how much 1000 rand

The RAND () Optimization Method for MySQL optimization and the rand Method for mysql Optimization As we all know, in MySQL, if order by rand () is used directly, the efficiency is very poor because it will be executed multiple times. In fact, this

As we all know, in MySQL, if direct order by RAND (), the efficiency is very poor, because it will be executed multiple times. In fact, if the equivalent query is also in RAND (), let's take a look at the different execution plans and execution time

As we all know, in MySQL, if direct order by RAND (), the efficiency is very poor, because it will be executed multiple times. In fact, if the equivalent query is also in RAND (), let's take a look at the different execution plans and execution time

This article shares the C language/c++ how to generate a random number of specific implementation methods for your reference, the specific contents are as follows C language/c++ How to generate random numbers: Here is the rand () function, the

This article uses a case to see how the MySQL optimizer selects the index and JOIN sequence. For Table Structure and data preparation, refer to the test environment at the end of this article. Here we will mainly introduce the main execution process

Summary: Random number in the actual use of very much, such as game design, signal processing, usually we can easily get the average distribution of random numbers. But how do we generate random numbers of other distributions based on the average

Today, database operations are increasingly becoming a performance bottleneck for the entire application, which is especially noticeable for web applications. It's not just about the performance of the database that DBAs need to worry about, it's

E-r DesignMany students are learning SQL statements, it is very difficult, it is because you are learning a database you do not know, the table in the database is not designed by you, the relationship between table and table you do not understand.

Best 20 + Experience sharing for MySQL performance optimizationMySQL the best over 20 experience sharing for performance optimization ....... ............... ....................... ........ 11. Optimize your query for the query cache ....... ..... .

Reference article: http://www.jb51.net/article/24392.htmWhen we design the database table structure, we need to pay attention to the performance of the data operation when we operate the database, especially the SQL statements when we look at the