•SET TRANACTION
ISOLATION LEVEL REPEATABLE
READ
–Set read
locks on data items, and hold them till txn finished, but release locks on indices as soon as index has been examined
–Allows
“phantoms”, rows that are not seen in a query that ought to have been (or vice versa)
–Problems if one txn is changing the set of rows that meet a condition, while another txn is retrieving that
set