Re: Q:Table Fragmentation. How do I reduce it?

You don't say what you mean by 'a lot' of extents, nor indicate what you consider to be 'small'.

If 'a lot' means a couple of dozen or so, don't worry; if 'small' is still
NOT less than '2 x db_file_multiblock_readcount ' again don't worry.

There is a lot of rubbish stilled quoted about collapsing each object into a single extent, but since that went out with Oracle Version 5, you can ignore it.

A nice position to be in is where all the extents in a given tablespace
are the same size, don't suffer from too many 'incomplete scans' when tablescanning, and don't cause too many entries to appear in fet$ when you drop an object (10 - 40 extents per segment is my target, but
for very small objects I'll put up with 1 extent).

Jonathan Lewis

Rao Uppuluri <uppuluri_at_IDT.NET> wrote in article <6dn7nh$3tr_at_nnrp1.farm.idt.net>...
> Hi all
>
> Setup: Oracle 7.3.2.3 on HP-UX 10.20
>
> I have a table(s) with lot of extents allocated to it. These
 extents are
> small extents. The extents allocated are not all next to each
 other.
> Some are but not all. If I drop the table and recreate it, do I get
 a
> lot of "free space fragmentation"? How do I reduce the
 fragmentation of
> the table? Do I have to export and import the whole tablespace?? (
 I have
> many of these tables with lot of extents allocated to them in the
 tablespace)
>
> Thanx in ADvance
>
> Rao Uppuluri
> (uppuluri_at_XidtX.net -- Please remove X's)
>
>
>
Received on Fri Mar 06 1998 - 00:00:00 CST