WordPress database growing dramatically in size despite adding no new content

Question

Some plugins aggregate data over time without ever cleaning up. I remember Broken Link Checker did that back in the days when I was using it …

The first step: Find all tables, count their size (data, indexes and total size).

Sample query, DB_NAME is the constant from your wp-config.php:

SELECT
    table_name,
    table_rows,
    concat(round(data_length/(1024*1024),2), 'M') data,
    concat(round(index_length/(1024*1024),2), 'M') idx,
    concat(round((data_length + index_length)/1024,2), 'M') total_size
    FROM information_schema.TABLES
    WHERE information_schema.TABLES.table_schema="DB_NAME"
    ORDER BY (data_length+index_length) DESC;

Then watch how they grow, identify the plugin writing into these tables.

I am using a very simple plugin for that … published right now: T5 Table size dashboard widget. As the name says, it shows tables stats in a dashboard widget.

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I would recommend to disable all plugins you don’t need. And if you don’t want to add more content this thread might be worth a look: Create a Static HTML Site from WordPress