Working with a complex query and trying to get rid of duplicates

Question

I'm working with the following complex query, and I need to
select vin, number, year, make, model, and state from
2007 vehicles in certain models, vin types
2006 vehicles in certain models, vin types
Is there a more efficient way to write this than how I've been writing it?:
select distinct vehicle.vin VIN, unit.STATION_ID STID, unit.EMBEDDED_AREA_CODE||unit.EMBEDDED_PREFIX||lpad(unit.EMBEDDED_RON,4,0)
MIN, unit.AUTHENTICATION_ID AUTHCODE, vehicle.user_veh_desc, veh_model.VEH_MODEL_DESC MODEL, veh_model.VEH_MANUF_YEAR YEAR, acct_veh.STATE STATE
from vehicle
inner join veh_unit on vehicle.vehicle_sak=veh_unit.vehicle_sak
inner join unit on veh_unit.unit_sak=unit.unit_sak
inner join vdu_profile on vdu_profile.vehicle_sak=vehicle.vehicle_sak
inner join vdu_profile_program on vdu_profile_program.VDU_PROFILE_SAK=vdu_profile.VDU_PROFILE_SAK
inner join veh_model on vehicle.VEH_MODEL = veh_model.VEH_MODEL
inner join acct_veh on acct_veh.VEHICLE_SAK = vehicle.VEHICLE_SAK
and vehicle.user_veh_desc like ('%2007%')
AND unit.unit_gen_id >= 36
AND vdu_profile_program.VDU_PROGRAM_SAK = 3
and vdu_profile_program.PREFERENCE_VALUE = 'Y'
and acct_veh.STATE in ('MN','ND','IA')
AND (veh_model.VEH_MODEL_DESC like ('%Vehicle2%')
OR veh_model.VEH_MODEL_DESC like ('%Vehicle3%')
OR veh_model.VEH_MODEL_DESC like ('%Vehicle5%')
OR veh_model.VEH_MODEL_DESC like ('%Vehicle6%')
OR veh_model.VEH_MODEL_DESC like ('%Vehicle7%')
OR veh_model.VEH_MODEL_DESC like ('%Vehicle8%')
OR veh_model.VEH_MODEL_DESC like ('%Vehicle9%'))
and ACCT_VEH.ACCT_VEH_STATUS_ID = 'A'
and (vehicle.vin like ('_______3_________')
or vehicle.vin like ('_______W_________')
or vehicle.vin like ('_______K_________')
or vehicle.vin like ('_______0_________'))
UNION
select distinct vehicle.vin VIN, unit.STATION_ID STID, unit.EMBEDDED_AREA_CODE||unit.EMBEDDED_PREFIX||lpad(unit.EMBEDDED_RON,4,0)
MIN, unit.AUTHENTICATION_ID AUTHCODE, vehicle.user_veh_desc, veh_model.VEH_MODEL_DESC MODEL, veh_model.VEH_MANUF_YEAR YEAR, acct_veh.STATE STATE
from vehicle
inner join veh_unit on vehicle.vehicle_sak=veh_unit.vehicle_sak
inner join unit on veh_unit.unit_sak=unit.unit_sak
inner join vdu_profile on vdu_profile.vehicle_sak=vehicle.vehicle_sak
inner join vdu_profile_program on vdu_profile_program.VDU_PROFILE_SAK=vdu_profile.VDU_PROFILE_SAK
inner join veh_model on vehicle.VEH_MODEL = veh_model.VEH_MODEL
inner join acct_veh on acct_veh.VEHICLE_SAK = vehicle.VEHICLE_SAK
and vehicle.user_veh_desc like ('%2006%')
AND unit.unit_gen_id >= 36
AND vdu_profile_program.VDU_PROGRAM_SAK = 3
and vdu_profile_program.PREFERENCE_VALUE = 'Y'
and acct_veh.STATE in ('MN','ND','IA')
AND (veh_model.VEH_MODEL_DESC like ('%Vehicle1%')
OR veh_model.VEH_MODEL_DESC like ('%Vehicle2%')
OR veh_model.VEH_MODEL_DESC like ('%Vehicle3%')
OR veh_model.VEH_MODEL_DESC like ('%Vehicle4%')
OR veh_model.VEH_MODEL_DESC like ('%Vehicle5%')
OR veh_model.VEH_MODEL_DESC like ('%Vehicle6%')
OR veh_model.VEH_MODEL_DESC like ('%Vehicle7%'))
and ACCT_VEH.ACCT_VEH_STATUS_ID = 'A'
and (vehicle.vin like ('_______Z_________')
or vehicle.vin like ('_______K_________'))

Answer 1

I am not sure how many rows you have in the tables but I am assuming that there would be performance benefits in performing the query only once. You can combine similar coding and use an OR condition for the parts that are different. I left the 'K' vin comparison in both years for readability.
I was not able to fully test my code but I believe that it will work as is. I hope it helps. If you are happier with the UNION you may want to investigate the WITH clause as you can query a subset of data twice, rather than the full data set.
-- Common code 
SELECT DISTINCT
   vehicle.vin,
   unit.station_id stid,
   unit.embedded_area_code || unit.embedded_prefix || LPAD (unit.embedded_ron, 4, 0) MIN,
   unit.authentication_id authcode,
   vehicle.user_veh_desc,
   veh_model.veh_model_desc model,
   veh_model.veh_manuf_year YEAR,
   acct_veh.state
FROM vehicle
INNER JOIN veh_unit           
   ON vehicle.vehicle_sak = veh_unit.vehicle_sak
INNER JOIN unit               
   ON veh_unit.unit_sak = unit.unit_sak
INNER JOIN vdu_profile        
   ON vdu_profile.vehicle_sak = vehicle.vehicle_sak
INNER JOIN vdu_profile_program
   ON vdu_profile_program.vdu_profile_sak = vdu_profile.vdu_profile_sak
INNER JOIN veh_model          
   ON vehicle.veh_model = veh_model.veh_model
INNER JOIN acct_veh           
   ON acct_veh.vehicle_sak = vehicle.vehicle_sak     
AND unit.unit_gen_id >= 36
AND vdu_profile_program.vdu_program_sak = 3
AND vdu_profile_program.preference_value = 'Y'
AND acct_veh.state IN ('MN', 'ND', 'IA')
AND acct_veh.acct_veh_status_id = 'A'
AND
-- Annual code
      (   -- 2006 conditions 
      AND vehicle.user_veh_desc LIKE ('%2007%')
      AND regexp_like(veh_model.veh_model_desc, 'Vehicle[2356789]')
      AND regexp_like(vehicle.vin, '_{7}[3WK0]_{9}')           
   OR
      (   -- 2007 conditions 
      AND vehicle.user_veh_desc LIKE ('%2006%')
      AND regexp_like(veh_model.veh_model_desc, 'Vehicle[1234567]')
      AND regexp_like(vehicle.vin, '_{7}[ZK]_{9}')
   ).