Why AI-Generated SQL Fails at Structural Verification

LLMs are probabilistic models.
They predict likely JOIN paths based on naming and pattern similarity.

But data relationships are deterministic structures.

When foreign keys are missing, models rely on:

· Naming similarity

· Cardinality assumptions

· Common key patterns

The problem?

Plausible JOINs are not verified JOINs.

Structural correctness requires analyzing:

· Distinct value overlap

· Inclusion patterns

· Null distribution

· Domain compatibility

Without structural validation, AI-generated SQL becomes confident guessing.