Table R (A)
containing the records [(3), (4), (5)]
and transactions T1
= UPDATE R SET A = A * 2; INSERT INTO A VALUES (6);
and T2 = 'SELECT AVG (A) FROM R; SELECT AVG (A) FROM R'
Knowing that transaction T2
is executed using repeatable-read which are the posible values returned by the second select?
I think that possible values are: 4
and 7.5
? Am I right? Please let me know if I correctly understand repeatable-read.