Query optimization problem

Hi all,

I have the following table definition:

CREATE TABLE "CONSUM"(
   "ID" Integer NOT NULL,
   "HOTEL" Integer NOT NULL,
   "SERVICE" Integer NOT NULL,
   "SEGMENT" Integer NOT NULL,
   "GUEST" Integer,
   "COMPANY" Fixed (38,0),
   "AGENCY" Fixed (38,0),
   "REPRESENTATIVE" Fixed (38,0),
   "INVOICEDATE" Date,
   "CHARGEDATE" Date,
   "QUANTITY" Fixed (12,2) DEFAULT 0.00,
   "AMOUNT" Fixed (12,2) DEFAULT 0.00,
   "ROOMNIGHTS" Fixed (12,2) DEFAULT 0.00,
   "RATE" Integer,
   "SEASON" Char (1) ASCII,
   "PROCESSDATE" Date,
   PRIMARY KEY ("ID")
)

I also have an UNIQUE INDEX created on column INVOICEDATE.
The table has ~25.000.000 rows.

When I try a query like: 
   SELECT * FROM consum WHERE invoiceDate between '2004-01-01' AND 
'2004-12-31'
it takes very few seconds to show the information using SQLStudio, but 
if I try this other query:
   SELECT * FROM consum WHERE invoiceDate between '2004-01-01' AND 
'2004-12-31' AND rate=9
it take several hours!! to process the information.

What can I do to optimize this kind of queries? Should I create an index 
for each column that I need to query? Or is it better to create an index 
that includes all the columns of the query?


Thank you very much for your help and sorry for my english.



--
MaxDB Discussion Mailing List
For list archives: http://lists.mysql.com/maxdb
To unsubscribe:    http://lists.mysql.com/maxdb?unsub=gcdm-maxdb@xxxxxxxxxxx