Re: Fragmentation in Oracle

Hi,

This is not called "fragmentation" in Oracle (no file fragmentation) Each time you add records, your HWM (High Water Mark) can increase, but never decrease until you truncate the table.

The best use of your space is tuned by the storage parameters (PCTUSE PCTFREE). You can see if your add and delete records are somewhat equivalent (in size) or not by searching in DBA_SEGMENTS (group by .. I don't remember just now). If your table grows and you think that it's not logical, try to change storage parameters.

Your export/truncate/import may fill your blocks if you choose good storage parameters (depending your update need) but certainly avoid linked blocks (caused by increasing size of data by updating records)

Hope this helps.

--
REIP Jean-Claude
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Jorge A. San Martín wrote in message <3461EA2B.73C6620B_at_tortuga.its.cl>...


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>

>Jorge A. San Martín wrote:

>

>> Hi,


>> I'm using Oracle 7.3.2.3 on an Alpha with OSF/1 v4.0, and I have some

>> questions.

>> First, fragmentation problem exist?

>> Second, I have a process what makes "depuration", it does not delete all

>> the records from a table, just the ones that  meet a condition, I

>> suppose that this operation makes some fragmentation, how can I fix

>> this? I'm  thinking of making an export of the table, truncate it and

>> import it, but this is very ineficient, we are calculating 1,000,000

>> records a day :(

>> What would you recomend?

>>

>> That is all, thanks,

>>

>>        Jorge San Martin

>

>It's me again, my e-mail is

>    jsanmart_at_dcc.uchile.cl

>

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