What's UUID with ULID? What are they solving?
The generation of the only global identifier (ID) in distributed systems and modern database design is a core task. Traditional self-inflated numbers ID Although simple, there are key conflicts and security risks in the case of a split-bank, microservice structures and the need to hide internal data volume.
UUID (Universally Unique Identifier) is a set of 128-bit identifiers. Most common UUID v4 It is based almost exclusively on random numbers and provides a very high degree of uniqueness. However, the randomity of UUID v4 resulted in it in the database B-Tree Poor performance in the index can lead to serious page fragmentation and reduced performance.
UUID v7 and ULID (Universally Unique Lexicographically Sortable Identifier) It was born to solve this problem. They're on ID. , which is then inserted in the beginning of the time stamp in milliseconds to give it "time-ordered". This means that the new generation of IDs is always bigger than the old ones. ID, which is capable of sequentially inserting database indexes, greatly enhances the database's write-off performance.
Specific application scenarios for different types of IID
- UUID v4： scenes that apply to a sorting that is not required and that want ID to contain no information at all (e.g., creation time) and are often used for Token Generate, temporary file name, etc.
- UUID v7： The modern database design is the preferred. It follows the standard UUID format, with time sequencing and is well suited to act as MySQL, PostgreSQL primary key.
- ULID： ULID is the best option if you seek shorter ID length (26 bit characters) and a better URL-friendly. It uses Base32 encoding, which does not contain hyphens and is not case-sensitive, is well suited to be a public API resource identifier.
How can this online generator be used?
- Select type: Select v4, v7 or ULID according to your business needs. If you're not sure, UUID v7 Typically, the best common option for database development is the one.
- Settings format: Standard development is usually in the form of lowercase hyphens. If you need to use it for URLs or a specific system, you can select the " no hyphenation " mode.
- Batch generation: Enter the amount you want (maximum support 1000) ) Click the Generating button, and the system will provide you with a single identifier in a moment.
- Locally generated: For your data security, all the generating logic of this tool is executed locally in your browser, your ID Never send it to our server.
Common Question Answers (FAQ)
1. Will there be repetitions in UUID v7?
It's very difficult in theory. UUID v7 contains 48 mst timetamps and about 80 bit of random part. Even if it produces millions in the same milliseconds. ID, with a minimal probability of collision, is sufficient to meet the demand for most Internet-level applications.
Why is ULID only 26 places?
ULID is also 128 bit data, but it uses Base32 code (0-9, A-Z, excluding easily confused I, L, O, O, O, O, L, L, L, L, L, L, L, L, L, L, L, L, L, L, L, L, L, L, L, L, L, L, L, L, L, L, L, L, L, L, L, L, L, L, L, L, L, L, L, L, L, L, L, L, L, L, L, L, L, L, L, L, L, L, L, L, L, L, L, L, L, L, L, L, L, L, L, L, L, L, L, L, L, L, L, L, L, L, L, L, L, L, L, L, L, L, L, L, L, L, L, L, L, L, L, L, L, L, L, L, L, L, L, L, L, L, L, L, L, ) This is more efficient than the hexadecimal code used by UUID and therefore indicates the same amount of information in shorter string lengths.
3. What are the disadvantages of using UUID in a database?
UUID occupies more space (16 bytes vs 4/8 bytes) than it does from the integer. But by using time-series UUID v7, avoids the indexing bottlenecks caused by random UUID. Under modern storage hardware, UUID Flexibility (support for offline generation, easy to migrate) is often far above its space cost.