Databases · Senior · Question 26 of 75

How can you generate unique IDs across shards without a central sequence?

1Use the row count as an ID
✓Correct answer: Time-ordered unique IDs like UUID v7 or Snowflake-style IDs (timestamp + node ID + counter)
3Use SERIAL on each shard

Explanation

Per-shard sequences collide across shards. Time-ordered IDs stay roughly sortable and index-friendly.

Further reading

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