mysql random sort

Set Change root passwordNote: How to change the root password, about the root user is the MySQL Super administrator user, it is similar to the root user inside the Linux operating system, to distinguish between the root of MySQL and the system root

MySQL Cache Optimization (continued) and mysql Cache Optimization MySQL is cached everywhere. When can I read the MySQL source code and analyze in detail how the cache is used. This part mainly optimizes various explicit cache: Query Cache

Oracle Query result set, random sort Copy Code code as follows: SELECT * FROM table1 ORDER by Dbms_random.value (); MySQL randomly query out a record: Copy Code code as follows: --The following query statement is efficient,

PrefaceIn addition to the regular join statements, there is a class of query statements that are also used more frequently, that is, orderby,group by and distinct. Considering that all three types of queries involve the sorting of data, I put them

The fifth chapter sort retrieves the dataThis chapter teaches you how to use the ORDER BY clause of a SELECT statement to sort the retrieved data as needed.5.1 Sorting DataAs described in the previous chapter, the following SQL statement returns a

Mysql implements random query of bitsCN.com 1. randomly query a piece of data Method 1: SELECT * FROM 'table' order by rand () limit 1 Rating: it is not recommended and the efficiency is very low. it is described in the official document that Order

MySQL Query performance optimizationThe optimization of MySQL query performance involves many aspects, including library table structure, establishing reasonable index and reasonable query. The library table structure includes how to design

Sort mysql Databases and mysql DatabasesDatabase-related 1. InnoDB logs InnoDB has many logs. There are two concepts in logs that need to be clearly divided: Logical logs and physical logs. 1.1 logical logsThe operation information logs are

Understanding MySQL-index and optimization summary, mysql Index Summary Preface: indexes have a crucial impact on the query speed. Understanding indexes is also the starting point for optimizing database performance. Consider the following: Assume

In MySQL, there are two ways to generate an ordered result set: one is using Filesort, and the other is scanning in indexed order. Sorting with an index is very fast, and you can use the same index to find and sort operations at the same time.