Re: index structure for 114-dimension vector

Список
Период
Сортировка
От Mark Kirkwood
Тема Re: index structure for 114-dimension vector
Дата
Msg-id 46294FEB.9010909@paradise.net.nz
обсуждение исходный текст
Ответ на Re: index structure for 114-dimension vector  (Jeff Davis)
Ответы Re: index structure for 114-dimension vector  (Andrew Lazarus)
Re: index structure for 114-dimension vector  (Arjen van der Meijden)
Список pgsql-performance
Дерево обсуждения
Basic Q on superfluous primary keys  ("Kynn Jones", )
 Re: Basic Q on superfluous primary keys  (Bill Moran, )
  Re: Basic Q on superfluous primary keys  ("Merlin Moncure", )
   Re: Basic Q on superfluous primary keys  ("Craig A. James", )
    Re: Basic Q on superfluous primary keys  ("Merlin Moncure", )
     Re: Basic Q on superfluous primary keys  (Greg Smith, )
      Re: Basic Q on superfluous primary keys  ("Merlin Moncure", )
       Re: Basic Q on superfluous primary keys  ("Craig A. James", )
        Re: Basic Q on superfluous primary keys  (Richard Huxton, )
         Re: Basic Q on superfluous primary keys  (Greg Smith, )
        Re: Basic Q on superfluous primary keys  ("Merlin Moncure", )
         Re: Basic Q on superfluous primary keys  ("Craig A. James", )
        Re: Basic Q on superfluous primary keys  (Jeff Davis, )
       Re: Basic Q on superfluous primary keys  ("Dave Dutcher", )
        Re: Basic Q on superfluous primary keys  ("Merlin Moncure", )
         index structure for 114-dimension vector  (Andrew Lazarus, )
          Re: index structure for 114-dimension vector  (Jeff Davis, )
           Re: index structure for 114-dimension vector  (Mark Kirkwood, )
            Re: index structure for 114-dimension vector  (Andrew Lazarus, )
             Re: index structure for 114-dimension vector  (Mark Kirkwood, )
             Re: index structure for 114-dimension vector  (Tom Lane, )
            Re: index structure for 114-dimension vector  (Arjen van der Meijden, )
          Re: index structure for 114-dimension vector  (C Storm, )
          Re: index structure for 114-dimension vector  ("Alexander Staubo", )
           Re: index structure for 114-dimension vector  (Oleg Bartunov, )
            Re: index structure for 114-dimension vector  (Andrew Lazarus, )
             Re: index structure for 114-dimension vector  ("Alexander Staubo", )
       Re: Basic Q on superfluous primary keys  ("Craig A. James", )
    Re: Basic Q on superfluous primary keys  (Ron Mayer, )
Jeff Davis wrote:
> On Fri, 2007-04-20 at 12:07 -0700, Andrew Lazarus wrote:
>> I have a table with 2.5 million real[] arrays. (They are points in a
>> time series.) Given a new array X, I'd like to find, say, the 25
>> closest to X in some sense--for simplification, let's just say in the
>> usual vector norm. Speed is critical here, and everything I have tried
>> has been too slow.
>>
>> I imported the cube contrib package, and I tried creating an index on
>> a cube of the last 6 elements, which are the most important. Then I
>
> Have you tried just making normal indexes on each of the last 6 elements
> and see if postgresql will use a BitmapAnd to combine them?
>
>

I don't think that will work for the vector norm i.e:

|x - y| = sqrt(sum over j ((x[j] - y[j])^2))


Cheers

Mark

В списке pgsql-performance по дате отправления:

Предыдущее
От: Tom Lane
Дата:
Сообщение: Re: index structure for 114-dimension vector
Следующее
От: cluster
Дата:
Сообщение: Re: FK triggers misused?