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Message Posted: Wed, 21 Jan 2004 @ 17:27:09 GMT

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Subj:   Re: Statistics and explain plans
From:   Claybourne Barrineau


It appears that dss_tables.po_header_tbl has no statistics on the collective set of join columns (h.branch_id, h.sequence_no, h.date_transaction.) Maybe individual stats exists on the seperate columns, but this wouldn't help the optimizer too much. The optimizer needs stats on all three columns (this can be done in V2R5, in V2R4, you will need to create a NUSI on these columns.) This might be helpful for all join columns.

Also, the left outer join to the derived table will result in no confidence (because the optimizer will have no stats on result of the derived table).

Hope this helps,


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