how can i improve the performance of this query
Select
item_w.SLR_ID
, count(distinct item_loc.ITEM_ID ) TOTAL_ITEM_SHIP_INTL
from b_views.D_LOC item_loc
,b_views.D_W item_w
,b_views.D_C shpmt_loc
,b_views.D_CNTRIES cntry_1
,b_views.D_CNTRIES cntry_2
Where...