Python Example: Getting MySQL Database Size

Using the INFORMATION_SCHEMA database:

• Connect to your MySQL server.
• Execute the following query:

SELECT table_schema AS `Database`,
       SUM(data_length + index_length) / 1024 / 1024 AS `Size (MB)`
FROM information_schema.tables
GROUP BY table_schema;   

• This query will return a list of databases and their sizes in megabytes.

Using the SHOW TABLE STATUS command:

SHOW TABLE STATUS FROM `your_database_name`;

• This query will return information about all tables in the specified database, including their data and index sizes. You can calculate the total size by adding up the Data_length and Index_length columns for all tables.

SHOW DATABASE STATUS;

• This query will return information about all databases on the server, including their data and index sizes. You can find the size of a specific database by looking for its name in the Db column and checking the Data_size and Index_size columns.

Using the SHOW TABLE STATUS command and a programming language:

• Connect to your MySQL server using a programming language like PHP, Python, or Java.
• Execute the SHOW TABLE STATUS command and retrieve the results.
• Iterate over the results and calculate the total size by adding up the Data_length and Index_length columns for all tables.

Using a MySQL management tool:

• Connect to your MySQL server using a management tool like phpMyAdmin or MySQL Workbench.
• Navigate to the database you want to check.
• The tool should display the size of the database.

Python Example: Getting MySQL Database Size

Using the mysql-connector-python library:

import mysql.connector

# Connect to your MySQL database
mydb = mysql.connector.connect(
  host="your_host",
  user="your_user",
  passwd="your_password",
  database="your_database"
)

mycursor = mydb.cursor()

# Execute the SQL query to get database size
mycursor.execute("SELECT table_schema AS `Database`, SUM(data_length + index_length) / 1024 / 1024 AS `Size (MB)` FROM information_schema.tables GROUP BY table_schema;")   

myresult = mycursor.fetchall()

# Print the results
for x in myresult:
  print(x)

Explanation:

1. Import the mysql.connector library.
2. Connect to your MySQL database using the provided credentials.
3. Create a cursor object to execute SQL statements.
4. Execute the SQL query to get the database size.
5. Fetch the results and print them.

Note: Replace the placeholders (your_host, your_user, your_password, and your_database) with your actual MySQL connection details.

Using the mysqli extension:

<?php
$servername = "your_host";
$username = "your_user";
$password = "your_password";
$dbname = "your_database";

// Create connection
$conn = new mysqli($servername, $username, $password, $dbname);

// Check connection
if ($conn->connect_error)    {
    die("Connection failed: " . $conn->connect_error);   
}

$sql = "SELECT table_schema AS `Database`, SUM(data_length + index_length) / 1024 / 1024 AS `Size (MB)` FROM information_schema.tables GROUP BY table_schema;";   

$result = $conn->query($sql);

if ($result->num_rows > 0) {
    while($row = $result->fetch_assoc()) {
        echo "Database: " . $row["Database"]. " - Size: " . $row["Size (MB)"] . " MB<br>";
    }
} else {
    echo "0 results";
}

$conn->close();
?>

Alternative Methods for Getting MySQL Database Size

This command provides a direct overview of a database's status, including its size.

SQL Query:

SHOW DATABASE STATUS LIKE 'your_database_name';

• Replace your_database_name with the actual name of your database.
• The result will show various attributes, including Data_size and Index_size. You can sum these values to get the total database size.

Many GUI-based MySQL management tools, like phpMyAdmin or MySQL Workbench, provide a visual interface to view database information. This often includes the database size.

Using a Programming Language's Specific Database Connector

Some programming languages have built-in or third-party libraries that provide functions to interact with MySQL databases. These libraries often offer methods to query database metadata, including size information.

Example in Python using mysql-connector-python:

import mysql.connector

# Connect to your database
mydb = mysql.connector.connect(
  host="your_host",
  user="your_user",
  passwd="your_password",
  database="your_database"
)

# Get database status
cursor = mydb.cursor()
cursor.execute("SHOW DATABASE STATUS LIKE 'your_database_name'")
result = cursor.fetchone()

# Extract size information
data_size = result[1]
index_size = result[2]
total_size = data_size + index_size

print("Total database size:", total_size)

Using the PERCONA-SERVER Plugin

If you're using Percona Server, a fork of MySQL with additional features, you can use the sys schema to get more detailed information about database sizes and performance metrics.

Example:

SELECT * FROM sys.databases;

Considerations for Large Databases