cloud pros and cons

performance and retrieving performance are conflicting.When you increase the index, the retrieval performance is improved, but the performance of the modification is reduced. When you reduce the index, you increase the performance of the modification and reduce the retrieval performance.Therefore, you should not create an index when the performance of the modification is far greater than the retrieval performance.How to create an index:1. Create index, such as name of CREATE INDEX 2, modify the

const, EQ_REF, ref, range, index, and all, means that all records in the data table must be read once, corresponding to each record in the previous data table- This situation can often be avoided by an index).The Possible_keys data column gives the various indexes that MySQL can use when searching for data records. The Key data column is the actual mysql-selected index, which is given in the Key_len data column for the length of the byte count. For example, for an index of an integer data colum

Using MySQL will of course have access to the MySQL storage engine, which you will see when creating a new database and creating a new data table.MySQL default storage engine is MyISAM, other commonly used is innodb.What kind of storage engine is better? This question is inconclusive and needs to be measured in terms of your needs and circumstances. Therefore, the concept of the two engines, principles, similarities and differences and their respective advantages and disadvantages have a detaile

(but is not foolproof or should be passed to the database for additional validation).Disadvantages:1. If you change the scope to make changes to the parameters of the input stored procedure, or if you want to change the data returned by it, you still need to update the code in the assembly to add parameters, update the GetValue () call, and so on, which is more tedious to estimate.2. Portability is poorBecause stored procedures bind applications to SQL Server, using stored procedures to encapsu

This article mainly introduces the JS merged array of several methods and pros and cons comparison, this article explains the concat, loop insertion, reduce and other methods combined arrays, and their pros and cons to do a comparison, the need for friends can refer to the nextThis article belongs to JavaScript's basic

I feel a lot of projects. Using Java or C's multithreaded library + thread-safe queue data structure can basically achieve the Goroutine+channel development can achieve the requirements, so why say Golang more suitable for the development of concurrent service side? What are the pros and cons of developing with Goroutine+channel and Java multithreaded +queue queues?What are the

, scalable.-Simple, weakly structured storage.-complex operations such as joins are weak.-Transaction support is weak.-Poor versatility.-Poor support for complex business scenarios without complete constraints.Although in the era of cloud computing, traditional database has a congenital disadvantage, but NoSQL database can not replace it, NoSQL can only be used as a supplement to the traditional data can not be replaced, so the disadvantage of avoidin

This article focuses on almost all methods for adding underline styles, and compares the pros and cons of each Approach. did not expect to have not noticed before the underline there are so many mystery! This article is translated by nzbin, Ailing Wind School draft. Without permission, no reprint! English source: css-tricks.com Posted Address: http://web.jobbole.com/89425/ There are m

IOS Miscellaneous Pen-19 (attributes and the pros and cons of variables) In the previous article I covered the differences between attributes and variables.This blog I will briefly explain the pros and cons of attributes and variables.Variable Advantages:Fast access speedDisadvantages:Not flexible to useProperty Disad

Description: The following references the contents of the sixth chapter of "Building a highly available Linux server" Fuqin.It is relatively simple to build a high-availability environment for load balancing, mainly to understand the principles. This article describes the pros and cons of three load balancers so that they can be used in real-world production applications by demand.At present, the online env

SSH project, what is the difference between using gethibernatetemplate and getsession? What are the pros and cons, thanks for the answer!Reward Points: 0-resolution Time: 2008-10-7 09:42SSH project, what is the difference between using gethibernatetemplate and getsession? What are the pros and cons, thanks for the answ

user manual 2.4 neo4j driver NEO4J provides a database driver for several languages, such as in Java, where you can insert a node: Driver Driver = Graphdatabase.driver ("Bolt://localhost", Authtokens.basic ("neo4j", "neo4j")); Session session = Driver.session (); Session.run ("CREATE (A:person {name: ' Arthur '})"); Session.close (); Driver.close (); Query node: Driver Driver = Graphdatabase.driver ("Bolt://localhost", Authtokens.basic ("neo4j", "neo4j")); Session session = Driver.session ()

of the Rocchio algorithm is that it is easy to implement, the calculation (training and classification) is very simple, it is usually used to measure the performance of the classification system of the benchmark system, and the practical classification system rarely use this algorithm to solve the specific classification problem.9 Comparison of various classification algorithmsAccording to the conclusions of this paper,Calibrated boosted trees has the best performance, random forest second, unc

Will there be such a feeling? It technology development knowledge is very broad and very deep, there will always be you do not understand the problem arises. One after another a new question, one after another a new challenge.Today, interpreting "inline pictures", what are inline images, and what are the pros and cons of using inline images? This is the question I interviewed a new startup company asked, an

lifetime of the content pointed to by the pointer (which may require the programmer to delete the requested memory at the appropriate time, but because of the efficient insertion/deletion of the pointer), the use of boost::any may avoid this situation, because we can store the type itself (of course, the pointer can be stored). This is one of the advantages of Boost::any.Boost::any Another advantage is that you can store any type. The previously mentioned mylist can only hold pointers to BaseCl

Task:Grilled all the pros and cons of all technologyJPA, this rotten thing.Http://www.blogjava.net/jobs/archive/2008/02/02/178917.htmlFirst, before we know what the benefits of LINQ to SQL are, it's important to understand why Microsoft has made such a thing first. What is the purpose of this thing:--of course, to meet programmers who do not know how to manipulate the data, not every programmer will manipul

Clear the pros and cons, use the inline inline syntax. Define the method in the class declaration; Inline methods are placed outside the class declaration, but must appear in the header file, and inline is used in the inline method declaration; Note: Inline is only a recommendation to the compiler, whether the inline decision is in the compiler;The cost of inline savings Function call Overhea

table from one or more tables, which is actually a query result, and the query that corresponds to the name and view of the view is stored in the data dictionary.(2). What are the pros and cons of views?A. Data security.Define different views for different users so that users can only see data about themselves. The database Authorization command enables each user to limit the retrieval of a database to a s

The pros and cons of blocking and non-blocking IO packages in Java the cornerstone behind the NIO design: The reactor pattern, the architecture pattern for event multiplexing and dispatch.Reactor (Reactor): Architecture pattern for event multiplexing and dispatch typically, the file or device specified for a file descriptor works in two ways: blocking and non-blocking. The so-called blocking means that when

The pros and cons of node. jsAdvantages:1. Use event-driven, asynchronous programming, designed for network services.2. Node. js non-blocking mode IO processing gives node. JS the ability to deliver high performance and outstanding load with relatively low resource consumption.3. Node. js is lightweight and efficient, and can be considered the perfect solution for data-intensive real-time applications.4. js