RE: Question about sequential scans
About 8 million, so it would be nice to ensure we're not really seeing
30000 sequential scans on a busy day. This is used by an OLTP app...
DC
> -----Original Message-----
> From: informix-list-bounces@iiug.org [mailto:informix-list-
> bounces@iiug.org] On Behalf Of bozon
> Sent: Wednesday, August 02, 2006 11:15 AM
> To: informix-list@iiug.org
> Subject: Re: Question about sequential scans
>
> How many records are in each partnum?
>
> Doug Conrey wrote:
> > It's all just one run of onstat. Having filtered out records for
other
> > tables, today's output (so far) looks like this:
> >
> > Partition profiles
> > partnum lkrqs lkwts dlks touts isrd iswrt isrwt isdel bfrd
bfwrt
> > seqsc rhitratio
> > 0x800161 692430 0 0 0 16947113 2041 9724 429
43323655
> > 16881 4703 100
> > 0xc00017 684558 0 0 0 16897256 2059 9910 445
28204359
> > 17075 2 100
> >
> > The wrapping may make this look a little awkward, but the point is
that
> > the seqsc value is 4703 in one partition and 2 in the other. The
schema
> > (minus fields) looks like this:
> >
> > CREATE TABLE "dba".inv_billacts (
> > ...
> > ) WITH ROWIDS
> > FRAGMENT BY ROUND ROBIN IN
> > data01,
> > data02
> > EXTENT SIZE 5500928 NEXT SIZE 550912 LOCK MODE ROW;
> >
> > I did note that not all the indices on this table are explicitly
> > detached (some are). I thought, though, that in 9.4+ all indices
would
> > be in their own tblspace by default. I would think that attached
indices
> > might produce this, however, if full index scans were being counted?
> > Could the rowids be doing it?
> >
> > DC
> >
> > > -----Original Message-----
> > > From: informix-list-bounces@iiug.org [mailto:informix-list-
> > > bounces@iiug.org] On Behalf Of bozon
> > > Sent: Wednesday, August 02, 2006 6:39 AM
> > > To: informix-list@iiug.org
> > > Subject: Re: Question about sequential scans
> > >
> > > Did someone clear stats between runs with onstat -z?
> > >
> > > Can you send more detail?
> > >
> > > Doug Conrey wrote:
> > > > We're running IDS 9.4.FC5 on AIX 5.2. I have a table that is
> > fragmented
> > > > by round robin in two dbspaces. It does have rowids (not my
> > decision),
> > > > and a number of indices. I've been noticing that the onstat -g
ppf
> > > > output for the two partitions have wildly different numbers of
> > > > sequential scans. Today, for instance, one partition has 11,000
or
> > so,
> > > > the other has 2. How does that make any sense? Surely in a round
> > robin
> > > > environment if you scan one side you will also have to scan the
> > other.
> > > > This table has a pretty large number of records, so I'd like to
> > figure
> > > > out what this means. Any ideas? Thanks.
> > > >
> > > >
> > > >
> > > > DC
> > > >
> > > >
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> > > >
> > > > <p class=MsoNormal><font size=2 face=Arial><span style='font-
> > > size:10.0pt;
> > > > font-family:Arial'>We’re running IDS 9.4.FC5 on AIX 5.2. I
> > have a
> > > table
> > > > that is fragmented by round robin in two dbspaces. It does have
> > rowids
> > > (not my
> > > > decision), and a number of indices. I’ve been noticing
that
> > the
> > > onstat –g
> > > > ppf output for the two partitions have wildly different numbers
of
> > > sequential
> > > > scans. Today, for instance, one partition has 11,000 or so, the
> > other
> > > has 2.
> > > > How does that make any sense? Surely in a round robin
environment if
> > you
> > > scan
> > > > one side you will also have to scan the other. This table has a
> > pretty
> > > large
> > > > number of records, so I’d like to figure out what this
means.
> > Any
> > > ideas?
> > > > Thanks.<o:p></o:p></span></font></p>
> > > >
> > > > <p class=MsoNormal><font size=2 face=Arial><span style='font-
> > > size:10.0pt;
> > > > font-family:Arial'><o:p> </o:p></span></font></p>
> > > >
> > > > <p class=MsoNormal><font size=2 face=Arial><span style='font-
> > > size:10.0pt;
> > > > font-family:Arial'>DC<o:p></o:p></span></font></p>
> > > >
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