Improve display of query results in isolation tests.

Previously, isolationtester displayed SQL query results using some
ad-hoc code that clearly hadn't had much effort expended on it.
Field values longer than 14 characters weren't separated from
the next field, and usually caused misalignment of the columns
too.  Also there was no visual separation of a query's result
from subsequent isolationtester output.  This made test result
files confusing and hard to read.

To improve matters, let's use libpq's PQprint() function.  Although
that's long since unused by psql, it's still plenty good enough
for the purpose here.

Like 741d7f10, back-patch to all supported branches, so that this
isn't a stumbling block for back-patching isolation test changes.

Discussion: https://postgr.es/m/582362.1623798221@sss.pgh.pa.us

contrib/test_decoding/expected/concurrent_stream.out

@@ -10,11 +10,15 @@ step s2_ddl: CREATE TABLE stream_test2(data text);
 step s1_commit: COMMIT;
 step s1_get_stream_changes: SELECT data FROM pg_logical_slot_get_changes('isolation_slot', NULL,NULL, 'include-xids', '0', 'skip-empty-xacts', '1', 'stream-changes', '1');
 data                                    
-
+----------------------------------------
 opening a streamed block for transaction
 streaming change for transaction        
 closing a streamed block for transaction
 committing streamed transaction         
-?column?       
+(4 rows)
 
+?column?
+--------
 stop    
+(1 row)
+

contrib/test_decoding/expected/delayed_startup.out

@@ -7,32 +7,44 @@ step s2init: SELECT 'init' FROM pg_create_logical_replication_slot('isolation_sl
 step s1c: COMMIT;
 step s2init: <... completed>
 ?column?
-
+--------
 init    
+(1 row)
+
 step s2start: SELECT data FROM pg_logical_slot_get_changes('isolation_slot', NULL, NULL, 'include-xids', 'false');
 data
+----
+(0 rows)
 
 step s1b: BEGIN ISOLATION LEVEL SERIALIZABLE;
 step s1w: INSERT INTO do_write DEFAULT VALUES;
 step s1c: COMMIT;
 step s2start: SELECT data FROM pg_logical_slot_get_changes('isolation_slot', NULL, NULL, 'include-xids', 'false');
 data                                        
-
+--------------------------------------------
 BEGIN                                       
 table public.do_write: INSERT: id[integer]:2
 COMMIT                                      
+(3 rows)
+
 step s1b: BEGIN ISOLATION LEVEL SERIALIZABLE;
 step s1w: INSERT INTO do_write DEFAULT VALUES;
 step s2start: SELECT data FROM pg_logical_slot_get_changes('isolation_slot', NULL, NULL, 'include-xids', 'false');
 data
+----
+(0 rows)
 
 step s1c: COMMIT;
 step s2start: SELECT data FROM pg_logical_slot_get_changes('isolation_slot', NULL, NULL, 'include-xids', 'false');
 data                                        
-
+--------------------------------------------
 BEGIN                                       
 table public.do_write: INSERT: id[integer]:3
 COMMIT                                      
-?column?       
+(3 rows)
 
+?column?
+--------
 stop    
+(1 row)
+

contrib/test_decoding/expected/mxact.out

@@ -3,64 +3,88 @@ Parsed test spec with 3 sessions
 starting permutation: s0init s0start s1begin s1sharepgclass s2begin s2sharepgclass s0w s0start s2commit s1commit
 step s0init: SELECT 'init' FROM pg_create_logical_replication_slot('isolation_slot', 'test_decoding');
 ?column?
-
+--------
 init    
+(1 row)
+
 step s0start: SELECT data FROM pg_logical_slot_get_changes('isolation_slot', NULL, NULL, 'include-xids', 'false');
 data
+----
+(0 rows)
 
 step s1begin: BEGIN;
 step s1sharepgclass: SELECT count(*) > 1 FROM (SELECT * FROM pg_class FOR SHARE) s;
 ?column?
-
+--------
 t       
+(1 row)
+
 step s2begin: BEGIN;
 step s2sharepgclass: SELECT count(*) > 1 FROM (SELECT * FROM pg_class FOR SHARE) s;
 ?column?
-
+--------
 t       
+(1 row)
+
 step s0w: INSERT INTO do_write DEFAULT VALUES;
 step s0start: SELECT data FROM pg_logical_slot_get_changes('isolation_slot', NULL, NULL, 'include-xids', 'false');
 data                                        
-
+--------------------------------------------
 BEGIN                                       
 table public.do_write: INSERT: id[integer]:1
 COMMIT                                      
+(3 rows)
+
 step s2commit: COMMIT;
 step s1commit: COMMIT;
 ?column?
-
+--------
 stop    
+(1 row)
+
 
 starting permutation: s0init s0start s1begin s1keysharepgclass s2begin s2keysharepgclass s0alter s0w s0start s2commit s1commit
 step s0init: SELECT 'init' FROM pg_create_logical_replication_slot('isolation_slot', 'test_decoding');
 ?column?
-
+--------
 init    
+(1 row)
+
 step s0start: SELECT data FROM pg_logical_slot_get_changes('isolation_slot', NULL, NULL, 'include-xids', 'false');
 data
+----
+(0 rows)
 
 step s1begin: BEGIN;
 step s1keysharepgclass: SELECT count(*) > 1 FROM (SELECT * FROM pg_class FOR KEY SHARE) s;
 ?column?
-
+--------
 t       
+(1 row)
+
 step s2begin: BEGIN;
 step s2keysharepgclass: SELECT count(*) > 1 FROM (SELECT * FROM pg_class FOR KEY SHARE) s;
 ?column?
-
+--------
 t       
+(1 row)
+
 step s0alter: ALTER TABLE do_write ADD column ts timestamptz;
 step s0w: INSERT INTO do_write DEFAULT VALUES;
 step s0start: SELECT data FROM pg_logical_slot_get_changes('isolation_slot', NULL, NULL, 'include-xids', 'false');
 data                                                                          
-
+------------------------------------------------------------------------------
 BEGIN                                                                         
 COMMIT                                                                        
 BEGIN                                                                         
 table public.do_write: INSERT: id[integer]:1 ts[timestamp with time zone]:null
 COMMIT                                                                        
+(5 rows)
+
 step s2commit: COMMIT;
 step s1commit: COMMIT;
 ?column?
-
+--------
 stop    
+(1 row)
+

contrib/test_decoding/expected/oldest_xmin.out

@@ -4,8 +4,10 @@ starting permutation: s0_begin s0_getxid s1_begin s1_insert s0_alter s0_commit s
 step s0_begin: BEGIN;
 step s0_getxid: SELECT pg_current_xact_id() IS NULL;
 ?column?
-
+--------
 f       
+(1 row)
+
 step s1_begin: BEGIN;
 step s1_insert: INSERT INTO harvest VALUES ((1, 2, 3));
 step s0_alter: ALTER TYPE basket DROP ATTRIBUTE mangos;
@@ -13,18 +15,26 @@ step s0_commit: COMMIT;
 step s0_checkpoint: CHECKPOINT;
 step s0_get_changes: SELECT data FROM pg_logical_slot_get_changes('isolation_slot', NULL, NULL, 'include-xids', '0', 'skip-empty-xacts', '1');
 data
+----
+(0 rows)
 
 step s0_get_changes: SELECT data FROM pg_logical_slot_get_changes('isolation_slot', NULL, NULL, 'include-xids', '0', 'skip-empty-xacts', '1');
 data
+----
+(0 rows)
 
 step s1_commit: COMMIT;
 step s0_vacuum: VACUUM pg_attribute;
 step s0_get_changes: SELECT data FROM pg_logical_slot_get_changes('isolation_slot', NULL, NULL, 'include-xids', '0', 'skip-empty-xacts', '1');
 data                                                  
-
+------------------------------------------------------
 BEGIN                                                 
 table public.harvest: INSERT: fruits[basket]:'(1,2,3)'
 COMMIT                                                
-?column?       
+(3 rows)
 
+?column?
+--------
 stop    
+(1 row)
+

contrib/test_decoding/expected/ondisk_startup.out

@@ -4,41 +4,51 @@ starting permutation: s2b s2txid s1init s3b s3txid s2alter s2c s2b s2txid s3c s2
 step s2b: BEGIN;
 step s2txid: SELECT pg_current_xact_id() IS NULL;
 ?column?
-
+--------
 f       
+(1 row)
+
 step s1init: SELECT 'init' FROM pg_create_logical_replication_slot('isolation_slot', 'test_decoding'); <waiting ...>
 step s3b: BEGIN;
 step s3txid: SELECT pg_current_xact_id() IS NULL;
 ?column?
-
+--------
 f       
+(1 row)
+
 step s2alter: ALTER TABLE do_write ADD COLUMN addedbys2 int;
 step s2c: COMMIT;
 step s2b: BEGIN;
 step s2txid: SELECT pg_current_xact_id() IS NULL;
 ?column?
-
+--------
 f       
+(1 row)
+
 step s3c: COMMIT;
 step s1init: <... completed>
 ?column?
-
+--------
 init    
+(1 row)
+
 step s2c: COMMIT;
 step s1insert: INSERT INTO do_write DEFAULT VALUES;
 step s1checkpoint: CHECKPOINT;
 step s1start: SELECT data FROM pg_logical_slot_get_changes('isolation_slot', NULL, NULL, 'include-xids', 'false');
 data                                                                
-
+--------------------------------------------------------------------
 BEGIN                                                               
 table public.do_write: INSERT: id[integer]:1 addedbys2[integer]:null
 COMMIT                                                              
+(3 rows)
+
 step s1insert: INSERT INTO do_write DEFAULT VALUES;
 step s1alter: ALTER TABLE do_write ADD COLUMN addedbys1 int;
 step s1insert: INSERT INTO do_write DEFAULT VALUES;
 step s1start: SELECT data FROM pg_logical_slot_get_changes('isolation_slot', NULL, NULL, 'include-xids', 'false');
 data                                                                                        
-
+--------------------------------------------------------------------------------------------
 BEGIN                                                                                       
 table public.do_write: INSERT: id[integer]:2 addedbys2[integer]:null                        
 COMMIT                                                                                      
@@ -47,6 +57,10 @@ COMMIT
 BEGIN                                                                                       
 table public.do_write: INSERT: id[integer]:3 addedbys2[integer]:null addedbys1[integer]:null
 COMMIT                                                                                      
-?column?       
+(8 rows)
 
+?column?
+--------
 stop    
+(1 row)
+

contrib/test_decoding/expected/snapshot_transfer.out

@@ -5,8 +5,10 @@ step s0_begin: BEGIN;
 step s0_begin_sub0: SAVEPOINT s0;
 step s0_log_assignment: SELECT pg_current_xact_id() IS NULL;
 ?column?
-
+--------
 f       
+(1 row)
+
 step s0_sub_get_base_snap: INSERT INTO dummy VALUES (0);
 step s1_produce_new_snap: ALTER TABLE harvest ADD COLUMN mangos int;
 step s0_insert: INSERT INTO harvest VALUES (1, 2, 3);
@@ -14,22 +16,28 @@ step s0_end_sub0: RELEASE SAVEPOINT s0;
 step s0_commit: COMMIT;
 step s0_get_changes: SELECT data FROM pg_logical_slot_get_changes('isolation_slot', NULL, NULL, 'include-xids', '0', 'skip-empty-xacts', '1');
 data                                                                              
-
+----------------------------------------------------------------------------------
 BEGIN                                                                             
 table public.dummy: INSERT: i[integer]:0                                          
 table public.harvest: INSERT: apples[integer]:1 pears[integer]:2 mangos[integer]:3
 COMMIT                                                                            
-?column?       
+(4 rows)
 
+?column?
+--------
 stop    
+(1 row)
+
 
 starting permutation: s0_begin s0_begin_sub0 s0_log_assignment s0_begin_sub1 s0_sub_get_base_snap s1_produce_new_snap s0_insert s0_end_sub1 s0_end_sub0 s0_commit s0_get_changes
 step s0_begin: BEGIN;
 step s0_begin_sub0: SAVEPOINT s0;
 step s0_log_assignment: SELECT pg_current_xact_id() IS NULL;
 ?column?
-
+--------
 f       
+(1 row)
+
 step s0_begin_sub1: SAVEPOINT s1;
 step s0_sub_get_base_snap: INSERT INTO dummy VALUES (0);
 step s1_produce_new_snap: ALTER TABLE harvest ADD COLUMN mangos int;
@@ -39,11 +47,15 @@ step s0_end_sub0: RELEASE SAVEPOINT s0;
 step s0_commit: COMMIT;
 step s0_get_changes: SELECT data FROM pg_logical_slot_get_changes('isolation_slot', NULL, NULL, 'include-xids', '0', 'skip-empty-xacts', '1');
 data                                                                              
-
+----------------------------------------------------------------------------------
 BEGIN                                                                             
 table public.dummy: INSERT: i[integer]:0                                          
 table public.harvest: INSERT: apples[integer]:1 pears[integer]:2 mangos[integer]:3
 COMMIT                                                                            
-?column?       
+(4 rows)
 
+?column?
+--------
 stop    
+(1 row)
+

contrib/test_decoding/expected/subxact_without_top.out

@@ -16,24 +16,34 @@ step s1_begin: BEGIN;
 step s1_dml: INSERT INTO harvest VALUES (43);
 step s0_many_subxacts: select subxacts();
 subxacts
+--------
         
+(1 row)
 
 step s0_commit: COMMIT;
 step s2_checkpoint: CHECKPOINT;
 step s2_get_changes_suppress_output: SELECT null n FROM pg_logical_slot_get_changes('isolation_slot', NULL, NULL, 'include-xids', '0', 'skip-empty-xacts', '1') GROUP BY n;
 n
+-
  
+(1 row)
 
 step s2_get_changes_suppress_output: SELECT null n FROM pg_logical_slot_get_changes('isolation_slot', NULL, NULL, 'include-xids', '0', 'skip-empty-xacts', '1') GROUP BY n;
 n
+-
+(0 rows)
 
 step s1_commit: COMMIT;
 step s2_get_changes: SELECT data FROM pg_logical_slot_get_changes('isolation_slot', NULL, NULL, 'include-xids', '0', 'skip-empty-xacts', '1');
 data                                            
-
+------------------------------------------------
 BEGIN                                           
 table public.harvest: INSERT: apples[integer]:43
 COMMIT                                          
-?column?       
+(3 rows)
 
+?column?
+--------
 stop    
+(1 row)
+

contrib/test_decoding/expected/twophase_snapshot.out

@@ -4,14 +4,18 @@ starting permutation: s2b s2txid s1init s3b s3txid s2c s2b s2insert s2p s3c s1in
 step s2b: BEGIN;
 step s2txid: SELECT pg_current_xact_id() IS NULL;
 ?column?
-
+--------
 f       
+(1 row)
+
 step s1init: SELECT 'init' FROM pg_create_logical_replication_slot('isolation_slot', 'test_decoding', false, true); <waiting ...>
 step s3b: BEGIN;
 step s3txid: SELECT pg_current_xact_id() IS NULL;
 ?column?
-
+--------
 f       
+(1 row)
+
 step s2c: COMMIT;
 step s2b: BEGIN;
 step s2insert: INSERT INTO do_write DEFAULT VALUES;
@@ -19,23 +23,31 @@ step s2p: PREPARE TRANSACTION 'test1';
 step s3c: COMMIT;
 step s1init: <... completed>
 ?column?
-
+--------
 init    
+(1 row)
+
 step s1insert: INSERT INTO do_write DEFAULT VALUES;
 step s1start: SELECT data  FROM pg_logical_slot_get_changes('isolation_slot', NULL, NULL, 'include-xids', 'false', 'skip-empty-xacts', '1');
 data                                        
-
+--------------------------------------------
 BEGIN                                       
 table public.do_write: INSERT: id[integer]:2
 COMMIT                                      
+(3 rows)
+
 step s2cp: COMMIT PREPARED 'test1';
 step s1start: SELECT data  FROM pg_logical_slot_get_changes('isolation_slot', NULL, NULL, 'include-xids', 'false', 'skip-empty-xacts', '1');
 data                                        
-
+--------------------------------------------
 BEGIN                                       
 table public.do_write: INSERT: id[integer]:1
 PREPARE TRANSACTION 'test1'                 
 COMMIT PREPARED 'test1'                     
-?column?       
+(4 rows)
 
+?column?
+--------
 stop    
+(1 row)
+

src/test/isolation/expected/aborted-keyrevoke.out

@@ -5,14 +5,18 @@ step s1s: SAVEPOINT f;
 step s1u: UPDATE foo SET key = 2;
 step s1r: ROLLBACK TO f;
 step s1l: SELECT * FROM foo FOR KEY SHARE;
-key            value          
+key|value
+---+-----
+  1|    1
+(1 row)
 
-1              1              
 step s1c: COMMIT;
 step s2l: SELECT * FROM foo FOR KEY SHARE;
-key            value          
+key|value
+---+-----
+  1|    1
+(1 row)
 
-1              1              
 step s2c: COMMIT;
 
 starting permutation: s1s s1u s1r s1l s2l s1c s2c
@@ -20,13 +24,17 @@ step s1s: SAVEPOINT f;
 step s1u: UPDATE foo SET key = 2;
 step s1r: ROLLBACK TO f;
 step s1l: SELECT * FROM foo FOR KEY SHARE;
-key            value          
+key|value
+---+-----
+  1|    1
+(1 row)
 
-1              1              
 step s2l: SELECT * FROM foo FOR KEY SHARE;
-key            value          
+key|value
+---+-----
+  1|    1
+(1 row)
 
-1              1              
 step s1c: COMMIT;
 step s2c: COMMIT;
 
@@ -35,13 +43,17 @@ step s1s: SAVEPOINT f;
 step s1u: UPDATE foo SET key = 2;
 step s1r: ROLLBACK TO f;
 step s1l: SELECT * FROM foo FOR KEY SHARE;
-key            value          
+key|value
+---+-----
+  1|    1
+(1 row)
 
-1              1              
 step s2l: SELECT * FROM foo FOR KEY SHARE;
-key            value          
+key|value
+---+-----
+  1|    1
+(1 row)
 
-1              1              
 step s2c: COMMIT;
 step s1c: COMMIT;
 
@@ -50,13 +62,17 @@ step s1s: SAVEPOINT f;
 step s1u: UPDATE foo SET key = 2;
 step s1r: ROLLBACK TO f;
 step s2l: SELECT * FROM foo FOR KEY SHARE;
-key            value          
+key|value
+---+-----
+  1|    1
+(1 row)
 
-1              1              
 step s1l: SELECT * FROM foo FOR KEY SHARE;
-key            value          
+key|value
+---+-----
+  1|    1
+(1 row)
 
-1              1              
 step s1c: COMMIT;
 step s2c: COMMIT;
 
@@ -65,13 +81,17 @@ step s1s: SAVEPOINT f;
 step s1u: UPDATE foo SET key = 2;
 step s1r: ROLLBACK TO f;
 step s2l: SELECT * FROM foo FOR KEY SHARE;
-key            value          
+key|value
+---+-----
+  1|    1
+(1 row)
 
-1              1              
 step s1l: SELECT * FROM foo FOR KEY SHARE;
-key            value          
+key|value
+---+-----
+  1|    1
+(1 row)
 
-1              1              
 step s2c: COMMIT;
 step s1c: COMMIT;
 
@@ -80,14 +100,18 @@ step s1s: SAVEPOINT f;
 step s1u: UPDATE foo SET key = 2;
 step s1r: ROLLBACK TO f;
 step s2l: SELECT * FROM foo FOR KEY SHARE;
-key            value          
+key|value
+---+-----
+  1|    1
+(1 row)
 
-1              1              
 step s2c: COMMIT;
 step s1l: SELECT * FROM foo FOR KEY SHARE;
-key            value          
+key|value
+---+-----
+  1|    1
+(1 row)
 
-1              1              
 step s1c: COMMIT;
 
 starting permutation: s1s s1u s2l s1r s1l s1c s2c
@@ -96,13 +120,17 @@ step s1u: UPDATE foo SET key = 2;
 step s2l: SELECT * FROM foo FOR KEY SHARE; <waiting ...>
 step s1r: ROLLBACK TO f;
 step s2l: <... completed>
-key            value          
+key|value
+---+-----
+  1|    1
+(1 row)
 
-1              1              
 step s1l: SELECT * FROM foo FOR KEY SHARE;
-key            value          
+key|value
+---+-----
+  1|    1
+(1 row)
 
-1              1              
 step s1c: COMMIT;
 step s2c: COMMIT;
 
@@ -112,13 +140,17 @@ step s1u: UPDATE foo SET key = 2;
 step s2l: SELECT * FROM foo FOR KEY SHARE; <waiting ...>
 step s1r: ROLLBACK TO f;
 step s2l: <... completed>
-key            value          
+key|value
+---+-----
+  1|    1
+(1 row)
 
-1              1              
 step s1l: SELECT * FROM foo FOR KEY SHARE;
-key            value          
+key|value
+---+-----
+  1|    1
+(1 row)
 
-1              1              
 step s2c: COMMIT;
 step s1c: COMMIT;
 
@@ -128,89 +160,113 @@ step s1u: UPDATE foo SET key = 2;
 step s2l: SELECT * FROM foo FOR KEY SHARE; <waiting ...>
 step s1r: ROLLBACK TO f;
 step s2l: <... completed>
-key            value          
+key|value
+---+-----
+  1|    1
+(1 row)
 
-1              1              
 step s2c: COMMIT;
 step s1l: SELECT * FROM foo FOR KEY SHARE;
-key            value          
+key|value
+---+-----
+  1|    1
+(1 row)
 
-1              1              
 step s1c: COMMIT;
 
 starting permutation: s1s s2l s1u s2c s1r s1l s1c
 step s1s: SAVEPOINT f;
 step s2l: SELECT * FROM foo FOR KEY SHARE;
-key            value          
+key|value
+---+-----
+  1|    1
+(1 row)
 
-1              1              
 step s1u: UPDATE foo SET key = 2; <waiting ...>
 step s2c: COMMIT;
 step s1u: <... completed>
 step s1r: ROLLBACK TO f;
 step s1l: SELECT * FROM foo FOR KEY SHARE;
-key            value          
+key|value
+---+-----
+  1|    1
+(1 row)
 
-1              1              
 step s1c: COMMIT;
 
 starting permutation: s1s s2l s2c s1u s1r s1l s1c
 step s1s: SAVEPOINT f;
 step s2l: SELECT * FROM foo FOR KEY SHARE;
-key            value          
+key|value
+---+-----
+  1|    1
+(1 row)
 
-1              1              
 step s2c: COMMIT;
 step s1u: UPDATE foo SET key = 2;
 step s1r: ROLLBACK TO f;
 step s1l: SELECT * FROM foo FOR KEY SHARE;
-key            value          
+key|value
+---+-----
+  1|    1
+(1 row)
 
-1              1              
 step s1c: COMMIT;
 
 starting permutation: s2l s1s s1u s2c s1r s1l s1c
 step s2l: SELECT * FROM foo FOR KEY SHARE;
-key            value          
+key|value
+---+-----
+  1|    1
+(1 row)
 
-1              1              
 step s1s: SAVEPOINT f;
 step s1u: UPDATE foo SET key = 2; <waiting ...>
 step s2c: COMMIT;
 step s1u: <... completed>
 step s1r: ROLLBACK TO f;
 step s1l: SELECT * FROM foo FOR KEY SHARE;
-key            value          
+key|value
+---+-----
+  1|    1
+(1 row)
 
-1              1              
 step s1c: COMMIT;
 
 starting permutation: s2l s1s s2c s1u s1r s1l s1c
 step s2l: SELECT * FROM foo FOR KEY SHARE;
-key            value          
+key|value
+---+-----
+  1|    1
+(1 row)
 
-1              1              
 step s1s: SAVEPOINT f;
 step s2c: COMMIT;
 step s1u: UPDATE foo SET key = 2;
 step s1r: ROLLBACK TO f;
 step s1l: SELECT * FROM foo FOR KEY SHARE;
-key            value          
+key|value
+---+-----
+  1|    1
+(1 row)
 
-1              1              
 step s1c: COMMIT;
 
 starting permutation: s2l s2c s1s s1u s1r s1l s1c
 step s2l: SELECT * FROM foo FOR KEY SHARE;
-key            value          
+key|value
+---+-----
+  1|    1
+(1 row)
 
-1              1              
 step s2c: COMMIT;
 step s1s: SAVEPOINT f;
 step s1u: UPDATE foo SET key = 2;
 step s1r: ROLLBACK TO f;
 step s1l: SELECT * FROM foo FOR KEY SHARE;
-key            value          
+key|value
+---+-----
+  1|    1
+(1 row)
 
-1              1              
 step s1c: COMMIT;

src/test/isolation/expected/fk-partitioned-2.out

@@ -15,8 +15,10 @@ step s1b: begin;
 step s1d: delete from ppk where a = 1;
 step s2bs: begin isolation level serializable; select 1;
 ?column?
+--------
+       1
+(1 row)
 
-1              
 step s2i: insert into pfk values (1); <waiting ...>
 step s1c: commit;
 step s2i: <... completed>
@@ -37,8 +39,10 @@ starting permutation: s1b s2bs s1d s2i s1c s2c
 step s1b: begin;
 step s2bs: begin isolation level serializable; select 1;
 ?column?
+--------
+       1
+(1 row)
 
-1              
 step s1d: delete from ppk where a = 1;
 step s2i: insert into pfk values (1); <waiting ...>
 step s1c: commit;
@@ -60,8 +64,10 @@ starting permutation: s1b s2bs s2i s1d s2c s1c
 step s1b: begin;
 step s2bs: begin isolation level serializable; select 1;
 ?column?
+--------
+       1
+(1 row)
 
-1              
 step s2i: insert into pfk values (1);
 step s1d: delete from ppk where a = 1; <waiting ...>
 step s2c: commit;