same query on 2 Dbs, different explain plan

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Would there be any reason why the same query on two different databases with the same data and indexes would have explain-plans that are so different??

It is obvious why one runs in 100 msecs and the other takes 3secs, but I caqnnot figure out why one starts with BILLING_PERIOD and the other doesn't. Then you have the whole FULL table access on the second as well.

The tables have been analyzed.
I am confused.

Operation	Object Name	Rows	Bytes	Cost	TQ	In/Out	PStart	PStop

SELECT STATEMENT Hint=CHOOSE		1  	 	238  	 	      	             	 
  SORT GROUP BY		1  	177  	238  	 	      	             	 
    TABLE ACCESS BY INDEX ROWID	METER_NORMALIZATION_CONTROL	61 K	954 K	217  	 	      	             	 
      NESTED LOOPS		1  	177  	223  	 	      	             	 
        NESTED LOOPS		1  	161  	6  	 	      	             	 
          MERGE JOIN CARTESIAN		1  	126  	5  	 	      	             	 
            NESTED LOOPS		1  	66  	3  	 	      	             	 
              NESTED LOOPS		1  	46  	2  	 	      	             	 
                TABLE ACCESS BY INDEX ROWID	ACCOUNT	1  	18  	1  	 	      	             	 
                  INDEX UNIQUE SCAN	ACC_PREM_ORG_PK	190  	 	 	 	      	             	 
                TABLE ACCESS BY INDEX ROWID	CUSTOMER	1  	28  	1  	 	      	             	 
                  INDEX UNIQUE SCAN	CUST_CUST_PK	190  	 	 	 	      	             	 
              INDEX RANGE SCAN	ACC_DEV_ACC_DEV_PK	1  	20  	1  	 	      	             	 
            BUFFER SORT		1  	60  	4  	 	      	             	 
              TABLE ACCESS BY INDEX ROWID	BILLING_PERIOD	1  	60  	2  	 	      	             	 
                INDEX RANGE SCAN	BIL_PRD_ACC_RTPLN_STDT_PK	1  	 	1  	 	      	             	 
          TABLE ACCESS BY INDEX ROWID	RATE_PLAN	2  	70  	1  	 	      	             	 
            INDEX UNIQUE SCAN	RP_ORG_RP_PK	13  	 	 	 	      	             	 
        INDEX RANGE SCAN	METER_NRM_NRM_PK	317  	 	3  	 	      	             	 




Operation	Object Name	Rows	Bytes	Cost	TQ	In/Out	PStart	PStop

SELECT STATEMENT Hint=CHOOSE		1  	 	191  	 	      	             	 
  SORT GROUP BY		1  	350  	191  	 	      	             	 
    TABLE ACCESS BY INDEX ROWID	BILLING_PERIOD	1  	60  	2  	 	      	             	 
      NESTED LOOPS		1  	350  	181  	 	      	             	 
        MERGE JOIN CARTESIAN		1  	290  	179  	 	      	             	 
          NESTED LOOPS		1  	205  	178  	 	      	             	 
            NESTED LOOPS		61 K	7 M	178  	 	      	             	 
              NESTED LOOPS		1  	116  	2  	 	      	             	 
                TABLE ACCESS BY INDEX ROWID	ACCOUNT	1  	73  	1  	 	      	             	 
                  INDEX RANGE SCAN	ACC_DR_RES_TYPE_IX	1  	 	2  	 	      	             	 
                TABLE ACCESS BY INDEX ROWID	CUSTOMER	1  	43  	1  	 	      	             	 
                  INDEX UNIQUE SCAN	CUST_CUST_PK	409  	 	 	 	      	             	 
              TABLE ACCESS FULL	METER_NORMALIZATION_CONTROL	61 K	953 K	176  	 	      	             	 
            INDEX UNIQUE SCAN	ACC_DEV_ACC_DEV_PK	1  	73  	 	 	      	             	 
          BUFFER SORT		1  	85  	179  	 	      	             	 
            TABLE ACCESS BY INDEX ROWID	RATE_PLAN	1  	85  	1  	 	      	             	 
              INDEX RANGE SCAN	RP_ORG_RP_PK	1  	 	1  	 	      	             	 
        INDEX RANGE SCAN	TEMP_BP	1  	 	1

query:

SELECT  
         bp.org_id AS org_id, bp.svc_type_cd AS svc_type_cd, 
         bp.cust_id AS cust_id, bp.prem_seq_nbr AS prem_seq_nbr, 
         c.cust_tz_cd AS cust_tz_cd, a.rt_cmpr_cd AS account_rt_cmpr_cd, 
         bp.start_dt AS start_dt, bp.end_dt AS end_dt, 
         bp.est_usage_nbr AS est_usage, bp.est_cost_amt AS est_cost, 
         bp.bill_usage_nbr AS bill_usage, bp.bill_cost_amt AS bill_cost, 
         rp.org_id AS rp_org_id, rp.svc_type_cd AS rp_svc_type_cd, 
         rp.rate_plan_cd AS rp_rate_plan_cd, rp.rt_cmpr_cd AS rp_rt_cmpr_cd, 
         rp.rate_plan_type_cd AS rp_rate_plan_type_cd, 
         MIN(mnc.erlst_rdng_dt) AS earliest_norm_dt 
    FROM BILLING_PERIOD bp, 
         CUSTOMER c, 
         ACCOUNT a, 
         RATE_PLAN rp, 
         ACCOUNT_DEVICE ad, 
         METER_NORMALIZATION_CONTROL mnc 
   WHERE bp.org_id = 'ME' 
     AND bp.svc_type_cd = 'E' 
     AND bp.cust_id = '064014442500' 
     AND bp.prem_seq_nbr = '1' 
     AND bp.bill_usage_nbr IS NULL 
     AND bp.bill_cost_amt IS NULL 
     AND bp.est_usage_nbr IS NULL 
     AND bp.est_cost_amt IS NULL 
     AND c.org_id = bp.org_id 
     AND c.cust_id = bp.cust_id 
     AND a.org_id = bp.org_id 
     AND a.svc_type_cd = bp.svc_type_cd 
     AND a.cust_id = bp.cust_id 
     AND a.prem_seq_nbr = bp.prem_seq_nbr 
     AND rp.org_id = bp.org_id 
     AND rp.svc_type_cd = bp.svc_type_cd 
     AND rp.rate_plan_cd = bp.rate_plan_cd 
     AND ad.org_id = bp.org_id 
     AND ad.svc_type_cd = bp.svc_type_cd 
     AND ad.cust_id = bp.cust_id 
     AND ad.prem_seq_nbr = bp.prem_seq_nbr 
     AND mnc.org_id = ad.org_id 
     AND mnc.device_id = ad.device_id 
GROUP BY bp.org_id, 
         bp.svc_type_cd, 
         bp.cust_id, 
         bp.prem_seq_nbr, 
         c.cust_tz_cd, 
         a.rt_cmpr_cd, 
         bp.start_dt, 
         bp.end_dt, 
         bp.est_usage_nbr, 
         bp.est_cost_amt, 
         bp.bill_usage_nbr, 
         bp.bill_cost_amt, 
         rp.org_id, 
         rp.svc_type_cd, 
         rp.rate_plan_cd, 
         rp.rt_cmpr_cd, 
         rp.rate_plan_type_cd; 

[Cookies]

ah!

got it working with this:
CREATE INDEX temp_mnc
ON METER_NORMALIZATION_CONTROL (org_id, device_id, erlst_rdng_dt)
NOLOGGING TABLESPACE INDX;

thanks for reading.