Re: [HACKERS] Re: PD_ALL_VISIBLE flag was incorrectly set happend during repeatable vacuum

On 12.01.2011 06:21, Fujii Masao wrote:
> On Sat, Dec 25, 2010 at 2:09 PM, Maxim Boguk<maxim(dot)boguk(at)gmail(dot)com> wrote:
>> While I trying create reproducible test case for BUG #5798 I
>> encountered very strange effect on two of my servers (both servers
>> have same hardware platform/OS (freebsd 7.2) and PostgreSQL 8.4.4).
>>
>> Very simple test table created as:
>> CREATE TABLE test (id integer);
>> INSERT INTO test select generate_series(0,10000);
>>
>> And I trying repeateble vacuum of that table with script:
>> perl -e "foreach (1..100000) {system \"psql -d test -h -c 'vacuum test'\";}"
>>
>> And once per like an minute (really random intervals can be 5 minutes
>> without problems can be 3 vacuum in row show same error) I getting
>> next errors:
>> WARNING: PD_ALL_VISIBLE flag was incorrectly set in relation "test" page 1
>> ...
>> WARNING: PD_ALL_VISIBLE flag was incorrectly set in relation "test"
>> page 30 for all pages of the relation.

Oh, interesting. This is the first time anyone can reliably reproducible
that. I can't reproduce that on my laptop with that script, though, so
I'm going to need your help to debug this.

Can you compile PostgreSQL with the attached patch, and rerun the test?
It will dump the pages with incorrectly set flags to files in /tmp/, and
adds a bit more detail in the WARNING. Please run the test until you
get those warnings, and tar up the the created "/tmp/pageimage*" files,
and post them along with the warning generated.

We'll likely need to go back and forth a few times with various
debugging patches until we get to the heart of this..

--
Heikki Linnakangas
EnterpriseDB http://www.enterprisedb.com