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You can also store the dump in a file, transfer the file to the target machine, and then load the file into the database there. For example, you can dump a database to a compressed file on the source machine like this: 

mysqldump --quick db_name  | gzip > db_name .gz 

Transfer the file containing the database contents to the target machine and run these commands there: 

mysqladmin create db_name gunzip < db_name .gz | mysql db_name 

You can also use mysqldump  and mysqlimport  to transfer the database. For large tables, this is much faster than simply using mysqldump . In the following commands, DUMPDIR  represents the full path name of the directory you use to store the output from mysqldump . 

First, create the directory for the output files and dump the database: 

mkdir DUMPDIR mysqldump --tab= DUMPDIR db_name 

Then transfer the files in the DUMPDIR  directory to some corresponding directory on the target machine and load the files into MySQL there: 

mysqladmin create db_name # create database cat DUMPDIR /*.sql | mysql db_name # create tables in database mysqlimport db_name DUMPDIR /*.txt # load data into tables 

Do not forget to copy the mysql  database because that is where the grant tables are stored. You might have to run commands as the MySQL root  user on the new machine until you have the mysql  database in place. 

After you import the mysql  database on the new machine, execute mysqladmin flush-privileges so that the server reloads the grant table information. 

## 2.12 Downgrading MySQL 

Downgrade from MySQL 8.0 to MySQL 5.7, or from a MySQL 8.0 release to a previous MySQL 8.0 release, is not supported. The only supported alternative is to restore a backup taken before  upgrading. It is therefore imperative that you back up your data before starting the upgrade process. 

## 2.13 Perl Installation Notes 

The Perl DBI  module provides a generic interface for database access. You can write a DBI  script that works with many different database engines without change. To use DBI , you must install the DBI  module, as well as a DataBase Driver (DBD) module for each type of database server you want to access. For MySQL, this driver is the DBD::mysql  module. 

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## Note 

Perl support is not included with MySQL distributions. You can obtain the necessary modules from http://search.cpan.org for Unix, or by using the ActiveState ppm program on Windows. The following sections describe how to do this. 

