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

[Heiko G.]

Hi,

thc for your answer, i tried what u suggested and now i *only* have to life with the temporary table. Is there some easy Rule when mysql has to use file sorts or temp tables ?! I have a similar problem with som eother table where it scans the whole table, no index is used (tried to use a index for (xsite,ysizr,gid), nor Do I use a join :( I dont understand why mysql has to scan the whole table to simple fetch one record per (gid)

SELECT name, gid, xsize, ysize
FROM sc_pictures
WHERE xsize > ysize
GROUP BY gid

table  type  possible_keys  key  key_len  ref  rows  Extra  
sc_pictures ALL NULL NULL NULL NULL 38231 Using where; Using temporary; Using filesort

It seems to me this is the same problem as in my other query. I use GROUP but no MAx, MIN etc..The reason is, I simple want (name, gid, xsize, ysize) of *any* picture where x > y , and since I only want one Record per gallery (gid) I used this GROUP by...i had no problems with it so far...at least i did not notice anything, but this Query takes 0.08 seconds, if i remove the group it runs for 0.0002 seconds...I will try to find some workaround

will try some stuff
Thx again Guys!!

Heiko