MySQL Database (Schema) Sizes
Ranks each schema by total size and table count. Used for capacity tracking and growth analysis.
SELECT table_schema,
COUNT(*) AS tables,
ROUND(SUM(data_length) / 1024 / 1024 / 1024, 2) AS data_gb,
ROUND(SUM(index_length) / 1024 / 1024 / 1024, 2) AS index_gb,
ROUND(SUM(data_length + index_length) / 1024 / 1024 / 1024, 2) AS total_gb
FROM information_schema.tables
GROUP BY table_schema
ORDER BY SUM(data_length + index_length) DESC;Verify in a staging environment prior to running in production. This is a read-only diagnostic query; it does not acquire exclusive locks.
- This script is designed for read-only diagnostics; it does not alter schema or modify data directly.
- Prior to executing on production systems under high load, verify the target database version (Min. Version: 5.7).
- Exercise caution with mutating actions (e.g., terminating sessions or dropping indexes) referenced in the notes section.
Engineering Triad: Related Runbooks & Incident Response
Which production incidents and emergency drills execute this script as a diagnosis step?
Other MYSQL Diagnostic Scripts
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Lists active queries running longer than 60 seconds from the processlist. Fast diagnosis for slowdowns and lock pile-ups.
Find MySQL InnoDB Lock Waits and the Blocking Query
Uses the sys schema to show waiting and blocking sessions with lock modes. Resolves who is holding up whom in a single query.
List the Largest Tables and Disk Usage in MySQL
Ranks tables by data, index and free space size. Core input for capacity planning and archiving decisions.
Detect Unused Indexes in MySQL
Uses sys.schema_unused_indexes to list indexes that were never used. Helps safely drop indexes that slow down writes.