text: Parsed test spec with 2 sessions
  
  starting permutation: wxry1 c1 r2 wyrx2 c2
  step wxry1: INSERT INTO child (parent_id) VALUES (0);
  step c1: COMMIT;
  step r2: SELECT TRUE;
  bool           
  
  t              
  step wyrx2: DELETE FROM parent WHERE parent_id = 0;
  ERROR:  child row exists
  step c2: COMMIT;
  
  starting permutation: wxry1 r2 c1 wyrx2 c2
  step wxry1: INSERT INTO child (parent_id) VALUES (0);
  step r2: SELECT TRUE;
  bool           
  
  t              
  step c1: COMMIT;
  step wyrx2: DELETE FROM parent WHERE parent_id = 0;
  ERROR:  could not serialize access due to read/write dependencies among transactions
  step c2: COMMIT;
  
  starting permutation: wxry1 r2 wyrx2 c1 c2
  step wxry1: INSERT INTO child (parent_id) VALUES (0);
  step r2: SELECT TRUE;
  bool           
  
  t              
  step wyrx2: DELETE FROM parent WHERE parent_id = 0;
  step c1: COMMIT;
  step c2: COMMIT;
  ERROR:  could not serialize access due to read/write dependencies among transactions
  
  starting permutation: wxry1 r2 wyrx2 c2 c1
  step wxry1: INSERT INTO child (parent_id) VALUES (0);
  step r2: SELECT TRUE;
  bool           
  
  t              
  step wyrx2: DELETE FROM parent WHERE parent_id = 0;
  step c2: COMMIT;
  step c1: COMMIT;
  ERROR:  could not serialize access due to read/write dependencies among transactions
  
  starting permutation: r2 wxry1 c1 wyrx2 c2
  step r2: SELECT TRUE;
  bool           
  
  t              
  step wxry1: INSERT INTO child (parent_id) VALUES (0);
  step c1: COMMIT;
  step wyrx2: DELETE FROM parent WHERE parent_id = 0;
  ERROR:  could not serialize access due to read/write dependencies among transactions
  step c2: COMMIT;
  
  starting permutation: r2 wxry1 wyrx2 c1 c2
  step r2: SELECT TRUE;
  bool           
  
  t              
  step wxry1: INSERT INTO child (parent_id) VALUES (0);
  step wyrx2: DELETE FROM parent WHERE parent_id = 0;
  step c1: COMMIT;
  step c2: COMMIT;
  ERROR:  could not serialize access due to read/write dependencies among transactions
  
  starting permutation: r2 wxry1 wyrx2 c2 c1
  step r2: SELECT TRUE;
  bool           
  
  t              
  step wxry1: INSERT INTO child (parent_id) VALUES (0);
  step wyrx2: DELETE FROM parent WHERE parent_id = 0;
  step c2: COMMIT;
  step c1: COMMIT;
  ERROR:  could not serialize access due to read/write dependencies among transactions
  
  starting permutation: r2 wyrx2 wxry1 c1 c2
  step r2: SELECT TRUE;
  bool           
  
  t              
  step wyrx2: DELETE FROM parent WHERE parent_id = 0;
  step wxry1: INSERT INTO child (parent_id) VALUES (0);
  step c1: COMMIT;
  step c2: COMMIT;
  ERROR:  could not serialize access due to read/write dependencies among transactions
  
  starting permutation: r2 wyrx2 wxry1 c2 c1
  step r2: SELECT TRUE;
  bool           
  
  t              
  step wyrx2: DELETE FROM parent WHERE parent_id = 0;
  step wxry1: INSERT INTO child (parent_id) VALUES (0);
  step c2: COMMIT;
  step c1: COMMIT;
  ERROR:  could not serialize access due to read/write dependencies among transactions
  
  starting permutation: r2 wyrx2 c2 wxry1 c1
  step r2: SELECT TRUE;
  bool           
  
  t              
  step wyrx2: DELETE FROM parent WHERE parent_id = 0;
  step c2: COMMIT;
  step wxry1: INSERT INTO child (parent_id) VALUES (0);
  ERROR:  parent row missing
  step c1: COMMIT;
  