(6) index:the index tree is scanned, MySQL can use this type when the query uses only columns that are part of a single index. 表示全索引扫描(full index scan), 和ALL类型类似, 只不过ALL类型是全表扫描, 而index类型则仅仅扫描所有的索引, 而不扫描
As so-called big data--various types of information gathered on a massive scale, such as smartphone locations--becomes widely used, controversy has arisen over how telecom operators should obtain the consent of individuals whose private information may be offered to a third party without their ...
(4) ref: It is used if the join uses only a leftmost prefix of the key or if the key is not a PRIMARY KEY or UNIQUE index (in other words, if the join cannot select a single row based on the key value). 相比eq_ref,不使用唯一索引,而是使用普通索引或者唯一性索引的最左前缀,可能会...
I use unsigned long long datatype occasionally, in order to reduce typos l would create a typedef for the same. typedef unsigned long long bigint; Now it would be more effective and easy to use the short typename instead of lengthy one. bigint num1; is more elegant statement than unsi...
“And if you use a computer to draw a picture of a puppy, GenAI could help you draw a really good picture. With GenAI, you can ask the computer to create a picture of a purple puppy wearing clown shoes that can fly in the air with its big ears. And just like magic, the computer...
The key to every BIM Manual is keep your manual flexible enough to be universally applicable to all the types of project in which your office is involved. Posted on February 13, 2019 BIM Manager Superstar A few months ago Ideate came to me and asked if I would give a presentation on how...
The implementation of this API operation differs based on types of operators. This API operation is called for multiple times until data of all downstream operators is pulled. The value of this parameter indicates the execution duration in the next phase and is in the format of maximum duration...
They're the atomic equivalents of wobbly old buildings: sooner or later, they're bound to fall apart, splitting into bits like a large building tumbling to the ground and releasing energy on the way. When large atoms split into one or more smaller atoms, giving off other particles and ...
That younger individuals perceive the world as moving slower than adults is a familiar phenomenon. Yet, it remains an open question why that is. Using event segmentation theory, electroencephalogram (EEG) beamforming and nonlinear causal relationship est
The data type defines which operations can safely be performed to create, transform and use the variable in another computation. There are two types of data types in Java: Primitive data types: The primitive data types include boolean, char, byte, short, int, long, float and double. ...