Every ORDER BY id query on the messages table sorted or scanned the
whole session: get_messages_around's window seek, latest_message_row_id
(LIMIT 1), and get_messages' full-load ordering all paid O(session
history) per call — hot mid-turn via session_search and reactions.
messages.id is an original column (INTEGER PRIMARY KEY AUTOINCREMENT),
so the index lives in SCHEMA_SQL next to idx_messages_session — no
legacy-column migration hazard (the kanban lesson from #28776 does not
apply).
Measured (real schema, one 20k-message session, median of 30):
get_messages_around 7.08 -> 0.22 ms (32x), latest_message_row_id
3.37 -> 0.011 ms (307x), get_messages full load 111.6 -> 98.6 ms
(1.13x — remaining cost is row deserialization, not the sort).
Window results byte-identical at probe points across the session.
Tests: VM-step pin (get_messages_around bounded work, calibrated
~12 vs ~855 handler calls, threshold 300 — fails without the index)
and window parity with/without the index. No EXPLAIN/plan text
(behavior contracts, AGENTS.md).
Translates the full English docs corpus (335 files) into Simplified
Chinese under website/i18n/zh-Hans/. Combined with PR #31895 (cross-
locale link fix), the 简体中文 locale toggle now serves a complete
Chinese site with working cross-page navigation.
Pipeline:
- Claude Sonnet 4.6 via OpenRouter, 8-way concurrent
- Preserves frontmatter keys, code blocks, MDX/JSX, link URLs, brand
names, and technical jargon (prompt/token/hook/MCP/ACP/etc.)
- Translates only frontmatter title/description and prose
- Two largest files (configuration.md 93KB, research-paper-writing.md
107KB) retried with 64K max_tokens after initial fence-drift
- 3 manual post-fixes for MDX edge cases the model didn't escape:
< in optional-skills-catalog table, double-quotes in an alt= tag,
and a bare URL adjacent to a full-width period
Cost: ~$30 total (Sonnet 4.6 input $3/M + output $15/M).
Verified `npm run build` succeeds for both en and zh-Hans locales,
no double-prefixed /docs/zh-Hans/docs/ URLs in rendered output,
all in-page navigation resolves correctly.
Translations are machine-generated and may need human review on
specific pages — but they're an enormous improvement over the
previous state (3 zh-Hans pages out of 335).
spfcraze
Teknium