Re: strategy to rebuild/reorganize table with LOBs
- From: Neil Kodner <nkodner@xxxxxxxxx>
- To: Craig Hagan <hagan@xxxxxxx>, oracle-l-freelists <oracle-l@xxxxxxxxxxxxx>
- Date: Fri, 9 Apr 2010 07:20:04 -0400
Never given it a try. I'm also looking for suggestions on tuning
pctfree/pctused and based on the contents of my clobs, whether or not to
store them inline or out of line. any recommendations?
On Fri, Apr 9, 2010 at 7:09 AM, Craig Hagan <hagan@xxxxxxx> wrote:
> Why not dbms_redefine?
>
> On 4/8/10, Neil Kodner <nkodner@xxxxxxxxx> wrote:
> > I have a letters table, it's 5.6M rows, 405 avg row len, 2837038 8k
> blocks.
> > 2 LOBs. the lobs are in-line. For whatever reason, these LOBS are
> mostly
> > NULL. Out of 5.6M rows, one of the lobs has 205,398 values, 7900 of
> which
> > are larger than 4000 characters. The other lob has 4.5M values, only 2
> of
> > which are larger than 4000. This table takes FOREVER to full-scan, be it
> an
> > analyze or an export, select count, or anything else that requires a full
> > scan. Additionally, queries against indexed columns result in long run
> > times with a lot of LIO/PIO.
> >
> > I'm having some row chaining/migration problems with this table and it
> > appears to be a good candidate for a rebuild, with a new values for
> PCTFREE
> > /PCTUSED. The table currently has a PCT_FREE of 40 and PCT_USED is not
> set.
> >
> >
> > I dont know if the fact that the lobs are inline(or the lobs in general)
> are
> > causing issues, or if the values for pctfree/pctused is. I can say that
> > this is the worst performing table in my application. Im thinking of
> > export/truncate/import this weekend but want to make sure its done
> > correctly. I thought a value of 40 would be ok for pctfree. The lobs
> and
> > how they're being used, with all of the NULLS are throwing me for a loop.
> > I'd appreciate some help in configuring this table for export/import.
> >
>
> --
> Sent from my mobile device
>
> .- ... . -.-. .-. . - -- . ... ... .- --. .
>
> Craig I. Hagan
> hagan(at)cih.com
>
> "Tout ce qui est exagéré est insignifiant.": ("All that is
> exaggerated is insignificant.")
>
> Talleyrand
>
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