>>>> This field come from a COALESCE(FIELD1,FIELD2) and both fields have a
>>>> FK.
>>>> Gabor

do you mean that instead id_parent column you have COALESCE(FIELD1,FIELD2)?
IF yes, then only expression index can help here if Field1 and 2 is from
same table.
Without this index i suppose you got NATURAL PLAN...

regards,
Karol Bieniaszewski


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