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Archives of the TeradataForum
Message Posted: Wed, 21 Jan 2004 @ 17:27:09 GMT
Subj: | | Re: Statistics and explain plans |
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From: | | Claybourne Barrineau |
Anomy,
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,
Clay
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