Which index is fastest

Hi, having the table: create table orders (company smallint, customer char(6), num_order integer, ... ) Which index is fastest in order to find ONE row ? create index orders_1 on order (company, customer, num_order); or create index orders_1 on order (num_order, customer, company); and doing: select * from orders where company = 1 and customer = "0001" and num_order = 1000 for few companys, and lots of customer and orders ... Thanks, Thanks a lot, Manel Falcó SEMIC, S.A. Lleida-Catalonia-Spain-Europe ----------------------------------------------------- Informix version: Informix SE 5.07 / RDS 4.x & 4J's Operating system: Unix SCO V 5.04 -----------------------------------------------------

The easiest way for YOU to find out is running the query after using the SET EXPLAIN ON command SET EXPLAIN ON;query ... This will generate a sqexplain.out file that will contain information you can use to make your own decision. Don't forget that running Update Statistics should be performed after adding the index you are trying out. Take care. Clifton Manel Falc' wrote in message <36c41fc1.15758373@news.bcn.ttd.net>... >Hi, > >having the table: > > create table orders > (company smallint, > customer char(6), > num_order integer, > ... > )> >Which index is fastest in order to find ONE row ? > > create index orders_1 on order (company, customer, num_order);> or > create index orders_1 on order (num_order, customer, company);> >and doing: > select * from orders > where company = 1 and customer = "0001" and num_order = 1000> >for few companys, and lots of customer and orders ... > >Thanks, > >Thanks a lot, > >Manel Falc' >SEMIC, S.A. >Lleida-Catalonia-Spain-Europe >----------------------------------------------------- >Informix version: Informix SE 5.07 / RDS 4.x & 4J's >Operating system: Unix SCO V 5.04 >-----------------------------------------------------