When I export a database in MySQL, it gives me a
.sql file. Let's say this
.sql file is 80 MB.
Are they compressed in order to reduce disk space usage?
Is that 80MB real physical-storage size?
It depends on how you export your database:
if you use
you can compress it manually or in one commandline like this:
if your question is, if the tables are stored compressed in the working directory, there are some possibilities:
if you have MyISAM tables that would work if they are read-only, you can Generate Compressed, Read-Only MyISAM Tables with myisampack
And by setting InnoDB configuration options, you can create tables where the data is stored in compressed form.
just alter the table to add the compressed option: