The EXPLAIN keyword is used to obtain information about how our SQL databases execute the queries in MySQL. It is synonyms to the DESCRIBE statement. In practice, the DESCRIBE keyword provides table structure information, whereas the EXPLAIN keyword gives the query execution plan.
The IN operator allows you to specify multiple values in a WHERE clause. The IN operator is a shorthand for multiple OR conditions.
The EXPLAIN statement ( explain_statement) describes the search strategy used internally by the database system for a QUERY statement or SINGLE SELECT statement (statements for searching for certain rows in specific tables).
What are the main features of MySQL?
Open-Source. MySQL is open-source, which means this software can be downloaded, used and modified by anyone. Quick and Reliable. Scalable. Data Types. Character Sets. Secure. Support for large databases. Client and Utility Programs.
Like most database management systems out there, MySQL has a client-server architecture and can be used in a networked environment. The server program resides on the same physical or virtual system where the database files are stored, and it is responsible for all interactions with the databases.
One of the reasons MySQL is the world’s most popular open source database is that it provides comprehensive support for every application development need. Within the database, support can be found for stored procedures, triggers, functions, views, cursors, ANSI-standard SQL, and more.
Finally, it’s an overview of MySQL and it is not a programming language rather it is software used for the database management system.
SQL is a query programming language that manages RDBMS. MySQL is a relational database management system that uses SQL. SQL is primarily used to query and operate database systems. MySQL allows you to handle, store, modify and delete data and store data in an organized way.
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.
The EXPLAIN PLAN statement displays execution plans chosen by the Oracle optimizer for SELECT , UPDATE , INSERT , and DELETE statements. A statement’s execution plan is the sequence of operations Oracle performs to run the statement. The row source tree is the core of the execution plan.
In Data Manipulation Language(DML), we have four different SQL statements, Select, Insert, Update, and Delete.
In MySQL there are three main data types: string, numeric, and date and time.
In MySQL, a key is a data item that identifies a record exclusively. In other terms, the key is a group of columns used to uniquely define a record in a table. It is used to retrieve or extract rows from a table as needed.
As of MySQL Version 3.23. 6, you can choose between three basic table formats: ISAM, HEAP, and MyISAM. Newer MySQL may support additional table types (InnoDB, or BDB), depending on how you compile it. When you create a new table, you can tell MySQL which table type it should use for the table.
MySQL is a relational database management system (RDBMS) developed by Oracle that is based on structured query language (SQL). A database is a structured collection of data.
Basically mySQL stores data in files in your hard disk. It stores the files in a specific directory that has the system variable “datadir”.
The monitoring agent can be configured to collect data directly from the MySQL server, using a query. This enables you to extend the functionality of the agent and create custom advisors which analyze the data collected by the custom data collection. To create a custom data collection, you must add a class to custom.
