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Message Posted: Mon, 24 Sep 2001 @ 18:25:44 GMT


     
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Subj:   Re: Updating one table with values from another
 
From:   Karen Gebhard

They look exactly the same:

Explanation
--------------------------------------------------
 
  1)First, we lock a distinct offline_staging_incr_dev."pseudo table" for read on a RowHash to prevent global deadlock for offline_staging_incr_dev.sale_offline_conv.  
  2)Next, we lock a distinct eti."pseudo table" for write on a RowHash to prevent global deadlock for eti.sales_org_hier.  
  3)We lock offline_staging_incr_dev.sale_offline_conv for read, and we lock eti.sales_org_hier for write.  
  4)We do a MERGE DELETE to eti.sales_org_hier from offline_staging_incr_dev.sale_offline_conv. New updated rows are built and the result goes into Spool 1, which is built locally on the AMPs. Then we do a SORT to order Spool 1 by row hash. New updated rows are built and the result goes into Spool 1, which is built locally on the AMPs. Then we do a SORT to order Spool 1 by row hash.  
  5)We do a MERGE into eti.sales_org_hier from Spool 1 (Last Use).  
  6)Finally, we send out an END TRANSACTION step to all AMPs involved in processing the request.  
  ->No rows are returned to the user as the result of statement 1.  



     
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