Find Database Sizes in MySQL/MariaDB Database Server

Are you trying to find which databases in your MySQL/MariaDB database server has large tablespace?. People have varying reasons for finding database sizes in MySQL/MariaDB. It could be for data truncation, data archiving, table optimizations among many other applications.

In this how-to guide, I’ll share with you a query you can use in your MySQL/MariaDB database server to find the size of each Database.

Launch MySQL / MariaDB shell console:

$ mysql -u root -p

Run the query below:

SELECT
	COUNT(*) AS Total_Table_Count
	,table_schema
	,CONCAT(ROUND(SUM(table_rows)/1000000,2),'M') AS Total_Row_Count
	,CONCAT(ROUND(SUM(data_length)/(1024*1024*1024),2),'G') AS Total_Table_Size
	,CONCAT(ROUND(SUM(index_length)/(1024*1024*1024),2),'G') AS Total_Table_Index
	,CONCAT(ROUND(SUM(data_length+index_length)/(1024*1024*1024),2),'G') Total_Size
FROM information_schema.TABLES
GROUP BY table_schema
ORDER BY SUM(data_length+index_length)
DESC LIMIT 10;

This query will:

• Find the number of tables in each database
• Total number of rows in a database
• Total table size and Index
• Total table size in GB

Below is a sample output:

+-------------------+--------------------+-----------------+------------------+-------------------+------------+
| Total_Table_Count | table_schema       | Total_Row_Count | Total_Table_Size | Total_Table_Index | Total_Size |
+-------------------+--------------------+-----------------+------------------+-------------------+------------+
|               124 | b4gaags_db         | 1.72M           | 0.10G            | 0.06G             | 0.16G      |
|                33 | mutima             | 0.44M           | 0.10G            | 0.03G             | 0.13G      |
|                55 | gitea              | 0.00M           | 0.00G            | 0.00G             | 0.00G      |
|                48 | kanboard           | 0.00M           | 0.00G            | 0.00G             | 0.00G      |
|                31 | mysql              | 0.00M           | 0.00G            | 0.00G             | 0.00G      |
|                76 | information_schema | NULL            | 0.00G            | 0.00G             | 0.00G      |
|                 3 | zourfs             | 0.00M           | 0.00G            | 0.00G             | 0.00G      |
|                52 | performance_schema | 0.07M           | 0.00G            | 0.00G             | 0.00G      |
+-------------------+--------------------+-----------------+------------------+-------------------+------------+
8 rows in set (0.027 sec)

The ORDER BY DESC LIMIT 10 will show the database sizes from the largest to smallest. Adjust the LIMIT 10 to print more records.

Best Udemy Video Courses to Learn MySQL / MariaDB Databases:

• The Ultimate MySQL Bootcamp: Go from SQL Beginner to Expert
• SQL – MySQL for Data Analytics and Business Intelligence
• MySQL, SQL and Stored Procedures from Beginner to Advanced
• SQL for Beginners: Learn SQL using MySQL and Database Design
• The Complete MySQL Developer Course
• MySQL Database Administration: Beginner SQL Database Design
• Learn Database Design with MySQL