Re: Multiple table entries? - Mailing list pgsql-general

From Greg Stark
Subject Re: Multiple table entries?
Date
Msg-id 407d949e0908231049h5d1911d0qa49f8ccf18833282@mail.gmail.com
Whole thread Raw
In response to Re: Multiple table entries?  (Greg Stark <gsstark@mit.edu>)
Responses Re: Multiple table entries?
List pgsql-general
On Sun, Aug 23, 2009 at 6:23 PM, Greg Stark<gsstark@mit.edu> wrote:
> On Sun, Aug 23, 2009 at 5:37 PM, Jeff Ross<jross@wykids.org> wrote:
>>
>> pg_clog is 32K.  I've put it at http://www.openvistas.net/pg_clog
>
> Sorry, I'm getting a 404

For what it's worth this is what the heap dump shows. I don't
understand why you're seeing these tuples show up if they're all
properly marked as updated and XMAX_COMMITTED.

The last tuple is marked strangely I think. I don't think it's
supposed to have XMAX_INVALID if xmax is 0 but I could be wrong. Also,
I don't understand why it's marked as UPDATED if ctid and xmax aren't
set.

Could you also send
select (h).* from (select  page_header(get_raw_page('pg_namespace',0))
as h) as x;

I'm wondering if the page allvisible flag is set. The visibility map
is one of the few 8.4 patches which impact transaction visibility.


lp    lp_off    flags    lp_len    t_xmin    t_xmax    field3    t_ctid    t_info2    t_info
3    7616    1    141    2    897    0    (0,6)    16387    9482
HOT_UPDATED,                  UPDATED, XMAX_COMMITTED, XMIN_COMMITTED

6    7340    1    129    897    898    0    (0,7)    -16381    9482
HOT_UPDATED, HEAP_ONLY_TUPLE, UPDATED, XMAX_COMMITTED, XMIN_COMMITTED

7    7220    1    117    898    899    0    (0,9)    -16381    9482
HOT_UPDATED, HEAP_ONLY_TUPLE, UPDATED, XMAX_COMMITTED, XMIN_COMMITTED

9    7088    1    129    899    900    0    (0,10)    -16381    9482
HOT_UPDATED, HEAP_ONLY_TUPLE, UPDATED, XMAX_COMMITTED, XMIN_COMMITTED

10    6944    1    141    900    0    0    (0,10)    -32765    10506
 UPDATED, XMAX_INVALID,   XMIN_COMMITTED




--
greg
http://mit.edu/~gsstark/resume.pdf

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