Re: postgresql v11.1 Segmentation fault: signal 11: by running SELECT... JIT Issue?

pabloa98 <pabloa98(at)gmail(dot)com> writes:
> I just migrated our databases from PostgreSQL version 9.6 to version 11.1.
> We got a segmentation fault while running this query:

> SELECT f_2110 as x FROM baseline_denull
> ORDER BY eid ASC
> limit 500
> OFFSET 131000;

> the table baseline_denull has 1765 columns, mainly numbers, like:

Hm, that sounds like it matches this recent bug fix:

Author: Andres Freund <andres(at)anarazel(dot)de>
Branch: master [b23852766] 2018-11-27 10:07:03 -0800
Branch: REL_11_STABLE [aee085bc0] 2018-11-27 10:07:43 -0800

Fix jit compilation bug on wide tables.

The function generated to perform JIT compiled tuple deforming failed
when HeapTupleHeader's t_hoff was bigger than a signed int8. I'd
failed to realize that LLVM's getelementptr would treat an int8 index
argument as signed, rather than unsigned. That means that a hoff
larger than 127 would result in a negative offset being applied. Fix
that by widening the index to 32bit.

Add a testcase with a wide table. Don't drop it, as it seems useful to
verify other tools deal properly with wide tables.

Thanks to Justin Pryzby for both reporting a bug and then reducing it
to a reproducible testcase!

Reported-By: Justin Pryzby
Author: Andres Freund
Discussion: https://postgr.es/m/20181115223959.GB10913@telsasoft.com
Backpatch: 11, just as jit compilation was

This would result in failures on wide rows that contain some null
entries. If your table is mostly-not-null, that would fit the
observation that it only crashes on a few rows.

Can you try REL_11_STABLE branch tip and see if it works for you?

regards, tom lane