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2006-06-22 10:01:20 PM
delphi103
what is better to do :
Select *
From
PROPERTY
JOIN TRANSAC ON PROPERTY.ID=TRANSAC.ID_PROPERTY
JOIN PROPERTY_PUBLICATION ON PROPERTY.ID=PROPERTY_PUBLICATION.ID_PROPERTY
or
Select *
From
TRANSAC
JOIN PROPERTY ON PROPERTY.ID=TRANSAC.ID_PROPERTY
JOIN PROPERTY_PUBLICATION ON PROPERTY.ID=PROPERTY_PUBLICATION.ID_PROPERTY
??
at the same what will be the best plan to use ?
Thanks by advance
stéphane
 

loki writes:
and the selectivity of those indexes. Without knowing that there is now way
to guess which is going to be faster except by trying them yourself.
I tend to write my queries like your first query - with an eye to flattening
the relationships - i.e. the two joined tables are at the same level, both
linking to the main table. However, if I am suspicious of the plan it gives
me or the actual performance then I will certainly try alternatives such as
your 2nd example.
If, for the 2nd example, the join on PROPERTY_PUBLICATION will greatly
restrict the resulting rows from PROPERTY, then that may make the subsequent
join to TRANSAC more efficient.
--
Wayne Niddery - Winwright, Inc (www.winwright.ca)
"True peace is not the absence of tension, but the presence of
justice." - Martin Luther King, Jr.
 

Ivan