poor query performance

I have a query that deletes rows from a table with 57K rows, as follows

delete from T1 where not exists
(select T2.PK from T2

where T2.PK = T1.F1);

T2.PK is the Primary Key on Table T2
T1.F1 is an indexed field on table T1

Explain plan shows a low cost (80) but the delete takes about 10+ minutes. T1 has about 57K rows
T2 has about 29500 rows

other queries with costs in the 700 range are pretty quick - this one's a dog

any ideas?

thanks

Bill Magaliff
Framework, Inc.
914-631-2322

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