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Message Posted: Thu, 08 Jan 2004 @ 22:50:49 GMT


     
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Subj:   Re: View Performance
 
From:   Ganga Palakattil

Victor,

We have V2R4.1 now. We will be moving to V2R5.1 this month.

I changed the view in the old way as follows:

replace view obc_master.recontacts as
locking table obc_master.lu_obc_job_info for access
locking table obc_master.fa_obc_mdn_mtd for access
locking table obc_master.lu_obc_rcontact_job_addnl_info for access
locking table obc_load.npa_nxx_outbound for access (
  select l.owner_carrier_id as ocid, recjob.location_id as orig,
    (recjob.reporting_year-2000)*12+recjob.reporting_month as mid,
recjob.scheduled_date, recmtd.run_date,
    recjob.job_id, recjob.contact_method,
    rec.orig_contact_method, rec.orig_metric_type,
    trim (recmtd.npanxxx) || recmtd.last_three_digit as mdn,
recmtd.config_id as cid, recmtd.activity_code as act
  from obc_master.lu_obc_rcontact_job_addnl_info
rec,obc_master.lu_obc_job_info recjob ,obc_master.fa_obc_mdn_mtd recmtd
,obc_load.npa_nxx_outbound l
where  recjob.job_id = rec.job_id
  and recmtd.job_id = rec.job_id
  and l.npanxxx = recmtd.npanxxx
  and recjob.contact_type = 'r'
  and rec.orig_contact_type = 'p'
);

The query select * from obc_master.recontacts where ocid = 9 and mid = 48 and act in (1,2) never finishes as before.

Here is the Plan

Explanation
--------------------------------------------------
 
  1)First, we lock obc_master.lu_obc_rcontact_job_addnl_info for access, we lock obc_master.fa_obc_mdn_mtd for access, we lock obc_master.lu_obc_job_info for access, and we lock obc_load.npa_nxx_outbound for access.  
  2)Next, we execute the following steps in parallel.  
   
  1) We do an all-AMPs JOIN step from obc_master.rec by way of a RowHash match scan. with a condition of ("obc_master.rec.ORIG_CONTACT_TYPE = 'p'"), which is joined to obc_master.recjob with a condition of ("((((obc_master.recjob.REPORTING_YEAR - 2000 )* 12 )+ obc_master.recjob.REPORTING_MONTH )= 48) AND (obc_master.recjob.CONTACT_TYPE = 'r')"). obc_master.rec and obc_master.recjob are joined using a merge join, with a join condition of ("obc_master.recjob.JOB_ID = obc_master.rec.JOB_ID"). The result goes into Spool 2, which is duplicated on all AMPs. The size of Spool 2 is estimated with no confidence to be 2,656 rows. The estimated time for this step is 0.28 seconds.
 
   
  2) We do an all-AMPs RETRIEVE step from obc_load.l by way of an all-rows scan with a condition of ("(obc_load.l.OWNER_CARRIER_ID = 9) AND (NOT (obc_load.l.NPANXXX IS NULL ))") into Spool 3, which is redistributed by hash code to all AMPs. Then we do a SORT to order Spool 3 by row hash. The size of Spool 3 is estimated with no confidence to be 11,521 rows. The estimated time for this step is 0.43 seconds.
 
  3)We do an all-AMPs JOIN step from Spool 2 (Last Use) by way of an all-rows scan, which is joined to obc_master.recmtd with a condition of ("(obc_master.recmtd.ACTIVITY_CODE = 1) OR (obc_master.recmtd.ACTIVITY_CODE = 2)"). Spool 2 and obc_master.recmtd are joined using a product join, with a join condition of ("(obc_master.recmtd.JOB_ID = JOB_ID) AND (JOB_ID = obc_master.recmtd.JOB_ID)"). The input table obc_master.recmtd will not be cached in memory. The result goes into Spool 4, which is redistributed by hash code to all AMPs. Then we do a SORT to order Spool 4 by row hash. The size of Spool 4 is estimated with no confidence to be 28,913 rows. The estimated time for this step is 1 minute and 38 seconds.  
  4)We do an all-AMPs JOIN step from Spool 3 (Last Use) by way of a RowHash match scan., which is joined to Spool 4 (Last Use). Spool 3 and Spool 4 are joined using a merge join, with a join condition of ("NPANXXX = NPANXXX"). The result goes into Spool 1, which is built locally on the AMPs. The size of Spool 1 is estimated with no confidence to be 347,329 to 333,106,673 rows. The estimated time for this step is 2.99 seconds to 44 minutes and 23 seconds.  
  5)Finally, we send out an END TRANSACTION step to all AMPs involved in processing the request.  
  ->The contents of Spool 1 are sent back to the user as the result of statement 1. The total estimated time is 1 minute and 42 seconds.  


I joined the view with Temp table and executed the query

select * from  OBC_MASTER.LU_temp  A, obc_master.recontacts B
where A.act = B.act
and ocid = 9 and mid = 48

It brought the results in 10 seconds

Explanation
--------------------------------------------------
 
  1)First, we lock a distinct OBC_MASTER."pseudo table" for read on a RowHash to prevent global deadlock for OBC_MASTER.A.  
  2)Next, we lock OBC_MASTER.A for read, we lock obc_master.lu_obc_rcontact_job_addnl_info for access, we lock obc_master.fa_obc_mdn_mtd for access, we lock obc_master.lu_obc_job_info for access, and we lock obc_load.npa_nxx_outbound for access.  
  3)We do an all-AMPs RETRIEVE step from obc_master.rec by way of an all-rows scan with a condition of ("obc_master.rec.ORIG_CONTACT_TYPE = 'p'") into Spool 2, which is duplicated on all AMPs. Then we do a SORT to order Spool 2 by row hash. The size of Spool 2 is estimated with no confidence to be 6,048 rows. The estimated time for this step is 0.04 seconds.  
  4)We execute the following steps in parallel.  
   
  1) We do an all-AMPs JOIN step from Spool 2 (Last Use) by way of an all-rows scan, which is joined to obc_master.recmtd by way of a traversal of index # 4 extracting row ids only. Spool 2 and obc_master.recmtd are joined using a nested join, with a join condition of ("obc_master.recmtd.JOB_ID = JOB_ID"). The input table obc_master.recmtd will not be cached in memory. The result goes into Spool 3, which is built locally on the AMPs. Then we do a SORT to order Spool 3 by field Id 1. The size of Spool 3 is estimated with no confidence to be 346,516 rows. The estimated time for this step is 1 minute and 54 seconds.
 
   
  2) We do an all-AMPs RETRIEVE step from obc_master.recjob by way of an all-rows scan with a condition of ("((((obc_master.recjob.REPORTING_YEAR - 2000 )* 12 )+ obc_master.recjob.REPORTING_MONTH )= 48) AND (obc_master.recjob.CONTACT_TYPE = 'r')") into Spool 4, which is redistributed by hash code to all AMPs. Then we do a SORT to order Spool 4 by row hash. The size of Spool 4 is estimated with low confidence to be 3,288 rows. The estimated time for this step is 0.17 seconds.
 
  5)We do an all-AMPs JOIN step from Spool 3 (Last Use) by way of an all-rows scan, which is joined to obc_master.recmtd. Spool 3 and obc_master.recmtd are joined using a row id join, with a join condition of ("(1=1)"). The input table obc_master.recmtd will not be cached in memory. The result goes into Spool 5, which is redistributed by hash code to all AMPs. Then we do a SORT to order Spool 5 by row hash. The size of Spool 5 is estimated with no confidence to be 346,516 rows. The estimated time for this step is 1 minute and 59 seconds.  
  6)We do an all-AMPs JOIN step from Spool 4 (Last Use) by way of a RowHash match scan., which is joined to Spool 5 (Last Use). Spool 4 and Spool 5 are joined using a merge join, with a join condition of ("(JOB_ID = JOB_ID) AND (JOB_ID = JOB_ID)"). The result goes into Spool 6, which is redistributed by hash code to all AMPs. Then we do a SORT to order Spool 6 by row hash. The size of Spool 6 is estimated with no confidence to be 3,288 rows. The estimated time for this step is 1.12 seconds.  
  7)We execute the following steps in parallel.  
   
  1) We do an all-AMPs JOIN step from OBC_MASTER.A by way of a RowHash match scan. with no residual conditions, which is joined to Spool 6 (Last Use). OBC_MASTER.A and Spool 6 are joined using a merge join, with a join condition of ("OBC_MASTER.A.act = ACTIVITY_CODE"). The result goes into Spool 7, which is redistributed by hash code to all AMPs. Then we do a SORT to order Spool 7 by row hash. The size of Spool 7 is estimated with no confidence to be 3,288 rows. The estimated time for this step is 0.12 seconds.
 
   
  2) We do an all-AMPs RETRIEVE step from obc_load.l by way of an all-rows scan with a condition of ("(obc_load.l.OWNER_CARRIER_ID = 9) AND (NOT (obc_load.l.NPANXXX IS NULL ))") into Spool 8, which is redistributed by hash code to all AMPs. Then we do a SORT to order Spool 8 by row hash. The size of Spool 8 is estimated with no confidence to be 11,521 rows. The estimated time for this step is 0.43 seconds.
 
  8)We do an all-AMPs JOIN step from Spool 7 (Last Use) by way of a RowHash match scan., which is joined to Spool 8 (Last Use). Spool 7 and Spool 8 are joined using a merge join, with a join condition of ("NPANXXX = NPANXXX"). The result goes into Spool 1, which is built locally on the AMPs. The size of Spool 1 is estimated with no confidence to be 62,624 to 37,881,048 rows. The estimated time for this step is 0.71 seconds to 5 minutes and 11 seconds.  
  9)Finally, we send out an END TRANSACTION step to all AMPs involved in processing the request.  
  ->The contents of Spool 1 are sent back to the user as the result of statement 1. The total estimated time is 3 minutes and 55 seconds.  



     
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