 Union in Views: No Branch Elimination because predicate with NonCor-Subselect ?
Hello
I've experienced that DB2 unfortunately does not eliminate subselects
of a UnionAll-View if the predicate's content is not hardcoded but
derived from a base-table with a noncorrelated Subselect.
Any plans to enhance this for the future? Any workaround suggestions?
Thanks in advance
Susanne
Sample:
* T1 contains all records for branch X, T2 for branch Y, and T3 for branch Z
* Create View ALLRECS as
select * from T1 where branch = 'X'
union all
select * from T2 where branch = 'Y'...
* NO Check Constraints
* SELECT...
FROM ALLRECS
WHERE branch in (Select branch
from BASETAB
where owner = 'SUE')
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