using of index

[alainc]

hi all,

i had a delete statement like this in a trigger

delete from histo where num <(b1 -30000)
b1 is a parameter coming from a sequence

there's an index on num and only on that colum which is the primary key

when i look at the plan he always do a full table scan to delete

why ? is it coming from the parameters

[tekion]

I am not sure, but here's what I learned from reading this forum.
Bec. the FK is not index, when you do a delete from the
parent table, oracle does a full tables scan on the child table for
data integrity purposes. You can truncate your child table or have FK on your child table index.

[Edited by tekion on 02-06-2002 at 02:02 PM]