MySQL explains how it would process the statement, including information about how tables are joined and in which order. For information about using EXPLAIN to obtain execution plan information, see Section 8.8.2, “EXPLAIN Output Format”. 当...
在优化sql语句时,我们经常会用到explain语句,这里对explain语句做一个详细的总结说明。 The EXPLAIN statement provides information about how MySQL executes statements. EXPLAIN works with SELECT, DELETE, INSERT, REPLACE, and UPDATE statements. 通过一个实例来说明explain的用法,其实使用很简单,主要是通过实例来介...
If SQL query performance is poor or query results do not meet expectations, you can execute the EXPLAIN and EXPLAIN ANALYZE statements in Hologres to obtain execution plans of query statements. This way, you can optimize query statements or database structures. This topic describes how to execute...
MySQL explains howit would process the statement, including information about how tables are joinedand in which order. EXPLAIN EXTENDED can be used to provide additionalinformation.
DISTSQL(Default)Generate a link to a distributed SQL physical query plan tree. For more information, seeDefault option. DEBUGNew in v20.1:Generate a ZIP file containing files with detailed information about the query and the database objects referenced in the query. For more information, seeDEBU...
In addition to these features, the extension allows you to view information about your SQL Server’s configuration and storage utilization. SQL Server licensing models There are several different options related to how SQL Server is licensed when using the Azure IaaS offering. ...
In a SQL Server environment, blob storage will typically be used for database backups, using SQL Server’s back up to URL functionality. File Storage - File storage is effectively a file share that can be mounted inside a virtual machine, without the n...
摘要: DBA经常会用到的explain来查看SQL语句的执行计划,今天小人斗胆,从MySQL 5.7 Reference Manual中把MySQL EXPLAIN Output Format翻译过来。欢迎拍砖 Explain语句提供了一个select语句执行计划的信息。 Explain为每个用了select语句的表,返回一行信息。它列出了表中的顺序输出,MySQL会读取他们,然后再处理。MySQL解决了所...
SQL Script: Table Creation and Data Insertion -- Create the stores table CREATE TABLE IF NOT EXISTS stores ( id SMALLINT PRIMARY KEY, name VARCHAR(50) NOT NULL, location VARCHAR(100) ); -- Create the sales_stats table CREATE TABLE IF NOT EXISTS sales_stats ( ...
Plan information cannot be collected for SQL statements that failed to be executed. Data in PLAN_TABLE is in a session-level lifecycle. Sessions are isolated from users, and therefore users can only view the data of the current session and current user. PLAN_TABLE cannot be joined with GDS ...