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-- txid_snapshot data type and related functions
-- i/o
select '12:13:'::txid_snapshot;
txid_snapshot
---------------
12:13:
(1 row)
select '12:18:14,16'::txid_snapshot;
txid_snapshot
---------------
12:18:14,16
(1 row)
select '12:16:14,14'::txid_snapshot;
txid_snapshot
---------------
12:16:14
(1 row)
-- errors
select '31:12:'::txid_snapshot;
ERROR: invalid input syntax for type txid_snapshot: "31:12:"
LINE 1: select '31:12:'::txid_snapshot;
^
select '0:1:'::txid_snapshot;
ERROR: invalid input syntax for type txid_snapshot: "0:1:"
LINE 1: select '0:1:'::txid_snapshot;
^
select '12:13:0'::txid_snapshot;
ERROR: invalid input syntax for type txid_snapshot: "12:13:0"
LINE 1: select '12:13:0'::txid_snapshot;
^
select '12:16:14,13'::txid_snapshot;
ERROR: invalid input syntax for type txid_snapshot: "12:16:14,13"
LINE 1: select '12:16:14,13'::txid_snapshot;
^
create temp table snapshot_test (
nr integer,
snap txid_snapshot
);
insert into snapshot_test values (1, '12:13:');
insert into snapshot_test values (2, '12:20:13,15,18');
insert into snapshot_test values (3, '100001:100009:100005,100007,100008');
insert into snapshot_test values (4, '100:150:101,102,103,104,105,106,107,108,109,110,111,112,113,114,115,116,117,118,119,120,121,122,123,124,125,126,127,128,129,130,131');
select snap from snapshot_test order by nr;
snap
-------------------------------------------------------------------------------------------------------------------------------------
12:13:
12:20:13,15,18
100001:100009:100005,100007,100008
100:150:101,102,103,104,105,106,107,108,109,110,111,112,113,114,115,116,117,118,119,120,121,122,123,124,125,126,127,128,129,130,131
(4 rows)
select txid_snapshot_xmin(snap),
txid_snapshot_xmax(snap),
txid_snapshot_xip(snap)
from snapshot_test order by nr;
txid_snapshot_xmin | txid_snapshot_xmax | txid_snapshot_xip
--------------------+--------------------+-------------------
12 | 20 | 13
12 | 20 | 15
12 | 20 | 18
100001 | 100009 | 100005
100001 | 100009 | 100007
100001 | 100009 | 100008
100 | 150 | 101
100 | 150 | 102
100 | 150 | 103
100 | 150 | 104
100 | 150 | 105
100 | 150 | 106
100 | 150 | 107
100 | 150 | 108
100 | 150 | 109
100 | 150 | 110
100 | 150 | 111
100 | 150 | 112
100 | 150 | 113
100 | 150 | 114
100 | 150 | 115
100 | 150 | 116
100 | 150 | 117
100 | 150 | 118
100 | 150 | 119
100 | 150 | 120
100 | 150 | 121
100 | 150 | 122
100 | 150 | 123
100 | 150 | 124
100 | 150 | 125
100 | 150 | 126
100 | 150 | 127
100 | 150 | 128
100 | 150 | 129
100 | 150 | 130
100 | 150 | 131
(37 rows)
select id, txid_visible_in_snapshot(id, snap)
from snapshot_test, generate_series(11, 21) id
where nr = 2;
id | txid_visible_in_snapshot
----+--------------------------
11 | t
12 | t
13 | f
14 | t
15 | f
16 | t
17 | t
18 | f
19 | t
20 | f
21 | f
(11 rows)
-- test bsearch
select id, txid_visible_in_snapshot(id, snap)
from snapshot_test, generate_series(90, 160) id
where nr = 4;
id | txid_visible_in_snapshot
-----+--------------------------
90 | t
91 | t
92 | t
93 | t
94 | t
95 | t
96 | t
97 | t
98 | t
99 | t
100 | t
101 | f
102 | f
103 | f
104 | f
105 | f
106 | f
107 | f
108 | f
109 | f
110 | f
111 | f
112 | f
113 | f
114 | f
115 | f
116 | f
117 | f
118 | f
119 | f
120 | f
121 | f
122 | f
123 | f
124 | f
125 | f
126 | f
127 | f
128 | f
129 | f
130 | f
131 | f
132 | t
133 | t
134 | t
135 | t
136 | t
137 | t
138 | t
139 | t
140 | t
141 | t
142 | t
143 | t
144 | t
145 | t
146 | t
147 | t
148 | t
149 | t
150 | f
151 | f
152 | f
153 | f
154 | f
155 | f
156 | f
157 | f
158 | f
159 | f
160 | f
(71 rows)
-- test current values also
select txid_current() >= txid_snapshot_xmin(txid_current_snapshot());
?column?
----------
t
(1 row)
-- we can't assume current is always less than xmax, however
select txid_visible_in_snapshot(txid_current(), txid_current_snapshot());
txid_visible_in_snapshot
--------------------------
f
(1 row)
-- test 64bitness
select txid_snapshot '1000100010001000:1000100010001100:1000100010001012,1000100010001013';
txid_snapshot
---------------------------------------------------------------------
1000100010001000:1000100010001100:1000100010001012,1000100010001013
(1 row)
select txid_visible_in_snapshot('1000100010001012', '1000100010001000:1000100010001100:1000100010001012,1000100010001013');
txid_visible_in_snapshot
--------------------------
f
(1 row)
select txid_visible_in_snapshot('1000100010001015', '1000100010001000:1000100010001100:1000100010001012,1000100010001013');
txid_visible_in_snapshot
--------------------------
t
(1 row)
-- test 64bit overflow
SELECT txid_snapshot '1:9223372036854775807:3';
txid_snapshot
-------------------------
1:9223372036854775807:3
(1 row)
SELECT txid_snapshot '1:9223372036854775808:3';
ERROR: invalid input syntax for type txid_snapshot: "1:9223372036854775808:3"
LINE 1: SELECT txid_snapshot '1:9223372036854775808:3';
^
|
