manual.texi misc small cleanups

automatically add the @code{UNSIGNED} attribute to the column.

@strong{Warning:} You should be aware that when you use subtraction

between integers values where one is of type @code{UNSIGNED}, the result

between integer values where one is of type @code{UNSIGNED}, the result

will be unsigned! @xref{Cast Functions}.

@table @code

If you issue a @code{DELETE} with no @code{WHERE} clause, all rows are

deleted.  If you do this in @code{AUTOCOMMIT} mode, this works as

@code{TRUNCATE}. @xref{TRUNCATE}.  In MySQL 3.23 @code{DELETE} without a

@code{WHERE} clause will return zero as the number of affected records.

@code{TRUNCATE}. @xref{TRUNCATE, , @code{TRUNCATE}}.  In MySQL 3.23,

@code{DELETE} without a @code{WHERE} clause will return zero as the number

of affected records.

If you really want to know how many records are deleted when you are deleting

all rows, and are willing to suffer a speed penalty, you can use a

@code{DELETE} is delayed until no other clients are reading from the table.

If you specify the word @code{QUICK} then the table handler will not

merge index leafs during delete, which may speed up certain kind of

merge index leaves during delete, which may speed up certain kind of

deletes.

In MyISAM tables deleted records are maintained in a linked list and

In @code{MyISAM} tables, deleted records are maintained in a linked list and

subsequent @code{INSERT} operations reuse old record positions. To

reclaim unused space and reduce file sizes, use the @code{OPTIMIZE

TABLE} statement or the @code{myisamchk} utility to reorganise tables.

@code{OPTIMIZE TABLE} is easier, but @code{myisamchk} is faster.  See

@ref{OPTIMIZE TABLE, , @code{OPTIMIZE TABLE}} and @ref{Optimisation}.

The first multi table delete format is supported starting from MySQL 4.0.0.

The second multi table delete format is supported starting from MySQL 4.0.2.

The first multi-table delete format is supported starting from MySQL 4.0.0.

The second multi-table delete format is supported starting from MySQL 4.0.2.

The idea is that only matching rows from the tables listed

@strong{before} the @code{FROM} or before the @code{USING} clause are

In the above case we delete matching rows just from tables @code{t1} and

@code{t2}.

@code{ORDER BY} and using multiple tables in the DELETE is supported in

MySQL 4.0.

@code{ORDER BY} and using multiple tables in the @code{DELETE} is supported

in MySQL 4.0.

If an @code{ORDER BY} clause is used, the rows will be deleted in that order.

This is really only useful in conjunction with @code{LIMIT}.  For example:

Fixed bug that sometimes appeared when fulltext search was used

with ``const'' tables.

@item

Fixed wrong error value when doing a @code{SELECT} with an empty HEAP table.

Fixed incorrect error value when doing a @code{SELECT} with an empty HEAP table.

@item

Use @code{ORDER BY column DESC} now sorts @code{NULL} values first.

@item

Fixed bug in @code{WHERE key_name='constant' ORDER BY key_name DESC}.

@item

Fixed bug in @code{SELECT DISTINCT ... ORDER BY DESC} optimization.

Fixed bug in @code{SELECT DISTINCT ... ORDER BY DESC} optimisation.

@item

Fixed bug in @code{... HAVING 'GROUP_FUNCTION'(xxx) IS [NOT] NULL}.

@item

@item

Allow numeric user id to @code{mysqld --user=#}.

@item

Fixed a bug where @code{SQL_CALC_ROWS} returned a wrong value when used

Fixed a bug where @code{SQL_CALC_ROWS} returned an incorrect value when used

with one table and @code{ORDER BY} and with InnoDB tables.

@item

Fixed that @code{SELECT 0 LIMIT 0} doesn't hang thread.

Don't use table scan with BerkeleyDB and InnoDB tables when we can use

an index that covers the whole row.

@item

Optimized InnoDB sort-buffer handling to take less memory.

Optimised InnoDB sort-buffer handling to take less memory.

@item

Fixed bug in multi table @code{DELETE} and InnoDB tables.

Fixed bug in multi-table @code{DELETE} and InnoDB tables.

@item

Fixed problem with @code{TRUNCATE} and InnoDB that gave the error

Fixed problem with @code{TRUNCATE} and InnoDB that produced the error

@code{Can't execute the given command because you have active locked

tables or an active transaction}.

@item

@item

Changed to use @code{autoconf} 2.52 (from @code{autoconf} 2.13).

@item

Fixed optimization problem where the MySQL Server was in ``preparing'' state

Fixed optimisation problem where the MySQL Server was in ``preparing'' state

for a long time when selecting from an empty table which had contained

a lot of rows.

@item

improves performance a bit when referring to another table from a

@code{const} table.

@item

First pre-version of multi table @code{UPDATE}s.

First pre-version of multi-table @code{UPDATE} statement.

@item

Fixed bug in multi table @code{DELETE}.

Fixed bug in multi-table @code{DELETE}.

@item

Fixed bug in @code{SELECT CONCAT(argument-list) ... GROUP BY 1}.

@item

@item

Fixed shutdown problem on HP-UX.

@item

Added functions @code{des_encrypt()} and @code{des_decrypt()}.

Added functions @code{DES_ENCRYPT()} and @code{DES_DECRYPT()}.

@item

Added statement @code{FLUSH DES_KEY_FILE}.

@item

@code{LOCATE()} and @code{INSTR()} are now case sensitive if either

argument is a binary string.

@item

Changed @code{RAND()} initialization so that @code{RAND(N)} and

Changed @code{RAND()} initialisation so that @code{RAND(N)} and

@code{RAND(N+1)} are more distinct.

@item

Fixed core dump bug in @code{UPDATE ... ORDER BY}.

thread doing an @code{ALTER TABLE} on the same table. Before that,

mysqld could crash with an assertion failure in row0row.c, line 474.

@item

Tuned the InnoDB SQL optimizer to favor more often index searches

Tuned the InnoDB SQL optimiser to favor more often index searches

over table scans.

@item

Fixed a performance problem with InnoDB tables when several large SELECT

@item

If MySQL binlogging is used, InnoDB now prints after crash recovery the

latest MySQL binlog name and the offset InnoDB was able to recover

to. This is useful, for example, when resynchronizing a master and a

to. This is useful, for example, when resynchronising a master and a

slave database in replication.

@item

Added better error messages to help in installation problems of InnoDB tables.

than 4 GB on those operating systems which have big files.

@item

@code{InnoDB} calculates better table cardinality estimates for the

MySQL optimizer.

MySQL optimiser.

@item

Accent characters in the default character set latin1 are ordered

according to the MySQL ordering.