Re: [BUGS] SELECT "bug"?
| От | Tom Lane |
|---|---|
| Тема | Re: [BUGS] SELECT "bug"? |
| Дата | |
| Msg-id | 9811.948492996@sss.pgh.pa.us обсуждение |
| Ответ на | SELECT "bug"? (The Hermit Hacker <scrappy@hub.org>) |
| Список | pgsql-bugs |
The Hermit Hacker <scrappy@hub.org> writes:
> select count(1) from webhit_details_formatted where counter_id = 1;
> [ hangs, then crashes when try to cancel ]
Wow, how'd that escape notice for this long?
play=> create table webhit_details_formatted (counter_id int);
CREATE
play=> select count(1) from webhit_details_formatted where counter_id = 1;
pqReadData() -- backend closed the channel unexpectedly.
Mine just crashes immediately, no waiting.
The good news is that current sources don't seem to have the problem.
> Under Oracle, doing the "SELECT count(1)..." is faster then doing "SELECT
> count(*)..." (supposedly), since it doesn't have to retrieve all the
> information, only count how many records match the WHERE clause ...
Under Postgres, there's no difference --- in fact, the parser currently
converts count(*) into count(1) ;-)
regards, tom lane
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