ColumnStore Table Size Limitations

MariaDB ColumnStore has a hard limit of 4096 columns per table.

However, it's likely that you run into other limitations before hitting that limit, including:

• Row size limit of tables. This varies, depending on the storage engine you're using. For example, InnoDB has a row size of 64KB which indirectly limits the number of columns.

• Size limit of .frm files. Those files hold the column description of tables. Column descriptions vary in length. Once all column descriptions combined reach a length of 64KB, the table's .frm file is full, limiting the number of columns you can have in a table.

Given that, the maximum number of columns a ColumnStore table can effectively have is around 2000 columns.