How to get the sizes of the tables of a MySQL database?

Question

I can run this query to get the sizes of all tables in a MySQL database:

show table status from myDatabaseName;

I would like some help in understanding the results. I am looking for tables with the largest sizes.

Which column should I look at?

Answer 1

You can use this query to show the size of a table (although you need to substitute the variables first):

SELECT 
    table_name AS `Table`, 
    round(((data_length + index_length) / 1024 / 1024), 2) `Size in MB` 
FROM information_schema.TABLES 
WHERE table_schema = "$DB_NAME"
    AND table_name = "$TABLE_NAME";

or this query to list the size of every table in every database, largest first:

SELECT 
     table_schema as `Database`, 
     table_name AS `Table`, 
     round(((data_length + index_length) / 1024 / 1024), 2) `Size in MB` 
FROM information_schema.TABLES 
ORDER BY (data_length + index_length) DESC;

Answer 2

SELECT TABLE_NAME AS "Table Name", 
table_rows AS "Quant of Rows", ROUND( (
data_length + index_length
) /1024, 2 ) AS "Total Size Kb"
FROM information_schema.TABLES
WHERE information_schema.TABLES.table_schema = 'YOUR SCHEMA NAME/DATABASE NAME HERE'
LIMIT 0 , 30

You can get schema name from "information_schema" -> SCHEMATA table -> "SCHEMA_NAME" column

---

Additional You can get size of the mysql databases as following.

SELECT table_schema "DB Name", 
Round(Sum(data_length + index_length) / 1024 / 1024, 1) "DB Size in MB" 
FROM   information_schema.tables 
GROUP  BY table_schema; 

Result

DB Name              |      DB Size in MB

mydatabase_wrdp             39.1
information_schema          0.0

You can get additional details in here.

Answer 3

SELECT 
    table_name AS "Table",  
    round(((data_length + index_length) / 1024 / 1024), 2) as size   
FROM information_schema.TABLES  
WHERE table_schema = "YOUR_DATABASE_NAME"  
ORDER BY size DESC; 

This sorts the sizes (DB Size in MB).

Answer 4

If you want a query to use currently selected database. simply copy paste this query. (No modification required)

SELECT table_name ,
  round(((data_length + index_length) / 1024 / 1024), 2) as SIZE_MB
FROM information_schema.TABLES
WHERE table_schema = DATABASE() ORDER BY SIZE_MB DESC;

Answer 5

• Size of all tables:

  Suppose your database or TABLE_SCHEMA name is "news_alert". Then this query will show the size of all tables in the database.

  SELECT
    TABLE_NAME AS `Table`,
    ROUND(((DATA_LENGTH + INDEX_LENGTH) / 1024 / 1024),2) AS `Size (MB)`
  FROM
    information_schema.TABLES
  WHERE
    TABLE_SCHEMA = "news_alert"
  ORDER BY
    (DATA_LENGTH + INDEX_LENGTH)
  DESC;
  

  Output:

      +---------+-----------+
      | Table   | Size (MB) |
      +---------+-----------+
      | news    |      0.08 |
      | keyword |      0.02 |
      +---------+-----------+
      2 rows in set (0.00 sec)
  

• For the specific table:

  Suppose your TABLE_NAME is "news". Then SQL query will be-

  SELECT
    TABLE_NAME AS `Table`,
    ROUND(((DATA_LENGTH + INDEX_LENGTH) / 1024 / 1024),2) AS `Size (MB)`
  FROM
    information_schema.TABLES
  WHERE
      TABLE_SCHEMA = "news_alert"
    AND
      TABLE_NAME = "news"
  ORDER BY
    (DATA_LENGTH + INDEX_LENGTH)
  DESC;
  

  Output:

  +-------+-----------+
  | Table | Size (MB) |
  +-------+-----------+
  | news  |      0.08 |
  +-------+-----------+
  1 row in set (0.00 sec)
  

Answer 6

There is an easy way to get many informations using Workbench:

• Right-click the schema name and click "Schema inspector".

• In the resulting window you have a number of tabs. The first tab "Info" shows a rough estimate of the database size in MB.

• The second tab, "Tables", shows Data length and other details for each table.

Answer 7

Try the following shell command (replace DB_NAME with your database name):

mysql -uroot <<<"SELECT table_name AS 'Tables', round(((data_length + index_length) / 1024 / 1024), 2) 'Size in MB' FROM information_schema.TABLES WHERE table_schema = \"DB_NAME\" ORDER BY (data_length + index_length) DESC;" | head

For Drupal/drush solution, check the following example script which will display the biggest tables in use:

#!/bin/sh
DB_NAME=$(drush status --fields=db-name --field-labels=0 | tr -d '\r\n ')
drush sqlq "SELECT table_name AS 'Tables', round(((data_length + index_length) / 1024 / 1024), 2) 'Size in MB' FROM information_schema.TABLES WHERE table_schema = \"${DB_NAME}\" ORDER BY (data_length + index_length) DESC;" | head -n20

Answer 8

Heres another way of working this out from using the bash command line.

for i in mysql -NB -e 'show databases'; do echo $i; mysql -e "SELECT table_name AS 'Tables', round(((data_length+index_length)/1024/1024),2) 'Size in MB' FROM information_schema.TABLES WHERE table_schema =\"$i\" ORDER BY (data_length + index_length) DESC" ; done

Answer 9

If you are using phpmyadmin then just go to the table structure

e.g.

Space usage
Data    1.5 MiB
Index   0   B
Total   1.5 Mi

Answer 10

Adapted from ChapMic's answer to suite my particular need.

Only specify your database name, then sort all the tables in descending order - from LARGEST to SMALLEST table inside selected database. Needs only 1 variable to be replaced = your database name.

SELECT 
table_name AS `Table`, 
round(((data_length + index_length) / 1024 / 1024), 2) AS `size`
FROM information_schema.TABLES 
WHERE table_schema = "YOUR_DATABASE_NAME_HERE"
ORDER BY size DESC;

Answer 11

Another way of showing the number of rows and space occupied and ordering by it.

SELECT
     table_schema as `Database`,
     table_name AS `Table`,
     table_rows AS "Quant of Rows",
     round(((data_length + index_length) / 1024 / 1024/ 1024), 2) `Size in GB`
FROM information_schema.TABLES
WHERE table_schema = 'yourDatabaseName'
ORDER BY (data_length + index_length) DESC;  

The only string you have to substitute in this query is "yourDatabaseName".

Answer 12

If you have ssh access, you might want to simply try du -hc /var/lib/mysql (or different datadir, as set in your my.cnf) as well.

Answer 13

I find the existing answers don't actually give the size of tables on the disk, which is more helpful. This query gives more accurate disk estimate compared to table size based on data_length & index. I had to use this for an AWS RDS instance where you cannot physically examine the disk and check file sizes.

select NAME as TABLENAME,FILE_SIZE/(1024*1024*1024) as ACTUAL_FILE_SIZE_GB
, round(((data_length + index_length) / 1024 / 1024/1024), 2) as REPORTED_TABLE_SIZE_GB 
from INFORMATION_SCHEMA.INNODB_SYS_TABLESPACES s
join INFORMATION_SCHEMA.TABLES t 
on NAME = Concat(table_schema,'/',table_name)
order by FILE_SIZE desc

Answer 14

SELECT TABLE_NAME AS table_name, 
table_rows AS QuantofRows, 
ROUND((data_length + index_length) /1024, 2 ) AS total_size_kb 
FROM information_schema.TABLES
WHERE information_schema.TABLES.table_schema = 'db'
ORDER BY (data_length + index_length) DESC; 

all 2 above is tested on mysql

Answer 15

This should be tested in mysql, not postgresql:

SELECT table_schema, # "DB Name", 
Round(Sum(data_length + index_length) / 1024 / 1024, 1) # "DB Size in MB" 
FROM   information_schema.tables 
GROUP  BY table_schema; 

Answer 16

Calculate the total size of the database at the end:

(SELECT 
  table_name AS `Table`, 
  round(((data_length + index_length) / 1024 / 1024), 2) `Size in MB` 
  FROM information_schema.TABLES 
  WHERE table_schema = "$DB_NAME"
)
UNION ALL
(SELECT 
  'TOTAL:',
  SUM(round(((data_length + index_length) / 1024 / 1024), 2) )
  FROM information_schema.TABLES 
  WHERE table_schema = "$DB_NAME"
)

Answer 17

select x.dbname as db_name, x.table_name as table_name, x.bytesize as the_size from
  (select
     table_schema as dbname,
     sum(index_length+data_length) as bytesize,
     table_name
   from
     information_schema.tables
   group by table_schema
  ) x
where
  x.bytesize > 999999
order by x.bytesize desc;