The MySQL 4.1 features listed in this section already are implemented. A few other MySQL 4.1 features are still planned; see section 1.6.1 New Features Planned for 4.1.

Most new features being coded are or will be available in MySQL 5.0. See section 1.6.2 New Features Planned for 5.0.

Support for subqueries and derived tables

• A ``subquery'' is a SELECT statement nested within another statement. A ``derived table'' (an unnamed view) is a subquery in the FROM clause of another statement. See section 14.1.8 Subquery Syntax.

Speed enhancements

• Faster binary client/server protocol with support for prepared statements and parameter binding. See section 21.2.4 C API Prepared Statements.
• BTREE indexing is now supported for HEAP tables, significantly improving response time for non-exact searches.

New functionality

• CREATE TABLE tbl_name2 LIKE tbl_name1 allows you to create, with a single statement, a new table with a structure exactly like that of an existing table.
• The MyISAM storage engine now supports OpenGIS spatial types for storing geographical data. See section 19 Spatial Extensions in MySQL.
• Replication can be done over SSL connections.

Standards compliance, portability, and migration

• The new client/server protocol adds the ability to pass multiple warnings to the client, rather than only a single result. This makes it much easier to track problems that occur in operations such as bulk data loading.
• SHOW WARNINGS shows warnings for the last command. See section 14.5.3.20 SHOW WARNINGS Syntax.

Internationalization

• To support applications that require the use of local languages, the MySQL software now offers extensive Unicode support through the utf8 and ucs2 character sets.
• Character sets can now be defined per column, table, and database. This allows for a high degree of flexibility in application design, particularly for multi-language Web sites.
• For documentation for this improved character set support, see section 11 Character Set Support.

Usability enhancements

• In response to popular demand, we have added a server-based HELP command that can be used to get help information for SQL statements. The advantage of having this information on the server side is that the information is always applicable to the particular server version that you actually are using. Because this information is available by issuing an SQL statement, any client can be written to access it. For example, the help command of the mysql command-line client has been modified to have this capability.
• In the new client/server protocol, multiple statements can be issued with a single call. See section 21.2.8 C API Handling of Multiple Query Execution.
• The new client/server protocol also supports returning multiple result sets. This might occur as a result of sending multiple statements, for example.
• A new INSERT ... ON DUPLICATE KEY UPDATE ... syntax has been implemented. This allows you to UPDATE an existing row if the INSERT would have caused a duplicate in a PRIMARY or UNIQUE index. See section 14.1.4 INSERT Syntax.
• A new aggregate function, GROUP_CONCAT() adds the extremely useful capability of concatenating column values from grouped rows into a single result string. See section 13.9 Functions and Modifiers for Use with GROUP BY Clauses.