Some style and consistency cleanups.

@node Nutshell Future features, Nutshell 4.1 development release, Nutshell Other features, MySQL 4.0 In A Nutshell

@subsection Future MySQL 4.0 Features

For the upcoming MySQL Server 4.0 releases (4.0.1, 4.0.2, and onward),

For the upcoming MySQL Server 4.x releases,

expect the following features now still under development:

@itemize @bullet

@end itemize

@menu

* ANSI diff Sub-selects::       Sub-@code{SELECT}s

* ANSI diff Sub-selects::       Sub@code{SELECT}s

* ANSI diff SELECT INTO TABLE::  @code{SELECT INTO TABLE}

* ANSI diff Transactions::      Transactions and Atomic Operations

* ANSI diff Triggers::          Stored Procedures and Triggers

@node ANSI diff Sub-selects, ANSI diff SELECT INTO TABLE, Differences from ANSI, Differences from ANSI

@subsubsection Sub-@code{SELECT}s

@subsubsection Sub@code{SELECT}s

@cindex sub-selects

@cindex sub@code{SELECT}s

MySQL Server currently only supports nested queries of the form

@code{INSERT ... SELECT ...} and @code{REPLACE ... SELECT ...}.

You can, however, use the function @code{IN()} in other contexts.

Sub-selects are scheduled for implementation in Version 4.x.

Subselects are currently being implemented in the 4.1 development tree.

Meanwhile, you can often rewrite the query without a sub-select:

Meanwhile, you can often rewrite the query without a subselect:

@example

SELECT * FROM table1 WHERE id IN (SELECT id FROM table2);

to hold the subquery.  In some cases, however, this option will not

work. The most frequently encountered of these cases arises with

@code{DELETE} statements, for which standard SQL does not support joins

(except in sub-selects).  For this situation there are two options

(except in subselects).  For this situation there are two options

available until subqueries are supported by MySQL Server.

The first option is to use a procedural programming language (such as

The planned update language will be able to handle stored procedures.

Our aim is to have stored procedures implemented in MySQL Server around

version 4.1. We are also looking at triggers.

version 5.0. We are also looking at triggers.

@node ANSI diff Foreign Keys, ANSI diff Views, ANSI diff Triggers, Differences from ANSI

@cindex views

It is planned to implement views in MySQL Server around version 4.1.

It is planned to implement views in MySQL Server around version 5.0.

Views are mostly useful for letting users access a set of relations as one

table (in read-only mode).  Many SQL databases don't allow one to update

* TODO unplanned::              Things We Don't Plan To Do

@end menu

This appendix lists the features that we plan to implement in MySQL Server.

This section lists the features that we plan to implement in MySQL Server.

Everything in this list is approximately in the order it will be done.  If you

want to affect the priority order, please register a license or support us and

The plan is that we in the future will support the full ANSI SQL99

standard, but with a lot of useful extensions. The challenge is to do

this without sacrifying the speed or compromising the code.

this without sacrificing the speed or compromising the code.

@node TODO MySQL 4.0, TODO MySQL 4.1, TODO, TODO

@itemize @bullet

@item

Subqueries.

@code{SELECT id FROM t WHERE grp IN (SELECT grp FROM g WHERE u > 100)}

@example

SELECT id FROM t WHERE grp IN (SELECT grp FROM g WHERE u > 100);

@end example

@item

Foreign keys, including cascading delete.

Foreign keys for @code{MyISAM} tables, including cascading delete.

@item

Fail-safe replication.

@item

also extend the info interface to get the key distribution for each index,

if @code{analyze} is run on all subtables.

@item

@code{RENAME TABLE} on a table used in an active @code{MERGE} table may

corrupt the table.

Resolving the issue of @code{RENAME TABLE} on a table used in an active

@code{MERGE} table possibly corrupting the table.

@item

A faster, smaller embedded MySQL library. (Compatible with the old one.)

A faster, smaller embedded MySQL library (compatible with the old one).

@item

Stable openssl support.  (MySQL 4.0 supports rudimentary, not 100% tested,

support for openssl).

Stable OpenSSL support (MySQL 4.0 supports rudimentary, not 100% tested,

support for OpenSSL).

@item

Add support for sorting on @code{UNICODE}.

@item

@itemize @bullet

@item

Atomic multi-table updates@-e.g., @code{update items,month set

items.price=month.price where items.id=month.id;};

Atomic multi-table updates:

@example

UPDATE items,month SET items.price=month.price

WHERE items.id=month.id;

@end example

@item

Don't allow more than a defined number of threads to run MyISAM recover

at the same time.

Make it possible to specify @code{long_query_time} with a granularity

in microseconds.

@item

Add a configurable prompt to the @code{mysql} command-line client, with

options like database in use, time and date...

@item

Link the @code{myisampack} code into the server.

@item

Port of the MySQL code to QNX.

@item

Use read/write mutex in some places to get more speed.

@item

Full foreign key support. One probably wants to implement a procedural

language first.

Full foreign key support in for @code{MyISAM} tables, probably after

the implementation of stored procedures with triggers.

@item

Simple views (first on one table, later on any expression).

@item

@item

@code{SQL_OPTION MAX_SELECT_TIME=#} to put a time limit on a query.

@item

Make the update log to a database.

Make the update log write to a database.

@item

Negative @code{LIMIT} to retrieve data from the end.

Add to @code{LIMIT} to allow retrieval of data from the end of a result set.

@item

Alarm around client connect/read/write functions.

@item

``Find number, dealer, and price of the most expensive article.''

In ANSI SQL this is easily done with a sub-query:

In ANSI SQL this is easily done with a subquery:

@example

SELECT article, dealer, price

WHERE  price=(SELECT MAX(price) FROM shop)

@end example

In MySQL (which does not yet have sub-selects), just do it in

In MySQL (which does not yet have subselects), just do it in

two steps:

@enumerate

``For each article, find the dealer(s) with the most expensive price.''

In ANSI SQL, I'd do it with a sub-query like this:

In ANSI SQL, I'd do it with a subquery like this:

@example

SELECT article, dealer, price

@uref{http://www.ssh.com/}.  With this, you can get an encrypted TCP/IP

connection between a MySQL server and a MySQL client.

If you are using MySQL 4.0, you can also use internal openssl support.

If you are using MySQL 4.0, you can also use internal OpenSSL support.

@xref{Secure connections}.

To make a MySQL system secure, you should strongly consider the

@node Secure connections,  , Password security, User Account Management

@subsection Using Secure Connections

@cindex openssl

@cindex OpenSSL

@cindex SSL and X509 Basics

@menu

@enumerate

@item

Install the openssl library. We have tested MySQL with openssl 0.9.6.

Install the OpenSSL library. We have tested MySQL with OpenSSL 0.9.6.

@uref{http://www.openssl.org/}.

@item

Configure MySQL with @code{--with-vio --with-openssl}.

@code{mysql.user} table with some new columns. You can do this by

running the @code{mysql_fix_privilege_tables.sh} script.

@item

You can check if a running mysqld server supports @code{openssl} by

You can check if a running mysqld server supports OpenSSL by

examining if @code{SHOW VARIABLES LIKE 'have_openssl'} returns @code{YES}.

@end enumerate

forbidden in ANSI SQL to @code{SELECT} from the same table into which you are

inserting.  (The problem is that the @code{SELECT} possibly would

find records that were inserted earlier during the same run.  When using

sub-select clauses, the situation could easily be very confusing!)

subselect clauses, the situation could easily be very confusing!)

@item

@code{AUTO_INCREMENT} columns work as usual.

@cindex rows, deleting

@cindex tables, deleting rows

As MySQL doesn't yet support sub-selects, nor the use of more than one

As MySQL doesn't yet support subselects, nor the use of more than one

table in the @code{DELETE} statement (prior to Version 4.0), you should

use the following approach to delete rows from 2 related tables: