Tuesday, November 13, 2012

[OS] Basic Cron Management

Cron is a job scheduler for *nix operating systems. It is time-based, i.e. can periodically run scripts at certain times. Its main purpose is to automate system maintenance.

The crontab file is the configuration file that specifies the commands that will be executed on a specific moment. Users can have their own crontab file or can use the system crontab file.

The base format of the crontab entry is the following:
minute hour day month day-of-week command-to-execute

[RDBMS] What is ORACLE_UNQNAME?

The ORACLE_UNQNAME is an environment variable that is set to the database’s unique name.

To find its value you must run the following query in the database instance using SQL*Plus (as SYSTEM user):
SELECT name, db_unique_name FROM v$database
 Problem solved!

[RDBMS] Enable Database 11g Console

To enable the Database Control in an Oracle Database 11g you should complete the following tasks:

1. Login as oracle in the server.
2. [Optional] Delete any previous installation. It will ask for Database SID, Listener Port Number, Oracle Home Location and SYS/SYSMAN/DBSNMP Password:

emca -deconfig dbcontrol db -repos drop