byod guidelines

MySQL study Notes-guidelines for selecting indexes based on 17th optimization I. The index column to be searched is not necessarily the column to be selected In other words, the column most suitable for indexing is the column that appears in the WHERE clause or the column specified in the join clause, rather than the column in the selection list after the SELECT keyword, for example: SELECTCol_a distinct is not suitable for indexing columnsFROMTbl1 l

This article mainly introduces some suggestions and guidelines on the design of JavaScriptAPI. it lists many well-known jsapis for auxiliary instructions and strongly recommends them! It is a common concept for a friend who needs to refer to the design. generally, it can be understood as a plan or framework for a specific part to be prepared. In the Oxford English Dictionary, design is a main thread that binds art, system, hardware, or more. Software

SQL optimization tips and guidelines To optimize queries and avoid full table scanning, you should first consider creating an index on the columns involved in where and order. Try to avoid null value determination on the field in the where clause. Otherwise, the engine will discard the index and perform full table scan. select id from t where num is null It is best NOT to leave NULL for the database and try to use not null to fill the database. Remark

Atitit. after upgrading the class library framework API Code Compatibility Design Guide1. increase The API directly, the version number is added 1 above the comment 2. Discard APIs, use your ideas @dep13. Modify the API,14. Modify dependent import, ya Yao Add file mode. Maintain compatibility. 15. preferred to select the same file in the changes, because the file more than a bad management, the compilation speed is also slow ... 15.1. Advantages and disadvantages of adding file patterns

rendering (poor user experience), blocking onload event, using XHR Eval, XHR injection does not trigger the browser's busy indicator, whether the busy indicator is triggered by the technology and browser together. The purpose of the browser busy indicator is to let the user know that the page is running.If the download script is parallel, the browser execution script is the first to arrive at the first execution. is not performed in the order of arrangement, except document.write script Tag, sc

over the mouse.P:hover{background-color:gray;}2.: Focus Pseudo-classWhen an element declares a focus pseudo-class, the corresponding CSS rule is applied when it gets the focus.3.: Target Pseudo classIf a user clicks on a link to another element in the page, that element is the target, which can be selected using the target pseudo-class.Two. Structured pseudo-Class1.: First-child and: Last-child: First-child represents the first element in a group of sibling elements, whereas: Last-child represe

its content, and it needs to be explicitly set width:100% to remain the same width as the browser. At the same time floating section,footer will try to push up to the floating element next to the need to set the clear property of footer, the cleared element will not be promoted to the floating element next.Method Three: Add non-floating purge elementsThe third method of forcing a parent element to contain its floating child elements is to add a non-floating child element to the parent element a

block element, it will scale to the size of its content, and it needs to be explicitly set width:100% to remain the same width as the browser. At the same time floating section,footer will try to push up to the floating element next to the need to set the clear property of footer, the cleared element will not be promoted to the floating element next.Method Three: Add non-floating purge elementsThe third method of forcing a parent element to contain its floating child elements is to add a non-fl

gameobject and components Wake-up Gameobject and components Whether it's cloning or reading from memory, the last three takes time, but the read time increases linearly as the level increases.Now on the platform, it is faster to store the device from memory or not. In the future, as storage media changes,can also be very different, desktop PC will be mobile devices to fast. If you are loading from a slow device. The time to read the data is much more than the instantiation time, so the

. 9png Production Tutorials2. Android Dimension design Daquan and Android transduction specification3, app design and cutting basic knowledge points and precautions4, Android interface design Novice tutorial and Android design experience sharing5, Android app Novice Design tutorial: 19 Android Design Experience Daquan4, Android app design specifications of the adaptation and design plan test preview(1) Dimensioning tool Markman (Mark Eel)(2) App quick Cut Chart tool: Cutterman(3) A visual Androi

PreviewThe 15th chapter: Music16th Chapter: VoiceOver17th Chapter: Path18th Chapter: Edit menuChapter 19th: Revocation and re-doing20th chapter: Keyboard and input viewsPart IV: UI elementsChapter One: Strip elementsChapter II: Content ViewChapter III: ControlsFourth: Temporary viewPart V: Icons and graphic designChapter One: icons and picture sizesChapter Two: App iconChapter Three: Loading picturesFourth chapter: Bar button iconThe fifth chapter: Newsstand icon (newsstand is literal translati

background and appearance, separating the contents of it from the rest of the screen.Reminders, as shown below, places a list on different layers. When a user operates on one of these lists, the other lists are collected to be placed at the bottom of the screen.When users move (switch) between years, months, and days, the calendar uses a strengthened transition to give them a sense of system and hierarchy. In the scrolling year view shown below, the user can doll see today's date and perform ot

(floattemperature) {heateralarmer.temperaturcurrent=temperature; } Public Override stringToString () {return$"{this.company},{this. Trademark},{heateralarmer.temperaturcurrent}/{heateralarmer.temperaturalarm}"; } } /*Hisense, Wedding night, 0/95overflow: Hisense, wedding night, 88/80 Hisense, wedding night, 88/80 Hisense, wedding night, 95/95 Hisense, wedding night, 95/95 Hisense, wedding night, 90/95*/ Public classRunmyapp {Static voidMain (string[] args) {Waterheater Hisense

(_SS,">ph") Print (NE,value, value2)--Call result AASD, China - Packaging Variable Type definitions #define OP_zstring' Z ' //empty string #define OP_bstring' P ' //string with length less than 2^8 #define OP_wstring' P ' //string with length less than 2^16 #define OP_sstring' A ' //String length less than 2^32/64 * / #define OP_string' A ' //Specify length string #define OP_float' F ' / * FLOAT * / #define OP_double' d ' / * double * / #def

developers should go frequently, click on the tutorials above or direct access to the address Https://developer.marklogic.com/learnThis is marklogic specifically for developers to learn the site, a lot of tutorials more detailed explanation of marklogic, the video link of the web is YouTube, need a certain technical means to access.Documents are organized by directory, easy to access, the introduction of the knowledge point is relatively thin, suitable for targeted learning, a lot of content is

When we write the program, the most used is the processing of the string, and the conversion between ANSI and Unicode often make us dizzy eye disorder.It should be said that Unicode is a good way to encode, in our program should try to use Unicode encoding, when we write programs, it is best to follow the following guidelines:Basic guidelines:1. Imagine a text string as a character array, not a char or byte array2. Start using common data types to rep

, we need to choose to rebuild the index to solve the problem completely.Summarize index usage principles:1: Do not index the data volume of the table, for the small table, the cost of table scanning is not very high.2: Do not set too many indexes, in a table without a clustered index, the maximum can be set 249 nonclustered indexes, too many indexes will first bring more disk space, and when the data changes, the maintenance of the index is particularly performance-consuming.3: Rational applica

Log considerations Large-scale index operations, performed offline or online, can generate Large data loads that can cause the transaction lo g to quickly fill. To make sure that the index operation can is rolled back and the transaction log cannot be truncated until the index Operatio n has been completed; However, the log can backed up during the index operation. Therefore, the transaction log must has sufficient space to store both the index operation transactions and any Concurren T user tr

1 Avoid Mixed Clock edgesguideline　　Avoid using both Positive-edge and Negative-edge triggered flip-flops.If must use both Positive-edge and Negative-edge triggered flip-flops, then1) Model The worst-case duty cycle of the clock accurately in synthesis and timing annalysis2) document the assumed duty cycle in the user documentation.guideline If must use a large number of both Positive-edge and Negtive-edge triggered FFs,Separate them into different modules.Bad example-mixed clock edges　　Better E

--Excerpt from "Linux/unix Design Idea"(0) Allow the user to customize the environment.(1) Try to make the operating system kernel small and lightweight.(2) Use lowercase letters and try to keep them short.(3) protect the trees.(4) Silence is gold.(5) Thinking in parallel.(6) The sum of the parts is greater than the whole.(7) Looking for a solution for 90%.(8) worse is better.(9) The level of thinking.This article is from the "P6xos" blog, make sure to keep this source http://p6xos.blog.51cto.co