Обсуждение: index doesn't work for null?

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index doesn't work for null?

От
Alex Pilosov
Дата:
I have a bit of a problem:

'select from xx where field=null' will always result in seq scan even when
there's a [btree] index on the field.

Is this a known issue?

-alex


Re: index doesn't work for null?

От
Per-Olof Pettersson
Дата:
Hi Alex

I have no idea if it is a known issue.
Though "field=null" is not allowed in standard SQL.
The correct statement should be "select from xx where field IS NULL;".

Perhaps it will be handled better (or not).

Best regards
Per-Olof Pettersson

>>>>>>>>>>>>>>>>>> Original Message <<<<<<<<<<<<<<<<<<

On 2001-05-16, 00:21:34, alex@pilosoft.com (Alex Pilosov) wrote regarding
index doesn't work for null?:


> I have a bit of a problem:

> 'select from xx where field=null' will always result in seq scan even
when
> there's a [btree] index on the field.

> Is this a known issue?

> -alex


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Re: Re: index doesn't work for null?

От
Alex Pilosov
Дата:
Sorry bout that. Actually query does 'is null', I made a mistake in
my post.

-alex

On Tue, 15 May 2001, Per-Olof Pettersson wrote:

> Hi Alex
>
> I have no idea if it is a known issue.
> Though "field=null" is not allowed in standard SQL.
> The correct statement should be "select from xx where field IS NULL;".
>
> Perhaps it will be handled better (or not).
>
> Best regards
> Per-Olof Pettersson
>
> >>>>>>>>>>>>>>>>>> Original Message <<<<<<<<<<<<<<<<<<
>
> On 2001-05-16, 00:21:34, alex@pilosoft.com (Alex Pilosov) wrote regarding
> index doesn't work for null?:
>
>
> > I have a bit of a problem:
>
> > 'select from xx where field=null' will always result in seq scan even
> when
> > there's a [btree] index on the field.
>
> > Is this a known issue?
>
> > -alex
>
>
> > ---------------------------(end of broadcast)---------------------------
> > TIP 6: Have you searched our list archives?
>
> > http://www.postgresql.org/search.mpl
>
> ---------------------------(end of broadcast)---------------------------
> TIP 1: subscribe and unsubscribe commands go to majordomo@postgresql.org
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