Exporting Structure and Data - Mastering phpMyAdmin 2.11 for Effective MySQL Management - page 130

Multi-Database Exports
Any user can export the databases to which he or she has access, in one operation.
On the Home page, the Export link brings us to the screen shown on the following
page, which has the same structure as the other export pages, except for the
databases list:
Exporting large databases may or may not work: this depends on their
size, the options chosen, and the web server's PHP component settings
(especially memory size and execution time).
Saving the Export File on the Server
Instead of transmitting the export file over the network with HTTP, it is possible to
save it directly on the file system of the web server. This could be quicker and less
sensitive to execution time limits, because the whole transfer from server to client
browser is bypassed. Eventually, a file transfer protocol like FTP or SFTP can be used
to retrieve the file, because leaving it on the same machine would not provide good
backup protection.
A special directory has to be created on the web server before saving an export file
on it. Usually, this is a subdirectory of the main phpMyAdmin directory. We will use
save_dir as an example. This directory must have special permissions. First, the
web server must have write permissions for this directory. Also, if the web server's
PHP component is running in safe mode, the owner of the phpMyAdmin scripts
must be the same as the owner of save_dir .