I'm not certain how MySQL handles the specific case where some columns
in a record covered by a multi-column index are updated; it may update
the whole index entry, or just part of it, not sure. In any case,
yes, there is some overhead associated with having an index on columns
that get updated.
I agree that individual fields have relatively few possible values -
hopefully, when those are combined in a multi-column index, he will
have a greater number of unique combinations, gaining more out of the
index. That's why I suggested putting stype and Is_id as the first
two fields in the in
Hi!
Try:
set engine_condition_pushdown = on;
explain select ip from ipaddr
where pool='INTERNET' and stype='S' and ls_id=3 and allocated is null
limit 1;
to see if you can push the predicates to improve performance.
BR
-- Martin
Mindaugas wrote:
Hello,
For the Radius server we're using MyS
6 1:28 PM
> To: mysql@lists.mysql.com
> Subject: RE: RE: How to rewrite query
>
> Would it not be best to have the field with the fewest
> repeats (i.e., the
> closest to unique) first, or is that what you meant.
> Bill
>
> On Tue, October 17, 2006 10:12, Jerry Schwartz said:
ilto:[EMAIL PROTECTED]
>> Sent: Tuesday, October 17, 2006 12:05 PM
>> To: Jerry Schwartz
>> Cc: mos; mysql@lists.mysql.com
>> Subject: Re: RE: How to rewrite query
>>
>> I agree that individual fields have relatively few possible values -
>> hopefully, when
Farmington, CT 06032
>
> 860.674.8796 / FAX: 860.674.8341
>
>
>> -Original Message-
>> From: Dan Buettner [mailto:[EMAIL PROTECTED]
>> Sent: Tuesday, October 17, 2006 12:05 PM
>> To: Jerry Schwartz
>> Cc: mos; mysql@lists.mysql.com
>> Subject: Re
> sequential read
> > anyways.
> >
> > Regards,
> >
> > Jerry Schwartz
> > Global Information Incorporated
> > 195 Farmington Ave.
> > Farmington, CT 06032
> >
> > 860.674.8796 / FAX: 860.674.8341
> >
> >
> > &
6 / FAX: 860.674.8341
> -Original Message-
> From: mos [mailto:[EMAIL PROTECTED]
> Sent: Tuesday, October 17, 2006 10:46 AM
> To: mysql@lists.mysql.com
> Subject: Re: How to rewrite query
>
> At 08:34 AM 10/17/2006, you wrote:
>
> > Hello,
> >
>
ington Ave.
Farmington, CT 06032
860.674.8796 / FAX: 860.674.8341
> -Original Message-
> From: mos [mailto:[EMAIL PROTECTED]
> Sent: Tuesday, October 17, 2006 10:46 AM
> To: mysql@lists.mysql.com
> Subject: Re: How to rewrite query
>
> At 08:34 AM 10/17/2006, you wr
At 08:34 AM 10/17/2006, you wrote:
Hello,
For the Radius server we're using MySQL cluster and the following query
looks too slow:
select ip from ipaddr
where pool='INTERNET' and stype='S' and ls_id=3 and allocated is null
limit 1;
Table ipaddr is small (~6MB, 38000 records). Fields in
You should strongly consider adding an index on the fields you're
querying against. Right now, none of the fields in your query are
indexed in the table.
I would try something like this for starters: a multi-column index
against all the fields in the query you showed. If you have other
queries
Mindaugas, can you post the output of
SHOW CREATE TABLE ipaddr;
and
EXPLAIN select ip from ipaddr
where pool='INTERNET' and stype='S' and ls_id=3 and allocated is null
limit 1;
When you say it's too slow, how slow is it? And how fast when it is a
memory table?
Also, which specific version
Hello,
For the Radius server we're using MySQL cluster and the following query
looks too slow:
select ip from ipaddr
where pool='INTERNET' and stype='S' and ls_id=3 and allocated is null
limit 1;
Table ipaddr is small (~6MB, 38000 records). Fields in WHERE clause have
few values and no
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