Run steps in a chain at a specific time frame

Question

I've got an ETL process running in a scheduler chain. First steps are extracting data from remote servers. Each remote server has it's own time frame in which I can extract the data. Once the window is closing I need to kill the job immediately.
My question is, Is it possible to define a time frame for single steps in a chain ?
Other options i'm considering (but all are less favorable)
Create a job with max_run_duration for each extraction step and manually time the transformation / load chain steps after. Advantage - simple, Disadvantage - A lot of ideal time.
Same as above but make the transformation / load chain with an event based job to when all extraction jobs are done. Advantage - Less ideal time, Disadvantage - More complex, error prune.
These two options requires a sniper job to catch JOB_OVER_MAX_DUR event and kill the job.These options also require breaking up the chain - something I would like to avoid. Another option that keeps the chain intact is
Defining the step rule with a time based condition (and using low evaluation_interval ~ 60 seconds) But then I cannot set max_run_duration and there for cannot stop the job if it's working when the time frame is closing.
I would appreciate any ideas on solving this problem.

Answer 1

Hello,
You can for instance execute the following when you create your Refresh Group:
BEGIN
DBMS_REFRESH.MAKE(
name => '"{color:red}schema{color}"."{color:red}refresh_group_name{color}"',
list => '',
next_date => TRUNC(SYSDATE) + 1 + 1/24,
interval => 'TRUNC(SYSDATE) + 1 + 1/24',
implicit_destroy => FALSE,
lax => FALSE,
job => 0,
rollback_seg => '{color:red}rollback_segment{color}',
push_deferred_rpc => TRUE,
refresh_after_errors => TRUE,
purge_option => NULL,
parallelism => NULL,
heap_size => NULL);
END;
/Then you add your MV to the Refresh Group as follow:
BEGIN
DBMS_REFRESH.ADD(
name => '"{color:red}schema{color}"."{color:red}refresh_group_name{color}"',
list => '"{color:red}schema{color}"."{color:red}MV_name{color}"',
lax => TRUE);
END;
NB: The syntax and option can change with the Release (this syntax is well tested on 8.1.7).
Hope it can help.
Best regards,
Jean-Valentin
Edited by: Lubiez Jean-Valentin on Dec 16, 2009 9:04 AM