Simple Query - No Join - But Temp. Table and file Sort :(

[Heiko G.]

Hi All,

maybe can explain to my why mysql uses filesort and temp. table for this simple query:

SELECT e.evdate, e.lockey, e.loc
FROM sc_events e
WHERE e.evdate >=1161428363
GROUP BY e.lockey

This table looks like:

Feld Typ Attribute Null Standard Extra Aktion
id int(11) Nein auto_increment
lockey varchar(10) Nein
loc varchar(255) Nein
descr text Nein
image varchar(10) Nein
www varchar(200) Nein
title varchar(255) Nein
evdate bigint(10) Nein 0
evdate_end bigint(10) Nein 0
dj varchar(200) Nein
style varchar(60) Nein 0
entrmin varchar(4) Nein
entrmax varchar(4) Nein
owner int(5) Nein 0

Indexes:

Name Typ Kardinalität Aktion Feld
PRIMARY PRIMARY 2985 id
evdate_end INDEX 2985 evdate_end
loc
evdate_2 INDEX 2985 evdate
lockey
loc

..and explain shows me something like this:

table type possible_keys key key_len ref rows Extra
e index evdate_2 evdate_2 8 NULL 2985 Using where; Using index; Using temporary; Using filesort

Can i change the index, or th query to get rid of the filsort and temp table here ? Sorry for Cut & Paste, but it seems I cant use <pre> tags here :(

Thx in advance
Heiko