What is the default setting for innodb_data_file_path if it isn't specified in my.cnf?

Question

What is the default setting for innodb_data_file_path if it isn't specified in my.cnf?

When I try to execute the following command on a 12GB table full of pictures

alter table `rails_production`.`pictures` change `data` `image_file_data` mediumblob NULL;

I get the following error

ERROR 1114 (HY000): The table '#sql-7fe4_12c9' is full

I read another StackOverflow question link text that suggested I change my setting to the following

innodb_data_file_path = ibdata1:10M:autoextend:max:512M

When I looked in my.cnf I noticed I didn't have any settings for innodb_data_file_path, I'm wondering what the default value is?

Answer 1

I just learned about

show variables;

Which will show you the value of those configuration options, in my case it was

| innodb_data_file_path           | ibdata1:10M:autoextend      |