Обсуждение: Re: [HACKERS] function for setting/getting same timestamp during whole transaction

Removing -hackers and adding -general

On Wed, Feb 6, 2013 at 7:26 AM, Miroslav =C5=A0imul=C4=8D=C3=ADk
<simulcik.miro@gmail.com>wrote:

>
>
>
>>  Alternately, you might be able to use a custom GUC from a rather smalle=
r
>> PL/PgSQL function. At transaction start, issue:
>>
>>     set_config('myapp.trigger_time', '', 't');
>>
>
> This is problem with using custom GUC - clearing variable at transaction
> start. Without clearing it's not sufficient solution (see my response to
> Pavel's mail). I don't want to do clearing from application and as far as=
 i
> know there is not "transaction start" trigger.
>

I think you can do it by using 2 GUCs.

Put this at the beginning of your trigger:

if current_setting(my_var.now) !=3D now() then
    -- We're executing this code for the first time in this transaction
    set_config(my_var.now, now())
    set_config(my_var.my_ts, clock_timestamp)
end;
-- Go on happily use my_var.my_ts to stamp your data.

HTH,
--=20
Gurjeet Singh

http://gurjeet.singh.im/