Question regarding selecting from a fragmented table

Hi all I have a table which is fragmented by date, year to day. When I query this table using the fragment expression as the where clause of my select statement Informix still searches all fragments. Should it not just access the one fragment. Informix version 9.21.UC6 running on Solaris 8. Any ideas? QUERY: ------ select network_id, fragment_date from gproc_statistics where (extend (fragment_date, year to day) = datetime(2004-03-30) year to day) Estimated Cost: 11783 Estimated # of Rows Returned: 25946 1) omcadmin.gproc_statistics: SEQUENTIAL SCAN (Serial, fragments: ALL) Filters: EXTEND (omcadmin.gproc_statistics.fragment_date ,year to day) = datetime(2004-03-30) year to day Table definition:- create table "omcadmin".gproc_statistics ( network_id integer not null constraint "omcadmin".cnn_gpr_stats_054, time_id integer not null constraint "omcadmin".cnn_gpr_stats_055, fragment_date datetime year to minute not null , cpu_usage_mean float, cpu_usage_min smallint, cpu_usage_max smallint ) fragment by expression (EXTEND (fragment_date ,year to day) = datetime(2004-03-22) year to day ) in omc_db_sp2 , (EXTEND (fragment_date ,year to day) = datetime(2004-03-23) year to day ) in omc_db_sp1 , (EXTEND (fragment_date ,year to day) = datetime(2004-03-24) year to day ) in omc_db_sp11 , (EXTEND (fragment_date ,year to day) = datetime(2004-03-25) year to day ) in omc_db_sp10 , (EXTEND (fragment_date ,year to day) = datetime(2004-03-26) year to day ) in omc_db_sp9 , (EXTEND (fragment_date ,year to day) = datetime(2004-03-27) year to day ) in omc_db_sp8 , (EXTEND (fragment_date ,year to day) = datetime(2004-03-28) year to day ) in omc_db_sp7 , (EXTEND (fragment_date ,year to day) = datetime(2004-03-29) year to day ) in omc_db_sp6 , (EXTEND (fragment_date ,year to day) = datetime(2004-03-30) year to day ) in omc_db_sp5 , (EXTEND (fragment_date ,year to day) = datetime(2004-03-31) year to day ) in omc_db_sp4 , (EXTEND (fragment_date ,year to day) = datetime(2004-04-01) year to day ) in omc_db_sp3 , remainder in omc_db_sp12 extent size 64512 next size 13312 lock mode row;