Search Postgresql Archives

Re: Server process crash - Segmentation fault

[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

 



   Could it be related to the OFFSET part of the statement ? I have another query on the same table without OFFSET, which seems to work fine.

 Leif


----- Original Message -----
> Leif Jensen <leif@xxxxxxxxxxx> writes:
> >    Here is a gdb dump of the backtrace at the server process crash.
> >    I have also included the code that generates these calls. As
> >    mentioned below this specific connection has been used many times
> >    before the crash. Also, we are aware of the thread caveat that
> >    only using a connection from one thread at a time. Therefore the
> >    "strange" connection name that includes both the process id and
> >    the thread id. This is for the code to make sure that a
> >    connection is only used in the thread it is meant to.
> 
> Hm. The crash looks like it must be because ActiveSnapshot is null
> (not set). Since we're doing a FETCH, the active snapshot ought to
> be the one saved for the cursor query by DECLARE CURSOR. It looks
> like the problem is that pquery.c only bothers to install that as the
> active snapshot while calling ExecutorRun, but in this stack trace
> we're in ExecutorRewind.
> 
> I wonder if it's a bad idea for ExecReScanLimit to be executing
> user-defined expressions? But it's been like that for awhile,
> and I think we might have a hard time preserving the bounded-sort
> optimization if we didn't do that.
> 
> Anyway the simple fix would be to ensure we install the query
> snapshot as active before calling ExecutorRewind.
> 
> One interesting question is why this issue hasn't been seen before;
> it seems like it'd not be that hard to hit.
> 
> regards, tom lane



[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]
[Index of Archives]     [Postgresql Jobs]     [Postgresql Admin]     [Postgresql Performance]     [Linux Clusters]     [PHP Home]     [PHP on Windows]     [Kernel Newbies]     [PHP Classes]     [PHP Books]     [PHP Databases]     [Postgresql & PHP]     [Yosemite]
  Powered by Linux