1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
|
Parsed test spec with 2 sessions
starting permutation: s1_begin s1_tuplock1 s2_rowlocks s1_commit
step s1_begin: BEGIN;
step s1_tuplock1: SELECT * FROM multixact_conflict FOR KEY SHARE;
a|b
-+-
1|2
3|4
(2 rows)
step s2_rowlocks: SELECT locked_row, multi, modes FROM pgrowlocks('multixact_conflict');
locked_row|multi|modes
----------+-----+-----------------
(0,1) |f |{"For Key Share"}
(0,2) |f |{"For Key Share"}
(2 rows)
step s1_commit: COMMIT;
starting permutation: s1_begin s1_tuplock2 s2_rowlocks s1_commit
step s1_begin: BEGIN;
step s1_tuplock2: SELECT * FROM multixact_conflict FOR SHARE;
a|b
-+-
1|2
3|4
(2 rows)
step s2_rowlocks: SELECT locked_row, multi, modes FROM pgrowlocks('multixact_conflict');
locked_row|multi|modes
----------+-----+-------------
(0,1) |f |{"For Share"}
(0,2) |f |{"For Share"}
(2 rows)
step s1_commit: COMMIT;
starting permutation: s1_begin s1_tuplock3 s2_rowlocks s1_commit
step s1_begin: BEGIN;
step s1_tuplock3: SELECT * FROM multixact_conflict FOR NO KEY UPDATE;
a|b
-+-
1|2
3|4
(2 rows)
step s2_rowlocks: SELECT locked_row, multi, modes FROM pgrowlocks('multixact_conflict');
locked_row|multi|modes
----------+-----+---------------------
(0,1) |f |{"For No Key Update"}
(0,2) |f |{"For No Key Update"}
(2 rows)
step s1_commit: COMMIT;
starting permutation: s1_begin s1_tuplock4 s2_rowlocks s1_commit
step s1_begin: BEGIN;
step s1_tuplock4: SELECT * FROM multixact_conflict FOR UPDATE;
a|b
-+-
1|2
3|4
(2 rows)
step s2_rowlocks: SELECT locked_row, multi, modes FROM pgrowlocks('multixact_conflict');
locked_row|multi|modes
----------+-----+--------------
(0,1) |f |{"For Update"}
(0,2) |f |{"For Update"}
(2 rows)
step s1_commit: COMMIT;
starting permutation: s1_begin s1_updatea s2_rowlocks s1_commit
step s1_begin: BEGIN;
step s1_updatea: UPDATE multixact_conflict SET a = 10 WHERE a = 1;
step s2_rowlocks: SELECT locked_row, multi, modes FROM pgrowlocks('multixact_conflict');
locked_row|multi|modes
----------+-----+--------
(0,1) |f |{Update}
(1 row)
step s1_commit: COMMIT;
starting permutation: s1_begin s1_updateb s2_rowlocks s1_commit
step s1_begin: BEGIN;
step s1_updateb: UPDATE multixact_conflict SET b = 11 WHERE b = 4;
step s2_rowlocks: SELECT locked_row, multi, modes FROM pgrowlocks('multixact_conflict');
locked_row|multi|modes
----------+-----+-----------------
(0,2) |f |{"No Key Update"}
(1 row)
step s1_commit: COMMIT;
starting permutation: s1_begin s1_lcksvpt s1_tuplock1 s2_rowlocks s1_commit
step s1_begin: BEGIN;
step s1_lcksvpt: SELECT * FROM multixact_conflict FOR KEY SHARE; SAVEPOINT s;
a|b
-+-
1|2
3|4
(2 rows)
step s1_tuplock1: SELECT * FROM multixact_conflict FOR KEY SHARE;
a|b
-+-
1|2
3|4
(2 rows)
step s2_rowlocks: SELECT locked_row, multi, modes FROM pgrowlocks('multixact_conflict');
locked_row|multi|modes
----------+-----+-----------------
(0,1) |f |{"For Key Share"}
(0,2) |f |{"For Key Share"}
(2 rows)
step s1_commit: COMMIT;
starting permutation: s1_begin s1_lcksvpt s1_tuplock2 s2_rowlocks s1_commit
step s1_begin: BEGIN;
step s1_lcksvpt: SELECT * FROM multixact_conflict FOR KEY SHARE; SAVEPOINT s;
a|b
-+-
1|2
3|4
(2 rows)
step s1_tuplock2: SELECT * FROM multixact_conflict FOR SHARE;
a|b
-+-
1|2
3|4
(2 rows)
step s2_rowlocks: SELECT locked_row, multi, modes FROM pgrowlocks('multixact_conflict');
locked_row|multi|modes
----------+-----+-------------------
(0,1) |t |{"Key Share",Share}
(0,2) |t |{"Key Share",Share}
(2 rows)
step s1_commit: COMMIT;
starting permutation: s1_begin s1_lcksvpt s1_tuplock3 s2_rowlocks s1_commit
step s1_begin: BEGIN;
step s1_lcksvpt: SELECT * FROM multixact_conflict FOR KEY SHARE; SAVEPOINT s;
a|b
-+-
1|2
3|4
(2 rows)
step s1_tuplock3: SELECT * FROM multixact_conflict FOR NO KEY UPDATE;
a|b
-+-
1|2
3|4
(2 rows)
step s2_rowlocks: SELECT locked_row, multi, modes FROM pgrowlocks('multixact_conflict');
locked_row|multi|modes
----------+-----+---------------------------------
(0,1) |t |{"Key Share","For No Key Update"}
(0,2) |t |{"Key Share","For No Key Update"}
(2 rows)
step s1_commit: COMMIT;
starting permutation: s1_begin s1_lcksvpt s1_tuplock4 s2_rowlocks s1_commit
step s1_begin: BEGIN;
step s1_lcksvpt: SELECT * FROM multixact_conflict FOR KEY SHARE; SAVEPOINT s;
a|b
-+-
1|2
3|4
(2 rows)
step s1_tuplock4: SELECT * FROM multixact_conflict FOR UPDATE;
a|b
-+-
1|2
3|4
(2 rows)
step s2_rowlocks: SELECT locked_row, multi, modes FROM pgrowlocks('multixact_conflict');
locked_row|multi|modes
----------+-----+--------------------------
(0,1) |t |{"Key Share","For Update"}
(0,2) |t |{"Key Share","For Update"}
(2 rows)
step s1_commit: COMMIT;
starting permutation: s1_begin s1_lcksvpt s1_updatea s2_rowlocks s1_commit
step s1_begin: BEGIN;
step s1_lcksvpt: SELECT * FROM multixact_conflict FOR KEY SHARE; SAVEPOINT s;
a|b
-+-
1|2
3|4
(2 rows)
step s1_updatea: UPDATE multixact_conflict SET a = 10 WHERE a = 1;
step s2_rowlocks: SELECT locked_row, multi, modes FROM pgrowlocks('multixact_conflict');
locked_row|multi|modes
----------+-----+--------------------
(0,1) |t |{"Key Share",Update}
(0,2) |f |{"For Key Share"}
(2 rows)
step s1_commit: COMMIT;
starting permutation: s1_begin s1_lcksvpt s1_updateb s2_rowlocks s1_commit
step s1_begin: BEGIN;
step s1_lcksvpt: SELECT * FROM multixact_conflict FOR KEY SHARE; SAVEPOINT s;
a|b
-+-
1|2
3|4
(2 rows)
step s1_updateb: UPDATE multixact_conflict SET b = 11 WHERE b = 4;
step s2_rowlocks: SELECT locked_row, multi, modes FROM pgrowlocks('multixact_conflict');
locked_row|multi|modes
----------+-----+-----------------------------
(0,1) |f |{"For Key Share"}
(0,2) |t |{"Key Share","No Key Update"}
(2 rows)
step s1_commit: COMMIT;
|
