Logical File Compilation

[Ram]

Hi All,

I need to create a Logical File over a Live Physical File. The Live
physical contains about 20 million records and is having about 70
logicals already built on it. The new logical which I need to create
will be used by batch programs. But most of the existing logicals are
used by interactive programs. Now can I Create my new logical in the
day time when the application is under use by the users and what are
the things do I need to consider.


Thanks,
Ram

[Gregor Schumacher]

Hi,
there is no problem to create a new logical file at normal day time. But you
should ask yourself if you can reuse one of the 70 other logical files
because the more logical files you have the more the as400 has to do.

regards
Gregor

Post by Ram
Hi All,
I need to create a Logical File over a Live Physical File. The Live
physical contains about 20 million records and is having about 70
logicals already built on it. The new logical which I need to create
will be used by batch programs. But most of the existing logicals are
used by interactive programs. Now can I Create my new logical in the
day time when the application is under use by the users and what are
the things do I need to consider.
Thanks,
Ram

[Ram]

Hi Gregor,

Yes, I have done those analysis for creting new logical files and
justified and also I may have to delete some of the unused/redundant
logicals. So my question is do we have locks on physical while indexes
are built over it and will that reduce system performance for the
interactive jobs using those physical & other existing logicals.

Thanks,
Ram

[Dieter Bender]

Hi,

there will be no locks

performance degradation during building the access path might happen and
depends on the structure of your LF

don't worry too much about the number of LFs, db2/400 shares access pathes
and not every logical file causes an additional access path.

Dieter Bender

Post by Ram
Hi Gregor,
Yes, I have done those analysis for creting new logical files and
justified and also I may have to delete some of the unused/redundant
logicals. So my question is do we have locks on physical while indexes
are built over it and will that reduce system performance for the
interactive jobs using those physical & other existing logicals.
Thanks,
Ram

[Ram]

Dieter,

The structure of LF is quite simple, it is built over 1 PF and its
access path is with 4 fields and also 1 another field with selection
criteria(static).

Thanks,
Ram