MySQL databases are generally pretty good about dealing with large size tables with indexes, however sometimes it’s good to know just how large a DB is so you can optimize it if necessary. In a lot of cases it’s not very easy to just look up the size of the table, and as such, the ability to run a SQL query to return that info is helpful. Here is the query that can help:

SELECT table_name AS "Table",
ROUND(((data_length + index_length) / 1024 / 1024), 2) AS "Size (MB)"
FROM information_schema.TABLES
WHERE table_schema = "YOUR_TABLE_NAME"
ORDER BY (data_length + index_length) DESC;

Be sure to update the YOUR_TABLE_NAME to the name of your DB table.

To get DB size on all DB’s in an instance:

SELECT table_schema AS "Database", SUM(data_length + index_length) / 1024 / 1024 / 1024 AS "Size (GB)" FROM information_schema.TABLES GROUP BY table_schema

This will return the full DB size for all tables on a MySQL/Maria instance.