我已启用 BigQuery 预览功能基于历史的优化。我可以在 JOBS_BY_PROJECT 信息模式视图中看到一堆查询,其中包含以下详细信息:
{"optimizations":[{"parallelism_adjustment":"applied"}]}
问题是;如何以数字方式衡量此优化的影响及其好处?
根据文档,您可以通过基于历史的优化来查看应用了哪些作业
SELECT
job_id,
query_info.optimization_details
FROM `project_name.region-us`.INFORMATION_SCHEMA.JOBS_BY_PROJECT
WHERE job_id = 'sample_job'
LIMIT 1;
对于实际数字,我相信没有直接的方法来查看比较,但您可以在此处查询性能以获得洞察力和
平均插槽利用率:
SELECT
SUM(total_slot_ms) / (1000 * 60 * 60 * 24 * 7) AS avg_slots
FROM
`region-us`.INFORMATION_SCHEMA.JOBS
WHERE
-- Filter by the partition column first to limit the amount of data scanned.
-- Eight days allows for jobs created before the 7 day end_time filter.
creation_time BETWEEN TIMESTAMP_SUB(CURRENT_TIMESTAMP(), INTERVAL 8 DAY) AND CURRENT_TIMESTAMP()
AND job_type = 'QUERY'
AND statement_type != 'SCRIPT'
AND end_time BETWEEN TIMESTAMP_SUB(CURRENT_TIMESTAMP(), INTERVAL 7 DAY) AND CURRENT_TIMESTAMP();