DA Morgan ha scritto:
> Andrea wrote:
>> On 5 Set, 13:58, sybrandb <sybra..._at_gmail.com> wrote:
>>> On Sep 5, 1:09 pm, Andrea <netsecur..._at_tiscali.it> wrote:
>>>
>>>
>>>
>>>> Hi,
>>>> i was reading some paper related on clustering factor, this column
>>>> aimed to identified if the rows of a table are synchronized (ordered)
>>>> with the index.
>>>> If i don't mistake, the value of clustering_factor have to approached
>>>> to number of blocks of the table and more far away from number of
>>>> rows.
>>>> So, if i have understood well, main indications on this column are:
>>>> 1) if c factor is lower than blocks, maybe the table could have
>>>> problems of fragmentation because of many DML statements (insert and
>>>> delete)
>>>> 2) if c factor is higher than blocks and it approach to num_rows, then
>>>> the rows in the index are not ordered (not sync with the index).
>>>> In first case: is SHRINK the table a method for resolve the problem?
>>>> In second case: rebuild index resolve order of the rows ?
>>>> Or, for both case the only best method is truncate and reinsert all
>>>> rows?
>>>> thanks for your advice and opinions.
>>>> bye
>>>> --
>>>> Andrea
>>>> ( a guy that tries to become to DBA)
>>> The best method is to bother only when it will *resolve* anything.
>>> Otherwise you are embarking on an exercise in futility and getting
>>> paid for wasting your and your employers time.
>>>
>>> --
>>
>> sorry but i discord with you, some crumbs of my FREE time i dedicated
>> for learn and increase my competence.
>> I think that one (but important) of DBA role is "also" do a proactive
>> tuning of database.
>> what is badly in this?
>> if i search and engage to find possible bottleneck (leaf blocks,
>> chained rows, objects fragmentation, waits, clustering factor, etc..)
>> i could to avoid that this become to a problem (reactive).
>
> To be proactive is a good thing. But there is a line that separates
> being proactive and having, as Gaja Krishna Vaidyanatha has called it,
> "Compulsive Tuning Disorder." More people have the later.
>
> I too am in agreement with Sybrand. It appears that faced with a need
> to do "something" you have chosen an arbitrary "something" without
> metrics supporting that that "something" has any value.
yes, i agree with your.... "mea culpa", i have given my excuses.
I have mistaked, i have thought that this newsgroup is useful also for
exchange our opinions or to discuss also this arguments.
Received on Wed Sep 05 2007 - 14:22:26 CDT
