@@ -15,6 +15,8 @@ const (
1515N_ACCOUNTS = TRANSFER_CONNECTIONS //100000
1616//ISOLATION_LEVEL = "repeatable read"
1717ISOLATION_LEVEL = "read committed"
18+ GLOBAL_UPDATES = true
19+ LOCAL_UPDATES = false
1820)
1921
2022
@@ -132,11 +134,20 @@ func transfer(id int, cCommits chan int, cAborts chan int, wg *sync.WaitGroup) {
132134account1 := rand .Intn (N_ACCOUNTS )
133135account2 := rand .Intn (N_ACCOUNTS )
134136
137+ if (account1 >= account2 ) {
138+ continue
139+ }
140+
135141src := conn [rand .Intn (2 )]
136142dst := conn [rand .Intn (2 )]
137143
138144if src == dst {
139- // local transaction
145+ // local update
146+ if ! LOCAL_UPDATES {
147+ // which we do not want
148+ continue
149+ }
150+
140151exec (src ,"begin transaction isolation level " + ISOLATION_LEVEL )
141152ok1 := execUpdate (src ,"update t set v = v - $1 where u=$2" ,amount ,account1 )
142153ok2 := execUpdate (src ,"update t set v = v + $1 where u=$2" ,amount ,account2 )
@@ -149,7 +160,12 @@ func transfer(id int, cCommits chan int, cAborts chan int, wg *sync.WaitGroup) {
149160myCommits += 1
150161 }
151162 }else {
152- // global transaction
163+ // global update
164+ if ! GLOBAL_UPDATES {
165+ // which we do not want
166+ continue
167+ }
168+
153169xid = execQuery (src ,"select dtm_begin_transaction(2)" )
154170exec (dst ,"select dtm_join_transaction($1)" ,xid )
155171
@@ -263,6 +279,9 @@ func execUpdate(conn *pgx.Conn, stmt string, arguments ...interface{}) bool {
263279var err error
264280// fmt.Println(stmt)
265281_ ,err = conn .Exec (stmt ,arguments ... )
282+ if err != nil {
283+ fmt .Println (err )
284+ }
266285return err == nil
267286}
268287