7.4 Using mysqldump for Backups (original) (raw)

This section describes how to use mysqldump to produce dump files, and how to reload dump files. A dump file can be used in several ways:

• As a backup to enable data recovery in case of data loss.
• As a source of data for setting up replicas.
• As a source of data for experimentation:
  • To make a copy of a database that you can use without changing the original data.
  • To test potential upgrade incompatibilities.

mysqldump produces two types of output, depending on whether the --tab option is given:

• Without --tab,mysqldump writes SQL statements to the standard output. This output consists ofCREATE statements to create dumped objects (databases, tables, stored routines, and so forth), andINSERT statements to load data into tables. The output can be saved in a file and reloaded later usingmysql to recreate the dumped objects. Options are available to modify the format of the SQL statements, and to control which objects are dumped.
• With --tab,mysqldump produces two output files for each dumped table. The server writes one file as tab-delimited text, one line per table row. This file is named_`tblname`_.txt in the output directory. The server also sends aCREATE TABLE statement for the table to mysqldump, which writes it as a file named_`tblname`_.sql in the output directory.