SELECT  ch.bus_unit,
        ch.sys_pltfrm,
        ch.bus_pltfrm,
        ch.CURRENT_RECORD_FLG,
        CH.DIM_PC_ACCT_MGR_MG_ID,
        Ch.dim_cust_hist_mg_id,
        am.ACCT_TERR_NUM,
        am.acct_mgr_empl_id, 
        am.acct_mgr_name, 
        ch.cust_num, 
        ch.cust_name,
        ch.effective_dt,
        ch.expiration_dt,
        LAG(ch.effective_dt,1) OVER (PARTITION BY ch.cust_num ORDER BY ch.effective_dt)AS PREV_date,
        LAG(am.acct_mgr_empl_id,1) OVER (PARTITION BY ch.cust_num ORDER BY ch.effective_dt)AS PREV_AM_ID,
        LAG(am.acct_mgr_name,1) OVER (PARTITION BY ch.cust_num ORDER BY ch.effective_dt)AS PREV_AM
FROM mmsedw.v_dim_customer_hist_mg ch, 
      mmsedw.v_dim_pc_acct_mgr_mg am
WHERE ch.dim_pc_acct_mgr_mg_id=am.dim_pc_acct_mgr_mg_id
and ch.effective_dt between '1-mar-2015' and '31-mar-2015'

left join 

select 
       c.cust_num,
       c.bus_unit,
       c.sys_pltfrm,
       sum(f.ext_sls_pss + f.ext_sls_mms) as annual_Sales,
       sum(f.ext_sell_mrgn_pss + f.ext_mrgn_cogs_rep_mms) as annual_gp         
  from mmsedw.v_fact_sales_mg f,
       mmsedw.v_dim_customer_mg c,
       mmsedw.v_dim_item_mg i,
       mmsedw.v_dim_rebate_type r,
       mmsedw.v_dim_transaction_type_mg t
 where f.dim_cust_mg_id = c.dim_cust_mg_id
       and f.dim_item_mg_id = i.dim_item_mg_id
       and f.dim_rbt_type_id = r.dim_rbt_type_id
       and f.dim_gl_dt_id between 20130401 and 20140331
       and r.rbt_type <> 'N'
       and i.fin_prod_sub_grp_dsc not in ('Flu','Lab Consulting','HIT')
       and f.bus_pltfrm = 'PC'
       and f.dim_transaction_type_mg_id = t.dim_transaction_type_mg_id
       and t.sls_rpt_flg = 'Y'
 group by
        
       c.cust_num,
       c.bus_unit,
       c.sys_pltfrm