Re: sysmaster question
That is the GOOD number! :-)
Frank
On 1/25/07, Jack Parker <jack.parker4@verizon.net> wrote:
>
> My bad. My script is pulling the wrong value for page reads from
> syschkio.
>
> The actual number is 20 million page reads from syschkio.
>
> j.
> -----Original Message-----
> *From:* informix-list-bounces@iiug.org [mailto:
> informix-list-bounces@iiug.org]*On Behalf Of *Jack Parker
> *Sent:* Thursday, January 25, 2007 5:29 PM
> *To:* FRANK
> *Cc:* Informix-List@Iiug. Org
> *Subject:* RE: sysmaster question
>
> create table "informix".message
> (
> msg_id serial not null ,
> subject char(60),
> msg_text text,
> msg_date_time char(30),
> src_id char(20)
> ) extent size 16 next size 16 lock mode page;
> revoke all on "informix".message from "public";>
> no storage clause. no indices.
>
> j.
>
> -----Original Message-----
> *From:* FRANK [mailto:yunyaoqu@gmail.com]
> *Sent:* Thursday, January 25, 2007 5:03 PM
> *To:* Jack Parker
> *Cc:* Informix-List@Iiug. Org
> *Subject:* Re: sysmaster question
>
> Jack,
>
> What is your table definition (dbschema -d xx -t yy -ss) ?
>
> Frank
>
> On 1/25/07, Jack Parker < jack.parker4@verizon.net> wrote:
> >
> > Yes, it is in one chunk.
> >
> > Here is the table info I gather:
> >
> > === Most Physically Active Tables ===
> >
> >
> > Table: cdi:message Created: 01/18/2007 Size: 0.35 GB
> > Pagesize: 2048 Allocated: 186376 Used: 185935 Data:
> > 16889
> > Pgs Free: 441 0.0024%
> > Rowsize: 170 Columns: 5 Keys: 0
> > 1st Ext: 8 Next Ext: 16
> >
> > Other info from Flags:
> > Page level locking
> >
> > Percent of entire engine activity:
> > Isam Ops: 0.29% Buffer Ops: 1.09% Page Ops: 88.76%
> >
> > Rows according to SMI: 185778 Rows according to Stats 185778
> >
> > Chunk: 2 dbspace: dbsp1 file: /opt/informix/dev/dbsp1
> > Reads: 18364082 Writes: 20129981 PgReads: 3560744 PgWrites:
> > 5811620
> > Pagesize: 2048
> > Avg Rows/Page: 2 Avg Freeptr: 1667 Avg Empty Bytes: 367
> > Avg Extent size: 31062 Extents this chk: 6
> >
> > Number of extents: 6
> >
> > Pages:
> > Room for rows: 1
> > Blob semi-full: 1
> > Idx/Bitmap: 47
> > Blob Full: 97088
> > Full: 16888
> > Blob Very Full: 71910
> >
> > Locks Mode: Page
> > Requests: 9307658 Waits: 0 Deadlocks: 0 Lock Time outs: 0
> >
> > Total Activity:
> > Sequential Scans: 3
> > Isam Reads: 216838 Writes: 3426054 Rewrites: 0 Deletes: 0
> > Buffer Reads: 19749173 Writes: 17061814
> > Page Reads: 4246956 Writes: 3443422
> > Buffer/Isam Reads: 91.08 Buffer/Isam Writes: 4.98
> > Page/Isam Reads: 19.59 Page/Isam Writes: 1.01
> >
> >
> > -----Original Message-----
> > From: FRANK [mailto:yunyaoqu@gmail.com]
> > Sent: Thursday, January 25, 2007 4:16 PM
> > To: Jack Parker
> > Cc: Informix-List@Iiug. Org
> > Subject: Re: sysmaster question
> >
> >
> > Sorry, in one chunk. Frank
> >
> >
> > On 1/25/07, FRANK <yunyaoqu@gmail.com> wrote:
> > HI, Jack,
> >
> > Is this table fragmented to more than one chunk?
> >
> > Frank
> >
> >
> >
> >
> > On 1/25/07, Jack Parker < jack.parker4@verizon.net> wrote:
> >
> > poking about.
> >
> > I have a table, in a single dbspace, in a single chunk. (Cooked).
> >
> > According to sysptprof, there have been 4.2 million page reads against
> > the
> > table.
> >
> > According to syschkio, there have been 3.6 million pages read from the
> > chunk.
> >
> > Obviously this is a discrepancy, how is it getting resolved? A request
> > is
> > made to disk to read a page, and the page has already been read? Then
> > why
> > doesn't it count in bufreads?
> >
> > This particular table accounts for 88% of my i/o against this disk, so
> > add
> > another 400K or so page reads to the 4.2 million number.
> >
> > Page writes seem to be more consistent with what I'd expect.
> >
> > cheeers
> > j.
> >
> > _______________________________________________
> > Informix-list mailing list
> > Informix-list@iiug.org
> > http://www.iiug.org/mailman/listinfo/informix-list
> >
> >
>