Re: Speed of data retrival
Date: Wed, 29 May 2002 23:16:46 GMT
Message-ID: <3CF5615B.44B816B1_at_exesolutions.com>
Niall Litchfield wrote:
> "Daniel Morgan" <dmorgan_at_exesolutions.com> wrote in message
> news:3CF3A073.9957EFE2_at_exesolutions.com...
> > Stjepan Brbot wrote:
> >
> > > What is the difference according to speed of data retrival or any other
> > > aspect of execution speed if one uses more columns in SELECT
> > > SQL-statement?
> > >
> > > Is there any difference in retrival of these two SELECT statements:
> > >
> > > SELECT col1,col2,col3 FROM table1 WHERE col1=4
> > >
> > > and
> > >
> > > SELECT col1,col2 FROM table1 WHERE col1=4
> > >
> > > --
> > >
> > > Stjepan Brbot
> >
> > Immeasureably small.
>
> In general but it depends on the data
>
> select title,date from films where director = 'HITCHCOCK';
>
> will be considerably faster than
>
> select title,date,video_content from films where director = 'HITCHCOCK';
>
> --
> Niall Litchfield
> Oracle DBA
> Audit Commission UK
If by content you mean "BLOB" I whole-heartedly agree.
On the other hand ... SELECT blob_field FROM table is a real non-starter.
Daniel Morgan Received on Thu May 30 2002 - 01:16:46 CEST