Subject Re: [Firebird-Architect] OT: Clustered indexes
Author Miroslav Penchev
On Thu, 30 Jun 2005 07:24:26 +0300, Claudio Valderrama C. <cvalde@...>
wrote:

>> From: Jim Starkey
>>
>> If the space allocation and record distribution is not perfect, the
>> performance of non-indexed retrievals is degraded by the amount of
>> unused space. The performance effect of non-primary index retrieval is
>> more difficult to analyse because it's always bad, but assuming
>> secondard indexes are orthogonal to the primary, cluster effectively
>> guarantees pessimal performance on secondary indexes.
>
> That may explain why MsSql comes with tuning utilities.
> :-)
>

And also explain why these tools of MSSQL for most of our queries just
raise exceptions (errors) or processing them for days without any result
or in best case they finish with nothing to say :( .

Cheers,
--
Miroslav Penchev