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Message Posted: Fri, 25 Nov 2011 @ 09:07:57 GMT

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Subj:   Re: Performance issue after splitting the big table
From:   Jinesh P V

Hi, One possible solutions is:

if you had created 6 parts from the original table based on values of a specific column, for example department, you can use that in the view as below.

     replace view v_large_table as
     select 1 as department, a.* from large_table_department1 a union all select 2 as
     department, a.* from large_table_department2 a union all select 3 as department, a.* from
     large_table_department3 a union all .....
     select 6 as department, a.* from large_table_department6 a ;

And then, if you use the column department in all queries, Teradata will scan only the specific table based on the satisfiability. (Otherwise it will have scan all 6 tables and do the 'union all' as it may be happening now.)

     explain select * from  v_large_table
     where department = 2



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