Open kagxin opened 4 years ago
返回有关查询计划的信息和查询计划的执行统计信息
每个阶段将其结果(即文档或索引键)传递给父节点。叶节点访问集合或索引。内部节点操纵由子节点产生的文档或索引键。根节点是MongoDB从中得出结果集的最后阶段。
COLLSCAN
IXSCAN
FETCH
SHARD_MERGE
SHARDING_FILTER
database.collection
胜出的计划的执行情况
ref: https://docs.mongodb.com/manual/reference/explain-results/index.html
MongoDB Explain Results
queryPlanner
stage
COLLSCAN
for a collection scan 集合扫描IXSCAN
for scanning index keys 索引扫描FETCH
for retrieving documents 根据索引去检索指定documentSHARD_MERGE
for merging results from shards 将各个分片返回数据进行mergeSHARDING_FILTER
for filtering out orphan documents from shards ???googlequeryPlanner信息,详细说明了查询优化器选择的计划
database.collection
executionStats
serverInfo
ref: https://docs.mongodb.com/manual/reference/explain-results/index.html