Partitions' physical files

If @@innodb_file_per_table is set to OFF when the table is partitioned, all partitions are stored in the InnoDB system tablespace, but in different areas. If this variable is set to 1, each partition is stored in a different file.

Storage engines that store data and indexes in separate files, such as Aria and MyISAM, create a data file and an index file for each partition.

The extension of partition data or index files is the same that is used for unpartitioned tables. The basename of the files is the name of the table, plus #P#, plus the name of the partition. So, the name pattern is as follows:

<table_name>#P#<partition_name>.<extension>

Like all tables, partitioned tables have a .frm file that contains the table definition. They also have a file with partitions' definitions, which has a .par extension.

For example, let's suppose we have an InnoDB table called employee, with two partitions called p0 and p1. We will have the following files:

employee...