Jeffrey,

For dynamic files with records where the record size is large relative to
the key size, I would go with KEYONLY rather than KEYDATA.  We have had
clients whose files (as KEYDATA) have split repeatedly with large records,
so that a file that was 7 gig on Monday would be 19 gig by Thursday, which
made their backups take a huge amount of time.  Setting the split type as
KEYONLY, the same files increased in size, but nowhere near a gig, let alone
12 gig.

Susan Lynch
----- Original Message ----- 
From: "Jeffrey Butera" <[EMAIL PROTECTED]>
To: <[email protected]>
Sent: Wednesday, August 24, 2005 10:18 AM
Subject: [U2] Dynamic files in Unidata


> I have a few questions for those more comfortable with dynamic files in
> unidata.  Currently I have a statically hashed file:
>
> File name                             = H08.CR.FF.TEXT
> Number of groups in file (modulo)     = 13331
> Static hashing, hash type             = 0
> Block size                            = 16384
> Number of records                     = 88030
> Total number of bytes                 = 119079718
>
> It's got a 16K blocksize because the size of the records is all over the
place
> (from a few words to many pages of free form text).  We're dumping in
about
> 50000 new records per year so the file size isn't bad now but in the next
few
> years I anticipate growth (1Gig+) that will most likely lead me to a
dynamic
> file for this application.
>
> My questions:
>
> 1) Can anyone shed insight on 'reasonable' split/merge loads?  By
reasonable,
> I guess I mean I'd like something a little more aggresive than the
defaults:
>
> SPLIT_LOAD=60
> MERGE_LOAD=40
> KEYDATA_SPLIT_LOAD=95
> KEYDATA_MERGE_LOAD=40
>
> I've had someone in the past suggest a split/merge load of 20/10, but have
no
> basis for that suggestion.
>
> 2) Thoughts about KEYDATA/KEYONLY?  I've read the documentation, but I'm
> looking for real-world insight from those who have used dynamic files in
> unidata.
>
> 3) Anything else I'm not thinking about but should?  (Arguments to not use
a
> dynamic file are welcome.)  Currently, my biggest headache is that
resizing
> is taking about 45 seconds - I can only imagine how long it would take if
I
> had 1,000,000 records in there.
>
> -- 
> Jeff Butera, Ph.D.
> Administrative Systems
> Hampshire College
> [EMAIL PROTECTED]
> 413-559-5556
>
> "...our behavior matters more than the beliefs that we profess."
>                                 Elizabeth Deutsch Earle
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