Re: Selecting large tables gets killed

I found a very simple repro on my machine
postgres=# select x, x, lpad('string', 100, x::text) from
generate_series(1, 10000000) x;
Killed

So this is just about fetching huge data through psql.

But if I reduce the number of rows by 10 times, it gives result without
getting killed.

[ashutosh(at)ubuntu repro]psql -d postgres
psql (9.4devel)
Type "help" for help.

postgres=# select x, x, lpad('string', 100, x::text) from
generate_series(1, 1000000) x;
x | x |
lpad
---------+---------+------------------------------------------------------------------------------------------------------
1 | 1 |
1111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111string

May be each setup has it's own breaking point. So trying with larger number
might reproduce the issue.

I tried to debug it with gdb, but all it showed me was that psql received a
SIGKILL signal. I am not sure why.

On Thu, Feb 20, 2014 at 2:13 PM, amul sul <sul_amul(at)yahoo(dot)co(dot)in> wrote:

> Hi,
>
> I tried reproduce this bug on CENTOS 6.4 as well as on UBUNTU 13.04.
> My Base machine is Window 7 and CentOs, Ubuntu is in VM.
>
> CENTOS :
> [amul(at)localhost postgresql]$ uname -a
> Linux localhost.localdomain 2.6.32-358.6.1.el6.x86_64 #1 SMP Tue Apr 23
> 19:29:00 UTC 2013 x86_64 x86_64 x86_64 GNU/Linux
>
> UBUNTU:
> [amul(at)localhost postgresql]$ uname -a
> Linux localhost.localdomain 2.6.32-358.6.1.el6.x86_64 #1 SMP Tue Apr 23
> 19:29:00 UTC 2013 x86_64 x86_64 x86_64 GNU/Linux
>
>
> I didn't face any kill problem on both VM machine.
> Even by making this table(big_tab) bigger.
> .
> my select output some how as follow
> .
> postgres=# select * from big_tab;
> val | val2 | str
>
>
>
> ----------+----------+------------------------------------------------------------------------------------
> ------------------
> 1 | 1 |
> 11111111111111111111111111111111111111111111111111111111111111111111111111111111111
> 11111111111string
> 2 | 2 |
> 22222222222222222222222222222222222222222222222222222222222222222222222222222222222
> 22222222222string
> .
> .
> <skipped>
>
> And other info
>
> amul(at)amul:~/work/postgresql$ psql postgres
>
> I installed from HEAD(ae5266f25910d6e084692a7cdbd02b9e52800046)
>
>
> I failed to reproduce it, do I missing something?
>
> Regards,
>
> Amul Sul
>

--
Best Wishes,
Ashutosh Bapat
EnterpriseDB Corporation
The Postgres Database Company