what is mackeeper and is safe

not this I do not know, just the majority of the default page, are index.html)7) Http://mail.163.com/index.html: This is called URL, Uniform Resource Locator, global address, used to locate resources on the Internet. Perhaps by this time, you still do not understand, this domain name and site name What is the difference?OK, small to tell you!For example, you b

More and more friends asked in QQ or QQ groups, "What Do website art engineers need?" and "How do they learn webpage art "...... Or you may be new to this course. I don't want to answer the same question again. I wrote this article to talk about what a webpage artist is and what a webpage artist

In the C language, for definitions and declarations, perhaps we are very familiar with, but not necessarily really understand!Definition means: The definition is to create a (compiler) an object, to allocate a memory space for this object and name, that is, the name of the variable or object that we normally call, once this is a memory space match, then in the de

1 in-progress validation of the document 2 determines the rendering mode of the browserStandard mode is strict,Weird patterns and promiscuous patterns are not allowed, old, wrongBusiness hooks with progressive enhancements elegant downgradeIncremental increase is mainly for the bottom version of the browser for page construction, to ensure basic execution. Interactive and improved for high-version browsers,

The so-called generation of documents is to copy the relevant directory table of the file to the area specified in main memory, the establishment of a file control block, that is, the establishment of the user and the file connection.The so-called closed file is the user declared that the file is no longer in use, the

Label:What is the maximum length of int (11), and what is the maximum length of varchar in MySQL? 　　What is the maximum length of int (11)? In the SQL statement, int represents the type of field you want to create, int represents an integer, and 11 represents the length of t

1. What is a pattern? Patterns, that is, pattern. In fact, is to solve a certain type of problem methodology. You have summed up the method of solving some kind of problem to the theoretical height, that is the pattern. The classic definition given by Alexander

what circumstances are indexes, but not used?Indexes do not always take effect, such as the following, which will invalidate the index : If there is or in the condition, even if some of the conditions in the index are not used ( which is why the use of or is minimized ), in the example user_id no index

Traditional website construction can be said that the internet has just arisen when the product, has been synonymous with the past, now if there are enterprises to choose this kind of traditional construction station services, can only say that business leaders on the internet this piece of attention, or no internet thinking consciousness, even say no sense of crisis, there are sites and no site relationship is not big, Indifferent attitude. Some busi

What is LinuxThe same set of operating systems cannot be run on a platform of different architectures.Refer to the HARDWARE function function and modify your operating system program code, the revised operating system will be able to run on another hardware platform. This is the software migration .Linux is an open-sou

What this article brings to you is about what is BFC? What is the use of BFC in CSS? , there is a certain reference value, the need for friends can refer to, I hope you have some help.

prevent inconsistent data. Database at design time, the primary key plays a very important role.The primary key guarantees that the record is unique and the primary key domain is not empty, and the database management system automatically generates a unique index for the primary key, so the primary key is also a special index.2. There can be multiple unique inde

There is no doubt that the Linux kernel needs to manage all the hardware devices connected to the computer. If you want to manage these devices, you need to communicate with them first, there are generally two scenarios for this functionality:1. Polling (polling) allows the kernel to periodically query the status of the device, and then make the corresponding processing;2. Interrupt (interrupt) allows the hardware to signal to the kernel when needed (

What is a data warehouse, and what is the difference between a databaseDataWarehouseis a subject-oriented (Subject oriented), integrated (integrate), A relatively stable (non-volatile), data collection that reflects historical changes (timeVariant) to support management decisions. (1) topic-oriented: Index data in the

the flexibility of transaction management,DmProvides a set save point (SavePoint) statement and rollback to the Save point languageSentenceSave points provide a flexible rollback,Transactions can be rolled back to a savepoint during execution.Before the Save pointOperation is valid, and subsequent operations are rolled back.DmAlso have the above4Properties: atomicity, consistency, isolation, and persistence.2.Inconsistencies in concurrency and dataIf