## Problem
Moving the Logs Explorer to ClickHouse means users' saved BigQuery
queries no longer run.
<img width="2430" height="1010" alt="CleanShot 2026-06-29 at 11 36
04@2x"
src="https://github.com/user-attachments/assets/ae0ab155-7d3d-4ae9-81c3-22bf3a88cf8c"
/>
## Fix
Rewrite the query with AI instead of a SQL transpiler. AI handles the
long tail of nested fields and dialect differences far better than a
rule-based rewriter, and it needs no extra runtime dependency.
- `rewriteLogsSqlWithAI` posts the current query to
`/api/ai/code/complete` with `dialect: 'clickhouse'`. The endpoint skips
the Postgres schema and best-practices for that dialect and uses
logs-specific instructions and model so the output is ClickHouse logs
SQL (FROM `logs` + `source` filter, no `unnest` joins, nested fields
read from `log_attributes['...']`).
- The query's `source` is detected and its real `log_attributes` keys
are fetched and passed to the model, so it maps to exact paths instead
of guessing.
- The rewrite runs in the background and is proposed as a side-by-side
accept/discard diff in the editor. The AI Assistant panel is not opened.
- Entry points: a banner shown only for legacy-looking queries
(dismissal persisted), and a "Fix Query" button next to Field Reference.
- The Field Reference drawers discover `log_attributes` keys from real
data so the listed fields match what the source actually emits.
## Dependencies
Built on top of #47265 (Logs Explorer -> OTEL endpoint) — that is the
base branch of this PR. Merge #47265 first. Behind `otelLegacyLogs` (off
by default).
Part of DEBUG-145 (split from #47087).
## How to test
- Open the Logs Explorer with a BigQuery logs query (the templates have
some), click "Fix Query", and confirm the diff shows valid ClickHouse
SQL. Accept it and confirm the applied query runs.
<!-- This is an auto-generated comment: release notes by coderabbit.ai
-->
## Summary by CodeRabbit
* **New Features**
* Added an OTEL legacy logs workflow (behind a feature flag) with an
interactive banner and a “Fix Query” ClickHouse rewrite action,
including an accept/discard diff review overlay.
* Introduced OTEL-aware field reference rendering with dynamic discovery
of `log_attributes` keys and updated OTEL source insertion behavior.
* Enabled dialect-aware SQL completion for ClickHouse logs, using
logs-specific instructions and output constraints.
* **Bug Fixes**
* Improved rewrite flow validation and handling, including log source
detection and cleanup of AI-generated SQL formatting.
* **Tests**
* Added Vitest coverage for rewrite prompt generation,
detection/classification utilities, SQL fence stripping, OTEL field
mapping, and OTEL log attribute key discovery.
<!-- end of auto-generated comment: release notes by coderabbit.ai -->
---------
Co-authored-by: Claude Opus 4.8 (1M context) <noreply@anthropic.com>
Co-authored-by: Joshen Lim <joshenlimek@gmail.com>
