Serializability Examples (cont’d)
Client must control the relative order of transactions, using handshakes (wait for T1to commit before submitting T2).
Some more serializable executions:r1[x] r2[y] w2[y] w1[x] ? T1 T2 ? T2 T1r1[y] r2[y] w2[y] w1[x] ? T1 T2 ? T2 T1r1[x] r2[y] w2[y] w1[y] ? T2 T1 ? T1 T2
Serializability says the execution is equivalent to some serial order, not necessarily to all serial orders