Re: DataArea vs. Tables

[DrFranken <midrange@xxxxxxxxxxxx>]

Use them infrequently but have discovered one technical difference 
between the use of a *DTAARA and a table.

If you write to a *DTAARA the system forces the write to disk. Now if 
you have write cache on your disk controllers the write to that cache is 
considered 'well enough' and processing continues. However if you have 
no cache (as a low end system with mirrored disk might have) then the 
write must be actually to disk. When using for a 'next order' number and 
such things this is no problem, however if you are updating the *DTAARA 
with (say) current record position in a massive table (for crash 
recovery for example) then EVERY record position gets forced to disk and 
that slows the job *DRAMTICALLY. If you are using a table or traditional 
database file then the O/S caches that data preventing every write from 
hitting physical disk.

Potentially a rare case I grant you but finding it out at 2AM (when I 
did) was not pleasant.

- Larry "DrFranken" Bolhuis

On 5/13/2011 11:17 AM, Birgitta Hauser wrote:
> Hi guys,
>
>
>
> we just had a discussion about using data areas.
>
> In my opinion they are not heavily used or needed.
>
> I either create a table/physical file or store the information in global
> variables in a specific service program. The data within these global
> variables is set and retrieved by calling procedures.
>
>
>
> I’m just curious, are you using data areas (heavily) or not?
>
>
>
> Mit freundlichen Grüßen / Best regards
>
>
>
> Birgitta Hauser
>
>
>
> "Shoot for the moon, even if you miss, you'll land among the stars." (Les
> Brown)
>
> "If you think education is expensive, try ignorance." (Derek Bok)
>
> "What is worse than training your staff and losing them? Not training them
> and keeping them!"