manual.texi:

option = QUICK | FAST | MEDIUM | EXTENDED | CHANGED

@end example

@code{CHECK TABLE} only works on @code{MyISAM} tables. On

@code{CHECK TABLE} only works on @code{MyISAM} and @code{InnoDB} tables. On

@code{MyISAM} tables it's the same thing as running @code{myisamchk -m

table_name} on the table.

You can find a discussion about different locking methods in the appendix.

@xref{Locking methods}.

All locking in MySQL is deadlock-free.  This is managed by always

All locking in MySQL is deadlock-free, except for @code{InnoDB} and

@code{BDB} type tables.

This is managed by always

requesting all needed locks at once at the beginning of a query and always

locking the tables in the same order.

@code{InnoDB} type tables automatically acquire their row locks and

@code{BDB} type tables

their page locks during the processing of SQL statements, not at the start

of the transaction.

The locking method MySQL uses for @code{WRITE} locks works as follows:

@itemize @bullet

The table locking code in MySQL is deadlock free.

MySQL uses table locking (instead of row locking or column

locking) on all table types, except @code{BDB} tables, to achieve a very

locking) on all table types, except @code{InnoDB} and @code{BDB} tables,

to achieve a very

high lock speed.  For large tables, table locking is much better than

row locking for most applications, but there are, of course, some

pitfalls.

For @code{InnoDB} and @code{BDB} tables, MySQL only uses table

locking if you explicitely lock the table with @code{LOCK TABLES} or

execute a command that will modify every row in the table, like

@code{ALTER TABLE}.  For these table types we recommend you to not use

@code{LOCK TABLES} at all.

locking if you explicitly lock the table with @code{LOCK TABLES}.

For these table types we recommend you to not use

@code{LOCK TABLES} at all, because @code{InnoDB} uses automatic

row level locking and @code{BDB} uses page level locking to

ensure transaction isolation.

In MySQL Version 3.23.7 and above, you can insert rows into

@code{MyISAM} tables at the same time other threads are reading from the

@code{RESTRICT} and @code{CASCADE} are allowed to make porting easier.

For the moment they don't do anything.

@strong{Note}: @code{DROP TABLE} is not transaction-safe and will

automatically commit any active transactions.

@strong{Note}: @code{DROP TABLE} will

automatically commit current active transaction.

@node CREATE INDEX, DROP INDEX, DROP TABLE, Data Definition

@cindex methods, locking

Currently MySQL only supports table locking for

@code{ISAM}/@code{MyISAM} and @code{HEAP} tables and page level locking

for @code{BDB} tables. @xref{Internal locking}.  With @code{MyISAM}

@code{ISAM}/@code{MyISAM} and @code{HEAP} tables.

@code{InnoDB} tables use row level locking,

and @code{BDB} tables page level locking. @xref{Internal locking}. 

With @code{MyISAM}

tables one can freely mix @code{INSERT} and @code{SELECT} without locks

(@code{Versioning}).

thing to different tables will also helps.

If you get speed problems with the table locks in MySQL, you

may be able to solve these to convert some of your tables to @code{BDB} tables.

@xref{BDB}.

may be able to solve these by converting some of your tables to @code{InnoDB}

or @code{BDB} tables.

@xref{InnoDB}. @xref{BDB}.

The optimisation section in the manual covers a lot of different aspects of

how to tune ones application. @xref{Tips}.