EXPLAIN works with SELECT, DELETE, INSERT, REPLACE, and UPDATE statements. EXPLAIN与SELECT、DELETE、INSERT、REPLACE和UPDATE语句一起工作。 When EXPLAIN is used with an explainable statement, MySQL displays information from the optimizer about the statement execution plan. That is, MySQL explains how it...
MySQL explains howit would process the statement, including information about how tables are joinedand in which order. EXPLAIN EXTENDED can be used to provide additionalinformation.
4.4).cursor.allowDiskUse()allows MongoDB to use temporary files on disk to store data exceeding the 100 megabyte system memory limit while processing a blocking sort operation. If the explain plan does not contain an explicitSORTstage, then MongoDB can use an index to obtain the sort order....
To use the information that the openCypher explain feature provides, you need to understand some details about how the DFE query engine works (DFE being the engine that Neptune uses to process openCypher queries). The DFE engine translates every query into a pipeline of operators. Starting fro...
Explain how programmed I/O is different from interrupt driven I/O. What is polling? In C++, describe an iterative version of mergeSort. Explain a buffer overflow. How does input output work? Explain 1's complement and 2's complement of a binary number. Explain briefly with example. ...
Using sort_union(...), Using union(...), Using intersect(...) (JSON property: message) These indicate the particular algorithm showing how index scans are merged for the index_merge join type. See Section 8.2.1.3, “Index Merge Optimization”. Using temporary (JSON property: using_temp...
How does Docker work? The diagram below shows the architecture of Docker and how it works when we run “docker build”, “docker pull” and “docker run”. There are 3 components in Docker architecture: Docker client The docker client talks to the Docker daemon. ...
accurate body control a logistical nightmare. There's nothing easier than lifting your hand to scratch your nose—your brain makes it seem to easy—but if we try to replicate this sort of behavior in a machine, we instantly realize how difficult it is. That's one reason why, until relativ...
How binoculars use lensesThe way light bends when it goes from air to a different material (such as water or glass) is called refraction. (For a full explanation of how it works, please see our detailed article on light.) Refraction is the key to how lenses work—and lenses are the ...
Using sort_union(...), Using union(...), Using intersect(...) (JSON property: message) These indicate the particular algorithm showing how index scans are merged for the index_merge join type. See Section 10.2.1.3, “Index Merge Optimization”. Using temporary (JSON property: using_tem...