Shulou(Shulou.com)06/01 Report--

This article mainly introduces the circumstances of sql optimization in MySQL, which is very detailed and has a certain reference value. Friends who are interested must finish it!

Brief introduction of sql Optimization 1. Under what circumstances to optimize sql

Low performance, too long execution time, too long waiting time, join query, index failure.

2. Sql statement execution process

(1) Writing process

Select distinct... From... Join... On... Where... Group by... Having... Order by... Limit...

(2) Analytical process

From... On... Join... Where... Group by... Having... Select distinct... Order by... Limit. 3. Sql optimization is to optimize the index

An index is equivalent to a catalogue of books.

The data structure of the index is a B + tree.

The above is all the contents of the article "when to optimize sql in MySQL". Thank you for reading! Hope to share the content to help you, more related knowledge, welcome to follow the industry information channel!

Welcome to subscribe "Shulou Technology Information " to get latest news, interesting things and hot topics in the IT industry, and controls the hottest and latest Internet news, technology news and IT industry trends.