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From:J S Date:July 14 2004 6:20pm
Subject:Re: do i need an index for this?
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Thanks for your reply. Can I just check my syntax is right for creating the 
key?

CREATE INDEX urlindex ON internet_usage (time);

I ran this before but got an error 27 (eventhough the filesize ulimit was 
set to unlimited). So just wondered if I was using the wrong syntax?

JS.

>
>In the last episode (Jul 14), J S said:
> > I want to find the earliest and latest times in the time column of my
> > table internet_usage:
> >
> > +--------------+----------------------+------+-----+---------+-------+
> > | Field        | Type                 | Null | Key | Default | Extra |
> > +--------------+----------------------+------+-----+---------+-------+
> > | time         | timestamp(14)        | YES  |     | NULL    |       |
> > +--------------+----------------------+------+-----+---------+-------+
> >
> > So far there are 324936160 rows. If I do :
> >
> > SELECT MIN(time) as earliest, MAX(time) as latest from internet_usage;
> >
> > I can see the query is going to run for a long time. Do I have to
> > create an index on time to speed this up or is there another way of
> > doing it?
>
>Most definitely.  An index will make that query almost instantaneous.
>Mysql won't even have to hit the table at all, and just has to look at
>the first and last index blocks.
>
>--
>	Dan Nelson
>	dnelson@stripped
>
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Thread
do i need an index for this?J S14 Jul
  • Re: do i need an index for this?Dan Nelson14 Jul
  • Re: do i need an index for this?Justin Swanhart14 Jul
Re: do i need an index for this?J S14 Jul
  • Re: do i need an index for this?Dan Nelson14 Jul
  • Re: do i need an index for this?John Larsen14 Jul
    • Re: do i need an index for this?Dan Nelson14 Jul
Re: do i need an index for this?J S14 Jul