Rubyflow iconRubyflowAug 30, 2026

The Race Your Rails Validation Cannot Prevent

A source-backed explanation of why two Rails uniqueness validations can pass concurrently, how a composite unique index arbitrates the inserts, and how Active Record exposes the losing write.

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A source-backed explanation of why two Rails uniqueness validations can pass concurrently, how a composite unique index arbitrates the inserts, and how Active Record exposes the losing write.

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A source-backed explanation of why two Rails uniqueness validations can pass concurrently, how a composite unique index arbitrates the inserts, and how Active Record exposes the losing write.

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