@@ -31,6 +31,7 @@ var cfg struct {
3131ConnStrs ConnStrings
3232
3333Verbose bool
34+ UseDtm bool
3435Isolation string // "repeatable read" or "read committed"
3536
3637Accounts struct {
@@ -102,6 +103,7 @@ func init() {
102103flag .IntVar (& cfg .Writers .Num ,"w" ,8 ,"The number of writers" )
103104flag .IntVar (& cfg .Writers .Updates ,"u" ,10000 ,"The number updates each writer performs" )
104105flag .BoolVar (& cfg .Verbose ,"v" ,false ,"Show progress and other stuff for mortals" )
106+ flag .BoolVar (& cfg .UseDtm ,"m" ,false ,"Use DTM to keep global consistency" )
105107flag .BoolVar (& cfg .Writers .AllowGlobal ,"g" ,false ,"Allow global updates" )
106108flag .BoolVar (& cfg .Writers .AllowLocal ,"l" ,false ,"Allow local updates" )
107109flag .BoolVar (& cfg .Writers .PrivateRows ,"p" ,false ,"Private rows (avoid waits/aborts caused by concurrent updates of the same rows)" )
@@ -199,8 +201,10 @@ func prepare_one(connstr string, wg *sync.WaitGroup) {
199201
200202defer conn .Close ()
201203
202- exec (conn ,"drop extension if exists pg_dtm" )
203- exec (conn ,"create extension pg_dtm" )
204+ if cfg .UseDtm {
205+ exec (conn ,"drop extension if exists pg_dtm" )
206+ exec (conn ,"create extension pg_dtm" )
207+ }
204208exec (conn ,"drop table if exists t" )
205209exec (conn ,"create table t(u int primary key, v int)" )
206210
@@ -318,7 +322,9 @@ func writer(id int, cCommits chan int, cAborts chan int, wg *sync.WaitGroup) {
318322 }
319323
320324// global single-node update
321- execQuery (src ,"select dtm_begin_transaction()" )
325+ if cfg .UseDtm {
326+ execQuery (src ,"select dtm_begin_transaction()" )
327+ }
322328
323329// start transaction
324330exec (src ,"begin transaction isolation level " + cfg .Isolation )
@@ -368,8 +374,10 @@ func writer(id int, cCommits chan int, cAborts chan int, wg *sync.WaitGroup) {
368374continue
369375 }
370376
371- xid := execQuery (src ,"select dtm_begin_transaction()" )
372- exec (dst ,"select dtm_join_transaction($1)" ,xid )
377+ if cfg .UseDtm {
378+ xid := execQuery (src ,"select dtm_begin_transaction()" )
379+ exec (dst ,"select dtm_join_transaction($1)" ,xid )
380+ }
373381
374382// start transaction
375383exec (src ,"begin transaction isolation level " + cfg .Isolation )
@@ -454,10 +462,12 @@ func reader(wg *sync.WaitGroup, inconsistency *bool) {
454462var sum int64 = 0
455463var xid int32
456464for i ,conn := range conns {
457- if i == 0 {
458- xid = execQuery (conn ,"select dtm_begin_transaction()" )
459- }else {
460- exec (conn ,"select dtm_join_transaction($1)" ,xid )
465+ if cfg .UseDtm {
466+ if i == 0 {
467+ xid = execQuery (conn ,"select dtm_begin_transaction()" )
468+ }else {
469+ exec (conn ,"select dtm_join_transaction($1)" ,xid )
470+ }
461471 }
462472
463473exec (conn ,"begin transaction isolation level " + cfg .Isolation )