Re: Creating Logicals before or after populating a file ?

[Evan Harris <spanner@xxxxxxxxxx>]

>
>  If you choose option 1, you fill the PF with records first.  Then as
>each of the LF's is built the system can extract all the keys from the
>PF for that access path, sort them (sorting is nearly Always faster than
>insert after insert), and build a nicely balanced access path.  It can
>use all available memory for this task with little competition. If you
>have DB/2 SMP installed on a multiple processor system it will even use
>all processors to do it even faster.
>

This is pretty much as I had figured, I was interested in the why's and
wherefores, and this is certainly a great explanation.

But what do you mean by "vining" ? Excuse my ignorance, the term rings a
bell, but... ?

Unfortunately it is not a multi processor system, so....

With reference to the other posts, I had a preference toward option 1, but
wanted to be able to provide more explanation to the development team that
developed the application.

Somehow or other in my 15 years on 38's and As/400's: F60.. sheesh... E60..
D60... B60.. Sys/38 mod 700 .. 600.. 400 .... what about a Sys/38 7C1 with
4? 8? meg of memory ;) some of the lessons regarding logicals have become
habit rather than being able to recall the reasons behind it.

If I could only convince these guys that 20 logicals may be excessive..
they have large numbers of logicals built over everything !

Anyway, thanks again for all the posts.. a mine of information as usual.

Cheers
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