I have recorded my questions during the PHP interview.

Introduction: This is a PHP interview I have encountered. Here I will record the details page, introducing PHP, related knowledge, skills, experience, and some PHP source code.

Class = 'pingjiaf' frameborder = '0' src = 'HTTP: // biancheng.dnbc?info/pingjia.php? Id = 337763 'rolling = 'no'>

Continuous updates. If you have good questions and want to share them or have better explanations or methods, please leave your footprints y (^_^) y

CodeOptimization

For ($ I = 0; $ I <8; $ I ++ ){
Array_push ($ week, $ ARR );
}

For ($ I = 0; $ I <8; $ I ++) {$ week [] = $ arr [$ I];} // This eliminates the extra burden of calling a function.

Benefits and disadvantages of Indexing

Answer

Benefit: When querying, the system first locates the number of rows of a specific value in the index list, greatly reducing the number of rows that match the traversal.
Disadvantage: No matter how you query this table, it does not make sense to increase the index because there are a large number of duplicate values in the field.
If there are few records, increasing the index will not lead to speed optimization, but will waste storage space, because the index requires storage space, in addition, each execution of update, insert, or delete requires re-calculation of the index of the field.
RelatedArticleAddress: http://xdeduzb.blog.163.com/blog/static/81993637201111044846169/

Zz

Love J2EE follow Java Michael Jackson video station JSON online tools

Http://biancheng.dnbcw.info/php/337763.html pageno: 9.