How to Accurately Determine the True Size of a MySQL Database?

Determining the True Size of a MySQL Database

Calculating the size of a MySQL database is essential when selecting a web host. The SHOW TABLE STATUS command provides information about individual tables, but its output can be misleading.

Table Data Size Interpretation

Your query using SHOW TABLE STATUS shows "Data_Length" as 362000 bytes. This value does not represent the total data size for the table. To get the actual data size, you should multiply the row count (400) by the "Avg. Row Length" (55), resulting in 144800000 bytes (144.8 MB). This is the actual data size for this table.

Understanding "Index Length"

"Index Length" refers to the size of the indexes created for the table. Indexes speed up database queries but also consume storage space. The value in "Index Length" is the total size of all indexes combined, which in your case is 66560 bytes (65.07 KB).

Determining Database Size

To determine the overall size of the database, including all tables and indexes, run the following query:

<code class="sql">SELECT table_schema "database name",
    sum( data_length + index_length ) / 1024 / 1024 "database size in MB",
    sum( data_free )/ 1024 / 1024 "free space in MB"
FROM information_schema.TABLES
GROUP BY table_schema;</code>

This query will provide a breakdown of the database size and any available free space. Note that the value in "database size in MB" accurately reflects the true size of your MySQL database.

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