Web29 jan. 2024 · MongoDB 에서는 Plan Cache 를 Clearing 을 하기 위해 2가지 method 를 제공한다. "clear ()" 를 하게 되면 Plan Cache 에 저장된 모든 Query Shape 의 Plan 을 삭제한다. 하지만 일부의 쿼리만 비효율적으로 caching 되어있을 수도 있기때문에, 특정 Query Shape 만 Clearing 할 수도 있다. 이를 위한 method 가 "clearPlansByQuery ()" 이다. ** … Web16 mei 2024 · 那是不是因为这个索引是后来加的，plan-cache还没有更新的。清理掉执行计划缓存，执行操作. db. historyRecord. getPlanCache (). clear 继续观察，发现并没有什么用。百思不得其解，在深入解析 MongoDB Plan Cache找到一些思路，MongoDB的执行计划. 其中扫描N次中N是10倍的执行 ...

Query Plans — MongoDB Manual

Web28 sep. 2024 · MongoDB Optimizer在评估时会touch数据，获得一个运行时信息再去结合估算，进行Plan的打分，得分最高的就是最优的。 Optimizer分为logical逻辑优化和physical物理优化，逻辑优化在上面CanonicalQuery时已经做了，这里只涉及物理优化。 Optimizer会把所有的Plan都执行一小部分数据，在执行终会统计扫描次数、获得结果次数等stats指 … WebThe PlanCache methods are only accessible from a collection's plan cache object. To retrieve the plan cache object, use the db.collection.getPlanCache () method. Note. For … night relaxing medication

MongoDB

WebThis will have some impact (I'll explain in a moment) but is better than clearing out your whole cache. EXEC sp_recompile Table; When you clear out your query plan cache, or mark a stored procedure for recompile the optimizer has to re-create the plan for that piece of code. This of course takes time. WebStarting in MongoDB 4.2, you can use the $planCacheStats aggregation stage to view plan cache information for a collection. Plan Cache Flushes The query plan cache does not … Web31 mrt. 2024 · Line 22— Override the exec function to add our caching logic. Line 23 — Check if the query should use cache. Line 27 — Create a unique key for the cache, which is the query itself and collection name. The Redis key has to be a string so we convert it using JSON.stringify. Line 33— Try to retrieve the data from cache and store in cacheValue. nsaa hs football scores