HOW TO RUN A SQL PLUS SCRIPT FROM A CRON JOB

PURPOSE:
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HOW TO RUN A SQL PLUS SCRIPT FROM A CRON JOB.

SCOPE & APPLICATION:
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This article is intended for an audience having knowledge about unix and sql.

EXPLANATION:
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Cron is a mechanism for planning and scheduling batch jobs. The daemon "crond" is started automatically on system boot up. It runs one check per minute to see if there are any jobs to execute. The list of jobs to execute is created by the program "crontab".

Entering the command "crontab -l" will display a list of current entries. By default, only entries owned by the logged in user will be displayed.
Existing lists can be removed/deleted with command "crontab -r".

To create a new list, it is recommended to read the entries from a file using the command

"crontab filename".

To run a sql script, create a file (for ex: script1.ksh) containing the sql commands. Now use the following crontab entry.

#The following entry will execute the script 1.ksh every hour.
0 12 * * * $ORACLE_BASE/admin/scripts/snap.ksh

This entry consists of six parameters. The first five parameters define the time schedule, whereas the sixth parameter contains the command for executing the job.
This command consists of:

- the full path and file name of the script - an argument

Parameters defining the time schedule are:

minute(0-59)
hour(0-23)
day of month(1- 31)
month(1-12)
day of week(0-6) 0 = Sun

Hence, the above sample entry: 0 12 * * * can be translated as:

If Minute = 0 and Hour = 12, the script will be executed.

Because the last three scheduling parms are defined by the wildcard character
"*", the job will be executed every day.

REFERENCES:
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For further explanations under Unix enter the following commands:

man crontab
man 5 crontab
man cron