Re: query failing with out of memory error message.

On Tue, 29 Jun 2004 22:50:56 -0400, Tom Lane <tgl@sss.pgh.pa.us> wrote:

Thanks!

Where can I find a version of gp_filedump compatible with 7.4?

> "Joe Maldonado" <jmaldonado@webehosting.biz> writes:
>> I have a seemingly corrupt row in a table and wanted to look at it's
>> contents.
>> when I try to query it I get the following...
>
>> db=# select * from some_table offset 411069 limit 1;
>> ERROR:  invalid memory alloc request size 4294967293
>
>> but when I select individual fields within the record I get data.
>
> That's odd ... I'd certainly expect one or the other field of the table
> to show that failure.
>
>> Is there a way to read this row from the datafile to examine it closer?
>
> Select "ctid" from the troublesome row to determine its block and item
> number, then dump out that block with pg_filedump.  If there is data
> corruption it'll usually be possible to see it in the pg_filedump dump.
>
> Another line of attack is to attach to the backend process with gdb and
> set a breakpoint at errfinish (or elog if a pre-7.4 backend), and then
> get a stack trace back from the error report.  This will help narrow
> down exactly where the bogus allocation request is coming from.
>
>             regards, tom lane
>
> ---------------------------(end of broadcast)---------------------------
> TIP 4: Don't 'kill -9' the postmaster



--
--
Joe Maldonado
jmaldonado@webehosting.biz