Mysql – thesqldump has a “quick” option. Why isn’t this enabled by default

MySQLoptions

In the mysqldump docs I see a "–quick" option, however there is no indication as to why somebody would want this disabled. What are the disadvantages to enabling it or why is it even an option? Shouldn't it just be always on?

http://dev.mysql.com/doc/refman/5.7/en/mysqldump.html#option_mysqldump_quick


edit: While it's been made clear to me that it is enabled by default, this isn't too clear the from the official documentation (especially when some samples specify the option: http://dev.mysql.com/doc/refman/5.7/en/copying-databases.html). The table of options does not have a field specifying the defaults and the description of –quick has no note that it's included by –opt. I'll leave the question title as it was so that others looking for the same thing via Google can find the information easily.

Best Answer

--quick is on by default, as it is one of the options included in --opt, which is itself on by default.

From the man page:

  • Use of --opt is the same as specifying --add-drop-table, --add-locks, --create-options, --disable-keys, --extended-insert, --lock-tables, --quick, and --set-charset. All of the options that --opt stands for also are on by default because --opt is on by default.

The page you linked to contains similar information.

  • --opt

    This option, enabled by default, is shorthand for the combination of --add-drop-table --add-locks --create-options --disable-keys --extended-insert --lock-tables --quick --set-charset. It gives a fast dump operation and produces a dump file that can be reloaded into a MySQL server quickly.