chromebook advantages and disadvantages

Label:In general, the index will speed up the query, but will affect the insertion, modification, deletion of data, and occupy the physical space;So we should create the index reasonably, and we should create the aggregate index first, and then create the non-aggregated index.To create an index on a column that is frequently queried, and avoid too many indexes if the table columns are small;Advantages Detailed Description:Creating an index can greatly

the form of a two-dimensional table! a two-dimensional table is made up of rows and columns, knowing that the row and column numbers will be able to locate the data in the table! Excel is a two-dimensional table! Easy to use, the basic common SQL language makes it easy to operate relational databases! SQL is supported , so complex queries can be made! easy to maintain, rich integrity (domain integrity, entity integrity, referential integrity, and custom integrity) greatly reduces data redun

created, it waits for the first time to execute. At that time, the stored procedure was optimized, and the query plan was compiled and cached on the system. When you run the stored procedure several times, the cached query plan is used instead of creating a new query plan, unless specified by using the WITH RECOMPILE option. This means that each time the stored procedure is used, the stored procedure skips a lot of optimizations and compilation work. The exact time to save depends on the comple

complexity of the application index-ready file is O (n).C) Poll use Nfds to specify the maximum number of file descriptors and events to listen to, this number can reach the system agreed to open the largest file description of the descriptor. That is, 65535.D) can only work in the LT mode.3) Epoll:A) epoll the file Description descriptor and events of the user's booklet into the event table in the kernel. Provides a stand-alone system call Epoll_ctl to manage user events, and epoll the way cal

Label:The benefits of a relational database:1. Maintain data consistency (transaction processing)2. Due to standardization, the cost of updating data is small (the same fields are basically only one place)3. Complex queries such as joins can be madeOne of the best advantages of relational databases is the ability to maintain data consistency.The lack of a relational database:Not good at handling1. Write processing of large amounts of data2. Index or t

1. star topology A star topology is composed of a central node and a site connected to a central node through a point-to-point communication link. The star topology has the following advantages: (1) simple control. (2) Easy Fault Diagnosis and isolation. (3) convenient services. Disadvantages of the star topology: (1) Considerable cable length and installation workload. (2) the burden on the central node is

Now many of our friends will store the session in the cookie when performing website security verification, so that we can encrypt some data, so what are their advantages and disadvantages and those security problems? Next, let's make a comparison. Now many of our friends will store the session in the cookie when performing website security verification, so that we can encrypt some data, so what are their

Disadvantages: the disadvantage of java is that it is too heavy, the learning curve is too steep, the performance is really not high, there are too few Chinese materials, mainly in French, followed by English. In addition, due to the early year, the syntax is relatively old (that is why laravel is good, new year, and many new technologies are used ). The advantage is that there are enough ready-made components, which are massive and open-source, and

Discussion on advantages and disadvantages of Cordova and environment deploymentSuhuajieBrief introductionCordova is a fast-developing platform for creating cross-platform mobile applications using HTML, CSS, and JavaScript. It enables developers to take advantage of the core features of smartphones such as the iphone, Android, Palm, Symbian, WP7, Bada, and BlackBerry-including geolocation, accelerators, co

This article describes the advantages and disadvantages of three Linux Server monitoring technologies, including SNMP proxy (client), SSH, and private proxy (client) installation. The powerful functions and beautiful interfaces of linux make many enterprises use linux as servers. The following describes the advantages and dis