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Former Member

use_hash in derived table

Is it possible to use use_hash in the derived table?

I get a warning "Each calculated column must have an explicit name" if I include

select /*+ use_hash(table_names) */.It parses ok if I remove this line.Basically query runs for a long time without use_hash.

Can somebody help me with this?

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1 Answer

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    Former Member
    May 27, 2011 at 12:28 PM

    As it says, each column must have a unique name.

    This is so that you can select it when building objects and predefined conditions.

    Please can you post the SQL that you want to use?

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    • Former Member Former Member

      I use oracle database.

      When I run the report without the use_hash it is taking more than 3 hours and when hash is applied it returns within 25 seconds.

      When I run the query against the database I observed the similar performance.