Re: oracle job

Anurag Varma <avdbi_at_hotmail.com> schreef in berichtnieuws BMjYa.27986$tt1.13970_at_news02.roc.ny...
|
| "Anton Buijs" <remove_aammbuijs_at_xs4all.nl> wrote in message
news:3f31425f$0$49100$e4fe514c_at_news.xs4all.nl...
| >
| > Solaris77 <giofai_at_inwind.it> schreef in berichtnieuws
| > bgr054$r953n$1_at_ID-203060.news.uni-berlin.de...
| > | Hi,
| > | i have 1 oracle job starting every 2 hours.
| > | My question is:
| > |
| > | if the oracle job starts 12:00 and it's running at 14:00 what's
happening?
| > |
| > | The new job start or wait the finish of the first job??
| > |
| > | PS Sorry for my english!!
| > |
| > | Thank
| > | Giovanni
| > |
| >
| > Oracle calculates the next job execution time when the job finishes. It
uses
| > the function you specified as the "interval" parameter. Example:
| > - suppose interval is "sysdate +2/24" (means: every 2 hours)
| > - job started to run at 12:00 (while running you can see that in
dba_jobs
| > columns this_date and this_sec or the view dba_jobs_running)
| > - job finishes at 15:05 (see view dba_jobs columns last_date and
last_sec)
| > - Oracle calculates a new scheduled time (dba_jobs columns next_date and
| > next_sec) using interval, resulting in 17:05 in this example.
| >
| >
| >
|
| Anton,
|
| I do not think that you are correct.
|
| A job which runs for 3 hours, if scheduled to run every 2 hours .... will
run every (approx.) 3 hours.
|
| So
| - job starts at 12:00 and finishes at 15:05
| - the next job will start pretty soon after 15:05
|
| .. thus if a job takes longer than its interval ... it will behave as a
continuous job.
|
| And since job puts a "job lock", only one of them will be running at one
time.
|
| Try out a simple example using dbms_lock.sleep. Pretty easy to test this.
|
| .. so the answer to OP's question is: Only one job will be running at one
time. However, in his case .. as soon
| as the job finishes, another will start. So "new job will wait for the one
currently running to finish".
|
|
| Anurag
|

I tested it and I must admit: you are totally right. I was so convinced about what I described as the behaviour, don't know how that has settled in my mind. But now that is updated and commited. It is in the doc too. From the Oracle Administrators Guide, Chapter Managing Job Queue:

Job Execution Interval:
The INTERVAL date function is evaluated immediately before a job is executed. If
the job completes successfully, the date calculated from INTERVAL becomes the
new NEXT_DATE. If the INTERVAL date function evaluates to NULL and the job completes successfully, the job is deleted from the queue. Received on Thu Aug 07 2003 - 13:26:59 CDT