In practice, the DESCRIBE keyword is more often used to obtain information about table structure, whereas EXPLAIN is used to obtain a query execution plan (that is, an explanation of how MySQL would execute a query).
How do I find MySQL query plan?
To view a visual explain execution plan, execute your query from the SQL editor and then select Execution Plan within the query results tab. The execution plan defaults to Visual Explain , but it also includes a Tabular Explain view that is similar to what you see when executing EXPLAIN in the MySQL client.
Which command will show execution plan of query?
You can use the Apache Hive EXPLAIN command to display the actual execution plan that Hive query engine generates and uses while executing any query in the Hadoop ecosystem.
What is query execution plan in MySQL?
A query on a huge table can be performed without reading all the rows; a join involving several tables can be performed without comparing every combination of rows. The set of operations that the optimizer chooses to perform the most efficient query is called the “query execution plan”, also known as the EXPLAIN plan.
What is a query execution plan in SQL?
A query plan (or query execution plan) is a sequence of steps used to access data in a SQL relational database management system. … When a query is submitted to the database, the query optimizer evaluates some of the different, correct possible plans for executing the query and returns what it considers the best option.
How do I see MySQL performance queries?
or using <select your MySQL cluster> → Query Monitor → Running Queries (which will discuss later) to view the active processes, just like how a SHOW PROCESSLIST works but with better control of the queries.
Does MySQL have execution plan?
Its job is to design an optimal MySQL query execution plan for every single query that is executed. The MySQL explain plan allows you to view the plan by using the EXPLAIN keyword as a prefix to your request.
How do I get a plan handle query plan?
To retrieve a snapshot of all query plans residing in the plan cache, retrieve the plan handles of all query plans in the cache by querying the sys. dm_exec_cached_plans dynamic management view. The plan handles are stored in the plan_handle column of sys. dm_exec_cached_plans .
How do I find an execution plan?
To display the estimated execution plan for a query
- On the toolbar, click Database Engine Query. …
- Enter the query for which you would like to display the estimated execution plan.
- On the Query menu, click Display Estimated Execution Plan or click the Display Estimated Execution Plan toolbar button.
How do I enable show plan in SQL?
Use SQL Server Profiler
- Start SQL Server Profiler.
- In the File menu, select New Trace.
- In the Events Section tab, check Show all events.
- Expand the Performance node.
- Select Showplan XML.
- Execute the query you want to see the query plan for.
- Stop the trace. …
- Select the query plan in the grid.
How SQL query works internally in MySQL?
SQL Query mainly works in three phases .
- 1) Row filtering – Phase 1: Row filtering – phase 1 are done by FROM, WHERE , GROUP BY , HAVING clause.
- 2) Column filtering: Columns are filtered by SELECT clause.
- 3) Row filtering – Phase 2: Row filtering – phase 2 are done by DISTINCT , ORDER BY , LIMIT clause.
How can we optimize a SQL query?
It’s vital you optimize your queries for minimum impact on database performance.
- Define business requirements first. …
- SELECT fields instead of using SELECT * …
- Avoid SELECT DISTINCT. …
- Create joins with INNER JOIN (not WHERE) …
- Use WHERE instead of HAVING to define filters. …
- Use wildcards at the end of a phrase only.
How do you use PT visual?
You can pipe input into pt-visual-explain or specify a filename at the command line, including the magical ‘-‘ filename, which will read from standard input. It can do two things with the input: parse it for something that looks like EXPLAIN output, or connect to a MySQL instance and run EXPLAIN on the input.
Where is query plan in SQL Server?
On the SQL Server Management Studio toolbar, click Database Engine Query. You can also open an existing query and display the estimated execution plan by clicking the Open File toolbar button and locating the existing query. Enter the query for which you would like to display the actual execution plan.
How do you read a query plan?
Query Execution Plans are typically read right to left top to bottom. There is also arrows between operations which represent the data flowing between the objects. The thickness of the arrow also indicates how much data is being processed.
How do you create an execution plan?
Business Execution Plan Milestones
- Prove your concept works, both technically and as a business.
- Finish your design specifications.
- Create a working prototype.
- Raise capital.
- Ship a testable version of your product to your first customers.
- Ship the final version of your product to customers.