uniqueidentifier字段 唯一值的问题

Question

执行以下语句N亿次，两个表中fa与fb中的值永远不会相同吗？insert into ta (fa) select newID()
insert into tb (fb) select newID()谢谢

Answer 1

谢谢！除以下写法，另外还有其他的方法返回newID()生产的值吗？
declare @NV uniqueidentifier
select @NV=newID()
insert into ta select @NV

Answer 2

使用：NEWSEQUENTIALID ( )这个函数创建的随机数较为稳定。

Answer 3

是否可以得到NEWSEQUENTIALID()产生的值呢，我需要在另外的表中应用到该值的

Answer 4

总感觉guid、uuid之类的算法，还是有很低的概率会重复的

Answer 5

declare @s varchar(100);
set @s=NEWSEQUENTIALID()

Answer 6

哦，还真是，与newid()不一样！declare @t table(fa uniqueidentifier default NEWSEQUENTIALID() ,fid int) 
declare @s uniqueidentifier; --varchar(100);insert @t (fid) values (1);
select @s=fa from @tset @s=newid()
print @s
print @s

Answer 7

declare @t table(fa uniqueidentifier default NEWSEQUENTIALID() ,fid int) 
declare @s uniqueidentifier; --varchar(100);insert @t (fid) values (1);
select @s=fa from @t
print @sset @s=newid()
print @s

Answer 8

declare @s uniqueidentifier;
set @s=NEWID() 
select @s
--or
select newid()

Answer 9

NEWSEQUENTIALID的结果，同一台机做了100次，后面4段都没变：
 NEWSEQUENTIALID                     - newid
31D4E1D4-7138-E211-8197-E41F132ED94A - 71FC8073-1690-430B-BBD3-3A3177FD726A
32D4E1D4-7138-E211-8197-E41F132ED94A - E89160D4-B7BE-4C91-B138-AB354C125543
33D4E1D4-7138-E211-8197-E41F132ED94A - CBB38832-CBBA-41E8-844C-1A2C4D659503
34D4E1D4-7138-E211-8197-E41F132ED94A - 3D1948A5-7C27-4E08-9DEF-0A65753526F4
35D4E1D4-7138-E211-8197-E41F132ED94A - 6CF06E67-2F78-4BEF-A340-2F7E0ED281E1
36D4E1D4-7138-E211-8197-E41F132ED94A - E6CF72D2-5EED-4691-BF9A-1274CD772540
37D4E1D4-7138-E211-8197-E41F132ED94A - B0906A73-CD32-45E6-A61B-D50B41C4A6D7
38D4E1D4-7138-E211-8197-E41F132ED94A - 3A8930F4-39BF-4B4B-8533-2D17D0FB239B
39D4E1D4-7138-E211-8197-E41F132ED94A - 99EE8DC3-3D71-46E7-9949-3B65C2D574CB
3AD4E1D4-7138-E211-8197-E41F132ED94A - 668ADCA9-1749-4B18-A2F3-47FE33178A12
3BD4E1D4-7138-E211-8197-E41F132ED94A - BC3F2C0A-F2D5-4F11-A743-E0F5CFF409E3
3CD4E1D4-7138-E211-8197-E41F132ED94A - 42B5819E-955F-4E13-9891-B2C397B0B71C
3DD4E1D4-7138-E211-8197-E41F132ED94A - E6327FB5-929F-4FBA-9EA0-127AF0492572
3ED4E1D4-7138-E211-8197-E41F132ED94A - DF411DFF-3322-4088-AAD2-E3EF3207A27A
3FD4E1D4-7138-E211-8197-E41F132ED94A - 83D6285B-41D6-4EBA-AFE0-C38ECB90119C
40D4E1D4-7138-E211-8197-E41F132ED94A - B435214C-59D1-402F-8C38-85472094A8AB
41D4E1D4-7138-E211-8197-E41F132ED94A - F677BFD6-DC19-4775-83BC-AFBD068620B4
42D4E1D4-7138-E211-8197-E41F132ED94A - 0D78A580-77B0-4EF8-8633-00CE90660042
43D4E1D4-7138-E211-8197-E41F132ED94A - 7020C75A-5F29-4D11-85AE-55AAF986B5AE
44D4E1D4-7138-E211-8197-E41F132ED94A - 003A0EB9-E277-4018-97AC-4C17CA1F6188
45D4E1D4-7138-E211-8197-E41F132ED94A - 75370D1C-FFCD-49CC-B841-67D1433C4478
46D4E1D4-7138-E211-8197-E41F132ED94A - 3A4FABB3-1FB4-42D9-BAA8-3973EB7FDFE6
47D4E1D4-7138-E211-8197-E41F132ED94A - 68DE06E9-F7C4-4ECB-9237-28FF9F490ABC
48D4E1D4-7138-E211-8197-E41F132ED94A - 3B075F1F-E503-4EAE-B55F-67EBA1B564D0
49D4E1D4-7138-E211-8197-E41F132ED94A - 25C951BF-8EA0-4038-B6BE-A0F51AF14CF4
4AD4E1D4-7138-E211-8197-E41F132ED94A - 6DFECEBF-382D-4049-A082-544039F7D57C
4BD4E1D4-7138-E211-8197-E41F132ED94A - 7053CA20-8967-4387-89AC-FC205B1060FF
4CD4E1D4-7138-E211-8197-E41F132ED94A - 04F9AA5C-DAAE-499C-A46C-6AB13495EB8D
4DD4E1D4-7138-E211-8197-E41F132ED94A - F76978F1-D803-4EA8-8FD7-2210B3063755
4ED4E1D4-7138-E211-8197-E41F132ED94A - C6DA2044-3B16-459A-8B65-4928AA419623
4FD4E1D4-7138-E211-8197-E41F132ED94A - 2764F77B-9FC3-43EA-B83F-28AC2CDC94EC
50D4E1D4-7138-E211-8197-E41F132ED94A - 7476542A-5835-4B2B-895E-7E87FDEEDCB6
51D4E1D4-7138-E211-8197-E41F132ED94A - 02B66DE6-9990-4F31-9914-EF2F662FD8DE
52D4E1D4-7138-E211-8197-E41F132ED94A - F307CEA4-D555-4748-8111-E360A27B1D67
53D4E1D4-7138-E211-8197-E41F132ED94A - 69006B4F-C2E6-4082-9C43-ABFEF24AF441
54D4E1D4-7138-E211-8197-E41F132ED94A - 4D0E17EA-1C38-46F1-9D32-7F545DCAD5CB
55D4E1D4-7138-E211-8197-E41F132ED94A - 44682D1B-A338-43DE-B205-8B633D7B6969
56D4E1D4-7138-E211-8197-E41F132ED94A - 65FFCA1A-A843-44BC-9D3D-53DBBEA3F25F
57D4E1D4-7138-E211-8197-E41F132ED94A - B38C268E-EC57-4E4E-907F-F7CB0F9A5184
58D4E1D4-7138-E211-8197-E41F132ED94A - 7D53CEC6-3E77-40FD-9E3C-63AA6E20E572
59D4E1D4-7138-E211-8197-E41F132ED94A - 6315DF95-00E0-4CA1-AFF4-C618FA4BA434
5AD4E1D4-7138-E211-8197-E41F132ED94A - 8B07808B-514D-4EC7-BDDD-CCACBD5667A2
5BD4E1D4-7138-E211-8197-E41F132ED94A - 3ACA2D9D-6FC6-47CA-9F44-824F9383B1DA
5CD4E1D4-7138-E211-8197-E41F132ED94A - E77620C4-B772-4D39-8F69-52D716548E97
5DD4E1D4-7138-E211-8197-E41F132ED94A - 31025218-7DCB-4321-B43A-8BC12A438552
5ED4E1D4-7138-E211-8197-E41F132ED94A - 14A640F0-2833-439D-9943-14CA93FE25EA
5FD4E1D4-7138-E211-8197-E41F132ED94A - 2B4BD553-EF60-4D96-BA2D-C3F45205AB40
60D4E1D4-7138-E211-8197-E41F132ED94A - 1EB38BD3-7AAA-47F6-B6C1-F8FA582631E4
61D4E1D4-7138-E211-8197-E41F132ED94A - ED84ACAE-C0FE-4F74-8A61-48B41579C336
62D4E1D4-7138-E211-8197-E41F132ED94A - 95CE60AF-762D-42A1-8123-09F7A45A0842
63D4E1D4-7138-E211-8197-E41F132ED94A - 66E78415-2573-4C4C-8F1C-9C60CFC70BE6
64D4E1D4-7138-E211-8197-E41F132ED94A - C6BA69DE-2EE1-422E-9B51-1BE5809952C3
65D4E1D4-7138-E211-8197-E41F132ED94A - BC450BA0-B45F-4DE3-9979-06F1360B3323
66D4E1D4-7138-E211-8197-E41F132ED94A - DE8ABE49-6CE0-4CAE-8C0B-76E74A1C6748
67D4E1D4-7138-E211-8197-E41F132ED94A - 9065414E-127B-4683-B4B9-9A3E100655E5
68D4E1D4-7138-E211-8197-E41F132ED94A - 1321DFF9-FC5C-4447-935A-BB492AD4B779
69D4E1D4-7138-E211-8197-E41F132ED94A - BE3BDE03-9628-427D-8949-861186C6F120
6AD4E1D4-7138-E211-8197-E41F132ED94A - 9A5177E0-DB53-4F48-B5DF-D8ABCDB50D08
6BD4E1D4-7138-E211-8197-E41F132ED94A - 47E0C629-733A-473A-90B6-B50F98E3D151
6CD4E1D4-7138-E211-8197-E41F132ED94A - 614C9BC3-F462-4687-AE99-9A8BD41CD2F9
6DD4E1D4-7138-E211-8197-E41F132ED94A - C75D7CA8-16B7-43E6-84FB-AC38817C444A
6ED4E1D4-7138-E211-8197-E41F132ED94A - 76872570-2720-4E0F-8077-D1CF2805EE77
6FD4E1D4-7138-E211-8197-E41F132ED94A - DEDDE728-95A4-4E9B-B946-9E1EF05BE128
70D4E1D4-7138-E211-8197-E41F132ED94A - BC779E56-BA3D-4A56-BEB0-BA2A459B6E49
71D4E1D4-7138-E211-8197-E41F132ED94A - 54F92162-A777-43B1-ABAB-BB0055AB6095
72D4E1D4-7138-E211-8197-E41F132ED94A - DCB28DEC-0427-4247-947E-9219D20D9D01
73D4E1D4-7138-E211-8197-E41F132ED94A - 31309C3A-B730-4EA0-BE16-D9D83686A7E4
74D4E1D4-7138-E211-8197-E41F132ED94A - BCCDDD67-D109-4817-B82D-6C6D9DED5A55
75D4E1D4-7138-E211-8197-E41F132ED94A - 63542E2B-A57D-4E69-94D2-E4DE640176AD
76D4E1D4-7138-E211-8197-E41F132ED94A - 552EF778-CB07-454B-ADAC-E84995E605D2
77D4E1D4-7138-E211-8197-E41F132ED94A - 3CA3D0FD-4915-4C1C-BC96-881E2CEA08FC
78D4E1D4-7138-E211-8197-E41F132ED94A - FE245696-02A2-4B7F-BF63-9900C301CF5B
79D4E1D4-7138-E211-8197-E41F132ED94A - A33604F6-9580-4260-87A1-5669EC84F16C
7AD4E1D4-7138-E211-8197-E41F132ED94A - BFB0D6FD-1B95-4705-BA57-82308CB1203E
7BD4E1D4-7138-E211-8197-E41F132ED94A - B23BEA3F-DA18-4A08-A280-A8B3CD6ADB08
7CD4E1D4-7138-E211-8197-E41F132ED94A - EB9B6D12-0CB2-4B3C-B3C9-48743E2347DB
7DD4E1D4-7138-E211-8197-E41F132ED94A - B9F8F5BE-4076-4E35-B2D3-A70DD0D7C21C
7ED4E1D4-7138-E211-8197-E41F132ED94A - 55ADE3D5-C19D-49FF-B6B8-76C209A76EB6
7FD4E1D4-7138-E211-8197-E41F132ED94A - 56710E17-E004-484D-B52A-C260F9DEB358
80D4E1D4-7138-E211-8197-E41F132ED94A - 1F56A2F9-F8FD-4A5B-AF9C-1B80225DA007
81D4E1D4-7138-E211-8197-E41F132ED94A - DD514A19-402D-4935-B95C-9B3CFB28F32D
82D4E1D4-7138-E211-8197-E41F132ED94A - 33C97746-D62D-4A1B-8DBB-7E0B59714000
83D4E1D4-7138-E211-8197-E41F132ED94A - 2F684FDA-2491-41A7-940E-7BD386168621
84D4E1D4-7138-E211-8197-E41F132ED94A - 036AC41D-F784-4405-A5F4-043C7E094BF7
85D4E1D4-7138-E211-8197-E41F132ED94A - 812653FD-F42E-458A-B174-44323D6392A3
86D4E1D4-7138-E211-8197-E41F132ED94A - 26956A02-E28C-4247-BCF5-40200C6B4632
87D4E1D4-7138-E211-8197-E41F132ED94A - 0D79079F-BB0C-49E0-ABDD-6823602F6D31
88D4E1D4-7138-E211-8197-E41F132ED94A - 8F77E324-FB30-4171-9D7B-FB6D37395C0F
89D4E1D4-7138-E211-8197-E41F132ED94A - A0A7C4E8-362E-4EB2-842D-05CD489EE86A
8AD4E1D4-7138-E211-8197-E41F132ED94A - A8F4818E-37A9-4276-9667-C784D56E5C0A
8BD4E1D4-7138-E211-8197-E41F132ED94A - AAE404C4-B491-43B4-8198-EAFDE0C7907E
8CD4E1D4-7138-E211-8197-E41F132ED94A - A8032CA4-AF17-4BD5-B3CC-973E3D6926D3
8DD4E1D4-7138-E211-8197-E41F132ED94A - 9A9ED454-D224-4B68-8EEC-BA13B2705E9B
8ED4E1D4-7138-E211-8197-E41F132ED94A - E4C6A315-39A1-45C3-9AC8-5B3EA707540C
8FD4E1D4-7138-E211-8197-E41F132ED94A - 8F1F460C-F878-4FB2-8D2F-550FC1E6B57E
90D4E1D4-7138-E211-8197-E41F132ED94A - 1830301C-87FC-4270-9A8A-4A9899FD938B
91D4E1D4-7138-E211-8197-E41F132ED94A - 60F086F9-1999-4C1A-B88A-960B4C3C7C73
92D4E1D4-7138-E211-8197-E41F132ED94A - F7055BCF-652B-4238-B4E8-42CF00640137
93D4E1D4-7138-E211-8197-E41F132ED94A - BF43D884-7E2C-4666-BDA7-55624A2E74A6

Answer 10

但是newid没顺序NEWSEQUENTIALID保证了顺序，肯定牺牲了唯一性的强度，另外，如果多个库、表的数据合并后，顺序也乱了，如果递增的信息在最后一段，好像更好一点