In my last post, “A closer look at the MySQL ibdata1 disk space issue and big tables,” I looked at the growing ibdata1 problem under the perspective of having big tables residing inside the so-called shared tablespace. In the particular case that motivated that post, we had a customer running out of disk space in his server who was looking for a way to make the ibdata1 file shrink. As you may know, that file (or, as explained there, the set of ibdata files composing the shared tablespace) stores all InnoDB tables created when innodb_file_per_table is disabled, but also other InnoDB structures, such as undo logs and data dictionary.

For example, when you run a transaction involving InnoDB tables, MySQL will first write all the changes it triggers in an undo log, for the case you later …

In my last post, “A closer look at the MySQL ibdata1 disk space issue and big tables,” I looked at the growing ibdata1 problem under the perspective of having big tables residing inside the so-called shared tablespace. In the particular case that motivated that post, we had a customer running out of disk space in his server who was looking for a way to make the ibdata1 file shrink. As you may know, that file (or, as explained there, the set of ibdata files composing the shared tablespace) stores all InnoDB tables created when innodb_file_per_table is disabled, but also other InnoDB structures, such as undo logs and data dictionary.

For example, when you run a transaction involving InnoDB tables, MySQL will first write all the changes it triggers in an undo log, for the case you later decide to …

A recurring and very common customer issue seen here at the Percona Support team involves how to make the ibdata1 file “shrink” within MySQL. I can only imagine there’s a degree of regret by some of the InnoDB architects on their design decisions regarding disk-space management by the shared tablespace* because this has been a big frustration for many MySQL users over the years.

There’s a very old bug (“InnoDB ibdata1 never shrinks after data is removed,” Sept. 8 2003) documenting user dissatisfaction. Shortly before that issue celebrated its 10th anniversary, James Day, MySQL senior principal support engineer at Oracle, posted a comment explaining why things haven’t changed and he also offered possible alternative solutions. Maybe we’ll …

A recurring and very common customer issue seen here at the Percona Support team involves how to make the ibdata1 file “shrink” within MySQL. I can only imagine there’s a degree of regret by some of the InnoDB architects on their design decisions regarding disk-space management by the shared tablespace* because this has been a big frustration for many MySQL users over the years.

There’s a very old bug (“InnoDB ibdata1 never shrinks after data is removed,” Sept. 8 2003) documenting user dissatisfaction. Shortly before that issue celebrated its 10th anniversary, James Day, MySQL senior principal support engineer at Oracle, posted a comment explaining why things haven’t changed and he also offered possible alternative solutions. Maybe we’ll …

We receive this question about the ibdata1 file in MySQL very often in Percona Support.

The panic starts when the monitoring server sends an alert about the storage of the MySQL server – saying that the disk is about to get filled.

After some research you realize that most of the disk space is used by the InnoDB’s shared tablespace ibdata1. You have innodb_file_per_table enabled, so the question is:

What is stored in ibdata1?

When you have innodb_file_per_table enabled, the tables are stored in their own tablespace but the shared tablespace is still used to store other InnoDB’s internal …