Re: [HACKERS] pgbench more operators & functions
| От | Teodor Sigaev |
|---|---|
| Тема | Re: [HACKERS] pgbench more operators & functions |
| Дата | |
| Msg-id | 992df164-6bb0-6a88-1d03-a97d891d715b@sigaev.ru обсуждение исходный текст |
| Ответ на | Re: [HACKERS] pgbench more operators & functions (Fabien COELHO <coelho@cri.ensmp.fr>) |
| Ответы |
Re: [HACKERS] pgbench more operators & functions
|
| Список | pgsql-hackers |
> Here is a rebase after "pow" addition.
Huh, you are fast.
Investigating your patch I found that all arguments of logical AND/OR and CASE
are always evaluated. Seems, it should not be for pair of reasons:
- computing of unneeded args could be too expensive
- computing of unneeded args could complicate scripting code, look:
\set zy 0
\set yz case when :zy = 0 then -1 else (1 / :zy) end
This example will fail although programmer tried to check forbidden value
case when 1>0 then 1 when 1/0 > 0 then 0 else -1 end -- fails too
SQL doesn't evaluate unneeded arguments:
select case when 1>0 then 33 when 1/0 > 0 then -33 else null end;
case
------
33
--
Teodor Sigaev E-mail: teodor@sigaev.ru
WWW: http://www.sigaev.ru/
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