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Explain Visualization for MySQL

· 4 min read
PawSQL Team
Optimize your SQL Queries by Clicks!

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Overview

The execution plan is an internal execution strategy generated by the database when executing SQL queries. It describes how the SQL is executed step-by-step internally in the database and is an important basis for diagnosing SQL performance issues and tuning. As the complexity of database applications increases, SQL execution plans become more and more complicated along with the SQL. Relying on plaintext execution plans makes it very challenging to grasp the overall execution plan, locate key paths and bottlenecks, bringing great difficulties to DBAs' performance tuning work.

The visual execution plan tool intuitively presents the execution plan in a flowchart, clearly showing the plan structure. It uses visual elements to highlight key operations and paths, while associating SQL statement source code for integrated analysis. This can greatly improve the efficiency for DBAs to understand and analyze execution plans, quickly locate performance bottlenecks, and perform precise optimization on SQL or indexes.

Node Type of Explain Tree

· 4 min read
PawSQL Team
Optimize your SQL Queries by Clicks!

PostgreSQL

数据访问

SEQ SCAN: 通过顺序扫描输入记录集来查找相关记录,顺序扫描(与索引扫描不同)执行单个读取操作。 CTE SCAN: 对公共表达式(CTE)查询结果执行顺序扫描。请注意,CTE的结果被计算并临时存储(Materialization)。 INDEX SCAN: 根据索引查找相关记录。索引扫描执行两次读取操作:一次读取索引,另一次从表中读取实际值。