What 'Project Hail Mary' teaches us about the PlanetScale vs. Neon debate

PlanetScale vs. Neon: Use Cases and Trade-offs

• Both are framed as good but different tools, optimized for distinct workloads rather than direct substitutes.
• Rough heuristic from the thread:
  • PlanetScale: better fit for predictable, steady load where you provision fixed CPU/RAM and accept idle capacity.
  • Neon: better fit for spiky/variable workloads; you pay for compute hours and get autoscaling and scale-to-zero.
• One commenter points out a caveat: Neon’s “active time” billing keeps compute on for ~300 seconds after each request, so a steady trickle of traffic incurs 24/7 billing anyway.

Compute–Storage Separation vs. Single-Box Latency

• A database reliability engineer argues strongly against separating compute and storage (e.g., Aurora-style):
  • Writes must traverse the network and be replicated across multiple storage nodes/AZs, adding ~1ms+ each time, which is large vs. local SSD.
  • Aurora MySQL loses MySQL’s change buffer optimization, forcing synchronous secondary index updates and worsening write latency.
  • Combined with common app‑side issues (JSON-everywhere, poor normalization, bad queries), this can lead to “disastrous” performance.
• They praise some Aurora features (survivable page cache, low replication lag) but downplay the value of autoscaling for predictable peaks.
• Another commenter suggests the latency hit is accepted mainly to gain scalability, durability, and flexibility.

RDS vs. Newer Managed Offerings

• One user running multi‑TB Postgres on RDS 24/7 says it “seems fine” and asks why switch.
• Reply: RDS works, but AWS pricing is seen as increasingly “greedy”; PlanetScale/Neon may cut costs and improve DX, especially now that PlanetScale offers Postgres.

Branching, Dev Experience, and Security

• Neon’s instant branching is highly praised: easy to give every dev or feature branch its own DB snapshot with minimal disk overhead.
• Concerns raised about prod data in non‑prod branches; suggested mitigations: anonymized base dumps, though many security teams disallow prod data outside prod regardless.

AI, “Vibe Coding,” and Safety

• Some criticism of Neon’s AI/vibe‑coding marketing: catching AI‑generated SQL injection after the fact is seen as a poor substitute for understanding security fundamentals.

Book Tangent: Project Hail Mary

• Large side thread debates the book’s merits:
  • Consensus: fun, fast, very readable “cheeseburger sci‑fi,” strong on problem‑solving and “competence porn,” weak on deep characters or literary quality.
  • Audiobook receives especially strong praise; many say it’s better experienced in audio due to performance and sound design.
  • Compared repeatedly to The Martian: similar structure and feel; some prefer The Martian, others Project Hail Mary.
  • Divided views on whether audiobooks “count” as reading; one commenter insists they’re a different medium, others reject that as snobbish.
• Numerous alternative sci‑fi recommendations appear (e.g., Children of Time, Dune, Neuromancer, Hyperion, Culture series, Ted Chiang collections), generally framed as “meatier” than Weir’s work.