Functionality added or changed:
This is the first public alpha release of the current MySQL 5.1 development branch, providing an insight to upcoming features. Although some of these are still under heavy development, this release includes the following new features and changes (in comparison to the current MySQL 5.0 production release):
Partitioning: allows distributing portions of individual tables across a filesystem, according to rules which can be set when the table is created. In effect, different portions of a table are stored as separate tables in different locations, but from the user point of view, the partitioned table is still a single table. See Kapitel 17, Partitionierung, for further information on this functionality. (Author: Mikael Ronström)
Plugin API: MySQL 5.1 adds support for a very flexible plugin API that enables loading and unloading of various components at runtime, without restarting the server. Although the work on this is not finished yet, plugin full-text parsers are a first step in this direction. This allows users to implement their own input filter on the indexed text, enabling full-text search capability on arbitrary data such as PDF files or other document formats. A pre-parser full-text plugin performs the actual parsing and extraction of the text and hands it over to the built-in MySQL full-text search. (Author: Sergey Vojtovich)
The plugin API requires the mysql.plugin
table. When upgrading from an older version of MySQL, you
should run the mysql_fix_privilege_tables
command to create this table. See
Abschnitt 5.6, „mysql_fix_privilege_tables — Upgrade von MySQL-Systemtabellen“.
Incompatible change: Plugins
are installed in the directory named by the
plugin_dir
system variable. This variable
also controls the location from which the server loads
user-defined functions (UDFs), which is a change from earlier
versions of MySQL. That is, all UDF library files now must be
installed in the plugin directory. When upgrading from an
older version of MySQL, you must migrate your UDF files to the
plugin directory.
The Instance Manager (IM) now has some additional functionality:
SHOW
provides a listing of all log files
used by the instance. (Author: Petr Chardin)
instance_name
LOG FILES
SHOW
retrieves a
part of the specified log file. (Author: Petr Chardin)
instance_name
LOG {ERROR | SLOW | GENERAL}
size
SET
sets an option to the specified value and writes it to
the config file See Abschnitt 5.5, „mysqlmanager — Der MySQL Instance Manager“,
for more details on these new commands. (Author: Petr
Chardin)
instance_name
.
option_name
=option_value
The performance of boolean full-text searches (using the „+“ Operator) has been improved. See Abschnitt 12.7, „MySQL-Volltextsuche“, for more details about full-text searching. (Author: Sergey Vojtovich)
VARCHAR
fields used in MySQL Cluster tables
are now variable-sized; that is, they now only allocate as
much space as required to store the data. Previously, a
VARCHAR(
column allocated n+2 bytes (aligned to 4 bytes), regardless if
the actual inserted value required that much space. (In other
words, a n
)VARCHAR
column always required the
same, fixed, amount of storage as a CHAR
column of the same size.)
Renamed the table_cache
system variable to
table_open_cache
. Any scripts that refer to
table_cache
should be updated to use the
new name.
Added the table_definition_cache
system
variable. If you use a large number of tables, you can create
a large table definition cache to speed up opening of tables.
The table definition cache takes less space and does not use
file descriptors, unlike the normal table cache.
Bugs fixed:
Set functions could not be aggregated in outer subqueries. (Bug#12762)
Dies ist eine Übersetzung des MySQL-Referenzhandbuchs, das sich auf dev.mysql.com befindet. Das ursprüngliche Referenzhandbuch ist auf Englisch, und diese Übersetzung ist nicht notwendigerweise so aktuell wie die englische Ausgabe. Das vorliegende deutschsprachige Handbuch behandelt MySQL bis zur Version 5.1.