Its not just the number of secondaries, but the clustering of the hash
result producing long secondary chains that you might need to worry about.
I had a case once where inserting new records get very slow - the keys being
added were sequentially allocated document numbers (eg Invoice nos A12345,
A12346 etc). I had to increase capacity a few times before I found the magic
number that moved the synonyms away from the current area of insertion keys.
jp
----- Original Message -----
From: "Rene Woc" <[log in to unmask]>
To: <[log in to unmask]>
Sent: Tuesday, April 06, 2004 8:45 AM
Subject: Re: [HP3000-L] Secondaries


> At 3:25 PM -0400 4/5/04, Joshua wrote:
>
> >Is there an Utility on the HP3000 that will tell how If you have
> >secondaries or how many you have?
>
> In addition to the excellent replies that you have received to
> your question, you are probably interested in knowing how
> secondaries affect your database's performance.
>
> We have several technical articles on this topic available at
> Adager's web site ( http://www.adager.com ). Some examples:
>
>    The Path to Improved IMAGE Detail Dataset Performance
>    by Patrick Mullen
>
>    IMAGE Performance by Ken Paul
>
>    Do migrating secondaries give you migraines?
>    by Alfredo Rego
>
>    The Three Bears of IMAGE, The Use and Abuse of Non-hashing Keys
>    in IMAGE and Integer Keys: The Final Chapter by Fred White
>
>
> Cordially,
>
>
> Rene
>
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