Slow query

Hi all,

I have a query that counts lines with certain properties, grouped by
day. But the time is stored in seconds, therefore I do it as follows:

EXPLAIN SELECT
received_time as raw_date,
DATE_FORMAT(FROM_UNIXTIME(received_time), '%d. %M %Y') AS format_date,
sum(case when server_state=5 and outcome=1 then 1 else 0 end) as
wu_success,
sum(cpu_time/3600) as cpu_hours,
sum(case when server_state=5 and outcome!=1 and outcome!=4 then 1 else 0
end) as wu_other
FROM result
WHERE received_time>1162277941
GROUP BY format_date DESC
ORDER BY raw_date DESC:

*** row 1 ***
table: result
type: range
possible_keys: idx_received_time
key: idx_received_time
key_len: 4
ref: NULL
rows: 110388
Extra: Using where; Using temporary; Using filesort

That works but the query takes several minutes to complete. Is it
possible to speed it up? The table result holds about 250 000 lines
and it has an index on the received_time column but I'm not sure if
the index really helps in that case.



Thx. Best
Bernahrd