Reference · print-friendly

Client storage decision playbook

One page for design reviews. Walk top to bottom; stop when a row rejects the current candidate.

1. Gate A · Job (which store?)

2. Gate B · Shape (if IndexedDB)

• Database = name + one version per origin
• Object stores; keys: in-line / out-of-line / autoIncrement
• Indexes only for planned lookups — create in upgradeneeded
• Version bump = migration steps + multi-tab versionchange

3. Gate C · Runtime

• transaction(stores, mode) — prefer readonly
• put upserts; add create-once
• No unrelated await mid-transaction
• Modest results → get/getAll + range; large → cursor
• “Saved locally” ≈ transaction.oncomplete

4. Gate D · Ship risks

• Quota / eviction — not durable forever; re-hydrate path
• Private mode / clear site data
• Multi-tab writers + upgrade blocked UX
• Sync / conflict policy if multi-device or multi-tab edits
• Main-thread cost of large decode (workers if heavy)

5. Sentence template

“We use store family because job; schema stores/keys/indexes + version plan; runtime tx + query shape; we own one risk.”