TSIDs strike the perfect balance between integers and UUIDs for most databases

https://www.foxhound.systems/blog/time-sorted-unique-identifiers/

自增bigint 优点有序，可预测(CPU prefetch)，数量大，表征时间，类似create_at，可读性好，方便看/定位缺点，坦克问题：被摸到数据信息（简单hash混淆一下），多机时序问题（id不同）

UUID UUIDv4 8-4-4-4-12 优点随机自带混淆，跨系统缺点随机，index无法预测从而变成memory bound，体积大，浪费, 可读性差（简单hash简化一下？）

好消息，UUIDv7 https://www.ietf.org/archive/id/draft-peabody-dispatch-new-uuid-format-04.html#v7 UUID version 7 features a time-ordered value field derived from the widely implemented and well known Unix Epoch timestamp source, the number of milliseconds seconds since midnight 1 Jan 1970 UTC, leap seconds excluded. As well as improved entropy characteristics over versions 1 or 6. Implementations SHOULD utilize UUID version 7 over UUID version 1 and 6 if possible.

 0                   1                   2                   3
 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
|                           unix_ts_ms                          |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
|          unix_ts_ms           |  ver  |       rand_a          |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
|var|                        rand_b                             |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
|                            rand_b                             |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+

TSID 结合snowflake ID和ULID

ULID能排序，但不递增

Snowflake递增，但不严格排序

有着snaoflakeid一样的问题，70年

一个实现，https://github.sheincorp.cn/f4b6a3/tsid-creator

支持内置base32编码支持 https://www.crockford.com/base32.html 可读性好

横向对比

Feature	Auto-incr. Integers	UUIDs	TSIDs
Key Type	Variable size integer	128-bit integer	64-bit integer
Uniqueness	Unique within a database	Universally unique	Unique across nodes
Predictability	Predictable sequence	Unpredictable	Unpredictable
Space Efficiency	High (small size)	Low(large size)	Moderate(larger than integers but smaller than UUIDs)
Data locality	High(sequential increment)	Low(random order)	High(time-sorted with random component)
Performance	High(efficient indexing, inserts, reads)	Poor(inefficient inserts, scattered indexes, read penalty)	High(similar to integers)
Readability	High(simple numbers)	Low(32 character strings)	Moderate(13 character strings)
Chronological Sorting	Yes, implicit(based on sequence)	No inherent order	Yes, time-sorted(based on time component)
Multi-node Generation	Not feasible	Easily feasible	Feasible with node IDs
Security (Inference Risk)	High(German Tank Problem)	Low(no inference)	Low(no inference)
Ease of Implementation	High(natively supported)	Moderate(varies by database)	Low(least support, requires function implementation, managing node IDs)
Scalability	Varies(limited by integer type)	High(no practical limit)	High(at least ~70 years, limited by timestamp size)
Migration Flexibility	Moderate(can change to larger integer type)	Low(hard to change key type)	High(drop-in compatible with integers)

wanghenshui / wanghenshui.github.io

TSIDs strike the perfect balance between integers and UUIDs for most databases #108