Re: Re: what's mean of "enqueue hash chains" latch?
- From: eygle <oracle.unix@xxxxxxxxx>
- To: biti_rainy <biti_rainy@xxxxxxxxx>
- Date: Sun, 9 Jan 2005 13:29:33 +0800
hello,biti;
I've said :we have no "Buffer wait Statistics" output from statspack.
So,No v$waitstat output there.
thanks.
On Sun, 9 Jan 2005 12:56:00 +0800, biti_rainy <biti_rainy@xxxxxxxxx> wrote:
> hi,eygle
>
> show us the v$waitstat ?
>
> anyway , increase the number of freelists and freelist group may or
> may not be helpful. if you can ,just have a try.
>
> btw:
> with multiple freelist groups,need recog the segment, the freelists
> header of a group can use a separate block,not the segment header ,2
> groups use 2 separate blocks. NONE OPS can use multiple freelist groups
> too,it would reduce the contention of the segment header.
>
>
> Best regards
>
> msn: biti_rainy@xxxxxxxxxxx
> a dba from alibaba(china)
>
> ---- from the mail-----
> >Thanks Pete;
> >
> >In fact ,at that moment ,only the operation is excute in databasee.
> >So ,no often commit ,from statspack report:
> >
> >I am agree that we may need to increase freelists for parallel
> >operation,but at that monment,we have no "Buffer wait Statistics"
> >output from statspack.
> >
> >thanks for you info,it's useful to me.
> >
> >On Sat, 8 Jan 2005 17:01:13 -0000, Peter.Hitchman@xxxxxxxxxxx
> ><Peter.Hitchman@xxxxxxxxxxx> wrote:
> >> Hi,
> >> From MetaLink:-
> >>
> >> "dml lock allocation
> >> This latch protects the list of State Objects (dml locks). Every time a
> >> transaction modifies a table, a DML lock is gotten and released when the
> >> change is committed. The number of State Objects for dml locks is
> >> determined by
> >> the init.ora <Parameter:DML_LOCKS>".
> >>
> >> So I would be looking at how often you commit.
> >> Also what sort of turn over are you getting on the online redo logs? It
> >> may well be that they are too small.
> >> You may want to investigate having multiple freelists for the table you
> >> are inserting into, having many parallel
> >> inserts (assuming you have enabled parallel DML), may well be causing a
> >> lot of contention for the header block at
> >> the start of the segment.
> >>
> >> Good luck.
> >>
> >> Pete
> >
> >----------------------------------------
> >eygle from China.
> >my site: http://www.eygle.com
> >--
> >//www.freelists.org/webpage/oracle-l
> >
> >.
>
>
--
----------------------------------------
eygle,a beginer of Oracle from China.
my site: http://www.eygle.com
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