← Evaluations/EVAL-20260402-142215
code
Apr 02, 2026CODE-023

Write a database migration that adds a NOT NULL column with a default value to a table with 50 million rows in PostgreSQL — without locking the table or causing downtime. Explain the step-by-step process, why naive ALTER TABLE fails at scale, and how to verify data integrity after migration.

Winner
GPT-5.4
openrouter
8.79
WINNER SCORE
matrix avg: 7.70
results.json report.mdFull dataset (CSV) →
10×10 Judgment Matrix · 84 judgments
OPEN DATA
Judge ↓ / Respondent →GPT-5.4Claude Opus 4.6Gemini 3.1 ProClaude Sonnet 4.6Grok 4.20DeepSeek V4GPT-OSS-120BGemini 3MiniMax M2.5MiMo-V2-Flash
GPT-5.44.54.35.87.5·5.87.7·6.3
Claude Opus 4.69.36.57.08.05.66.28.00.58.0
Gemini 3.1 Pro6.04.75.75.44.23.56.7·7.2
Claude Sonnet 4.69.08.66.38.87.38.08.6·8.3
Grok 4.208.88.46.68.76.68.68.08.66.0
DeepSeek V410.010.08.69.69.69.39.68.69.6
GPT-OSS-120B8.87.35.38.88.87.88.6·8.6
Gemini 39.69.67.810.09.67.59.2·9.6
MiniMax M2.58.67.65.87.89.08.07.38.68.1
MiMo-V2-Flash9.09.08.89.39.08.68.68.89.3