Re: LIKE query on indexes

Поиск
Список
Период
Сортировка
От mark@mark.mielke.cc
Тема Re: LIKE query on indexes
Дата
Msg-id 20060221174048.GA8108@mark.mielke.cc
обсуждение исходный текст
Ответ на LIKE query on indexes  ("Ibrahim Tekin" <itekin@gmail.com>)
Ответы Re: LIKE query on indexes  ("Ibrahim Tekin" <itekin@gmail.com>)
Список pgsql-performance
On Tue, Feb 21, 2006 at 05:57:12PM +0200, Ibrahim Tekin wrote:
> i have btree index on a text type field. i want see rows which starts with
> certain characters on that field. so i write a query like this:
>     SELECT * FROM mytable WHERE myfield LIKE 'john%'
> since this condition is from start of the field, query planner should use
> index to find such elements but explain command shows me it will do a
> sequential scan.
> is this lack of a feature or i am wrong somewhere?

Is the query fast enough? How big is your table? What does explain
analyze select tell you?

Cheers,
mark

--
mark@mielke.cc / markm@ncf.ca / markm@nortel.com     __________________________
.  .  _  ._  . .   .__    .  . ._. .__ .   . . .__  | Neighbourhood Coder
|\/| |_| |_| |/    |_     |\/|  |  |_  |   |/  |_   |
|  | | | | \ | \   |__ .  |  | .|. |__ |__ | \ |__  | Ottawa, Ontario, Canada

  One ring to rule them all, one ring to find them, one ring to bring them all
                       and in the darkness bind them...

                           http://mark.mielke.cc/


В списке pgsql-performance по дате отправления:

Предыдущее
От: Scott Marlowe
Дата:
Сообщение: Re: LIKE query on indexes
Следующее
От: "Ibrahim Tekin"
Дата:
Сообщение: Re: LIKE query on indexes