Update (noted by Jocelyn Fournier).

supported. See @ref{Fulltext Search} for details of operation.

@item

The @code{FOREIGN KEY}, @code{CHECK}, and @code{REFERENCES} clauses don't

actually do anything.  The syntax for them is provided only for compatibility,

to make it easier to port code from other SQL servers and to run applications

that create tables with references.

@xref{Differences from ANSI}.

In MySQL Version 3.23.44 or later, @code{InnoDB} tables support checking of

foreign key constraints. @xref{InnoDB}.

For other table types, MySQL Server does parse the @code{FOREIGN KEY},

@code{CHECK}, and @code{REFERENCES} syntax in @code{CREATE TABLE} commands,

but without further action being taken. @xref{ANSI diff Foreign Keys}.

@item

Each @code{NULL} column takes one bit extra, rounded up to the nearest byte.