Querying

Status: shipped.

query = client.query("""
    SELECT user_id, SUM(amount) AS total
    FROM sales.orders
    WHERE placed_at > TIMESTAMP('2024-01-01')
    GROUP BY user_id
    ORDER BY total DESC
    LIMIT 10
""")
for row in query.result():
    print(row.user_id, row.total)

Supported SQL features track the compatibility matrix. SQL-function mapping is documented in sql-function-mapping.md.

Caching

Identical queries return cached results within the configured TTL (BQEMU_QUERY_CACHE_TTL_SECONDS, default 24h). The cache is invalidated automatically when base tables change (via TableDataChanged events).

Set use_query_cache=False on the job configuration to bypass.

Dry-run

job_config = bigquery.QueryJobConfig(dry_run=True, use_query_cache=False)
job = client.query(sql, job_config=job_config)
print(job.total_bytes_processed)

Dry runs perform full SQL validation but do not execute; the byte estimate is derived from catalog num_bytes statistics for referenced tables.