I have an InnoDB table which looks like this right now:
The table is around 126GB big, but I have read that InnoDB's default can hold up to 64 TB of data. Is this correct?
I ask because of the column "Data Free" which is very small compared to "Data Length" and soon will be 0 I guess.
Do I need to do something here? I mean 126GB is nothing compared to 64 TB.
Does MySQL manage this all by itself?
Thank you very much!
Answers
Yes, your understanding is correct. InnoDB, which is the default storage engine for MySQL, can support much larger data sizes than the 126GB you currently have. The maximum size for an InnoDB tablespace is indeed 64TB, as you mentioned.
The "Data Free" column in the output you provided indicates the amount of unused space within the tablespace. InnoDB manages this space automatically, reusing it as needed for new data inserts, updates, and deletes. When you delete rows from a table, InnoDB doesn't necessarily release the space immediately; instead, it marks it as available for reuse. This is why you see the "Data Free" column gradually decreasing over time.
As long as you have enough disk space available for your database to grow, and as long as InnoDB is not reporting any errors or warnings about space constraints, you don't need to do anything special. InnoDB will manage the space allocation and reuse automatically.
However, if you want to reclaim the unused space and reduce the table size, you can consider using the OPTIMIZE TABLE command. This command rebuilds the table, reclaiming unused space and potentially improving performance. Keep in mind that running OPTIMIZE TABLE on a large table can take a significant amount of time and may impact database performance during the operation, so it's usually best to do it during off-peak hours.
