RE: Fastest way to get table records' number

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> > > At 10:35 AM -0400 3/19/08, Nathan Nobbe wrote:
> > > >On Wed, Mar 19, 2008 at 9:42 AM, Andrew Ballard <aballard@xxxxxxxxx>
> > wrote:
> > > >
> > > >>  That works; I'm just wondering why you went with a count
> on an 'ID'
> > column
> > > >>  rather than COUNT(*).
> > > >
> > > >
> > > >ouch, it looks like im horribly wrong :O
> > > >mysql> select count(*) from table;
> > > >+----------+
> > > >| count(*) |
> > > >+----------+
> > > >|   361724 |
> > > >+----------+
> > > >1 row in set (0.90 sec)
> > > >
> > > >mysql> select count(id) from table;
> > > >+------------+
> > > >| count(did) |
> > > >+------------+
> > > >|     361724 |
> > > >+------------+
> > > >1 row in set (4.56 sec)
> > > >
> > > >-nathan
> > >
> > > That surprised me as well.
> > >
> > > I thought that (*) meant "look up everything" and would have figured
> > > that (id) would have been quicker.
> > >
> > >
> >
> > You generally want to explicitly specify column names rather than
> > using SELECT *, because it returns everything even if you don't need
> > it. But for aggregate COUNT, I'm not surprised by the results Nathan
> > got.
> >

> what about SELECT MAX(id) FROM table :)

But that's not the same thing. If any rows have been deleted, then this
would give the wrong answer.

Edward


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