@@ -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
@@ -317,7 +321,9 @@ func writer(id int, cCommits chan int, cAborts chan int, wg *sync.WaitGroup) {
317321 }
318322
319323// global single-node update
320- execQuery (src ,"select dtm_begin_transaction()" )
324+ if cfg .UseDtm {
325+ execQuery (src ,"select dtm_begin_transaction()" )
326+ }
321327
322328// start transaction
323329exec (src ,"begin transaction isolation level " + cfg .Isolation )
@@ -367,8 +373,10 @@ func writer(id int, cCommits chan int, cAborts chan int, wg *sync.WaitGroup) {
367373continue
368374 }
369375
370- xid := execQuery (src ,"select dtm_begin_transaction()" )
371- exec (dst ,"select dtm_join_transaction($1)" ,xid )
376+ if cfg .UseDtm {
377+ xid := execQuery (src ,"select dtm_begin_transaction()" )
378+ exec (dst ,"select dtm_join_transaction($1)" ,xid )
379+ }
372380
373381// start transaction
374382exec (src ,"begin transaction isolation level " + cfg .Isolation )
@@ -453,10 +461,12 @@ func reader(wg *sync.WaitGroup, inconsistency *bool) {
453461var sum int64 = 0
454462var xid int32
455463for i ,conn := range conns {
456- if i == 0 {
457- xid = execQuery (conn ,"select dtm_begin_transaction()" )
458- }else {
459- exec (conn ,"select dtm_join_transaction($1)" ,xid )
464+ if cfg .UseDtm {
465+ if i == 0 {
466+ xid = execQuery (conn ,"select dtm_begin_transaction()" )
467+ }else {
468+ exec (conn ,"select dtm_join_transaction($1)" ,xid )
469+ }
460470 }
461471
462472exec (conn ,"begin transaction isolation level " + cfg .Isolation )