Address code-reviewer findings on the bigquery_query() rewrite path:
1. Outer LIMIT wrap — bigquery_query() materialises BQ result into DuckDB
before fetchmany sees it (vs ATTACH-catalog Storage Read API streaming).
A user 'SELECT *' against a billion-row remote table would buffer the
entire result before request.limit applied. Wrap rewritten SQL in an
outer 'LIMIT N+1' so the cap pushes into the BQ job itself.
2. Dollar-quoted inner SQL — naive replace("'", "''") doubling missed
DuckDB backslash-escape sequences (\\, \\n, \\t, …). A predicate
like 'WHERE name = ''O\\'Brien''' was unsafe under the doubling
path. DuckDB $bqq_inner$ … $bqq_inner$ form takes the inner SQL
verbatim with no escapes whatsoever. Falls back to legacy doubling
if user SQL improbably contains the literal tag.
3. Parse-error fallback — when the rewritten path fails with a BQ-side
parse / validation error (DuckDB-only syntax like ::INT cast that
survives identifier rewrite but BQ refuses), retry the user's
original SQL via the legacy ATTACH-catalog path so the request still
succeeds. Mirrors the existing dry-run fallback contract.
4. CHANGELOG — delete duplicate CLI bullets that landed under
already-released [0.38.1] (file corruption from merge — entries are
correctly under [0.39.0]).
User SQL hitting query_mode='remote' BigQuery rows was 50-100x slower
than the equivalent direct bigquery_query() call because DuckDB's master
view (CREATE VIEW … AS SELECT * FROM bigquery.<ds>.<tbl>) does not push
WHERE/SELECT/LIMIT into BQ in ATTACH-catalog mode. The BQ extension opens
a Storage Read API session over the entire upstream table; on >100M-row
sources this was 70-150s and frequently failed with 'Response too large
to return'.
Extract the existing dry-run rewriter's core (table-name → BQ-native
backtick path) into a shared helper. Add an execution-path rewriter
that wraps the whole user SQL in bigquery_query('<project>', '<inner>')
so the BQ planner sees the full query and engages partition pruning +
projection pushdown server-side.
Conservative fall-through: cross-source JOINs (BQ ↔ Keboola/Jira local),
queries already containing bigquery_query(, and unconfigured BQ project
all skip the rewrite and run the original SQL via ATTACH-catalog so
behavior degrades gracefully.
