADDRESS_LIST=(ADDRESS=(PROTOCOL=TCP)(HOST=192.168.56.100)(PORT=1522)))(CONNECT_DATA=(SERVICE_NAME=FLOYD)(GLOBAL_NAME=FLOYD)))
...

Create SPFILE from PFILE

PFILE: traditional init.ora file, changes via eg. vi
SPFILE: binary file, changes via SQL 'alter system...'

To create a spfile login to your database as sysdba locally:

$ sqlplus "sys/oracle as sysdba"

Run the following SQL statement to create a binary spfile from a text pfile: 

ORA-02082: a loopback database link must have a connection qualifier

I have two Oracle databases, one 9.2.0.8 (SID test9) and another 10.2.0.4 (SID test10). I needed to create a database link from test9 to test10 but I always got the following error:

$ sqlplus "sys/password@test9"
SQL> create database link test connect to sys identified by password using 'test10';
create database link test connect to sys identified by password using 'test10'
                         *
ERROR at line 1:
ORA-02082: a loopback database link must have a connection qualifier

ORA-28002: the password will expire within 7 days

When you try to connect to Oracle and you're getting the following error:

$ sqlplus "sys/password"
...
ERROR:
ORA-28002: the password will expire within 7 days
...