• Soportan archivos de gran tamaño (63 bits, archivos de tablas superiores a 4 GB)
en comparación con los que soportaban las ISAM. • Están optimizadas para sistemas operativos de 64 bits.
• Posibilidad de indexar campos BLOB y TEXT.
• Se permiten valores NULL en columnas indexadas.
• Cada tabla guarda un registro que indica si fue cerrada correctamente o no, y al iniciar MySQL existe la opción de indicate that registration is verified, and repair the table if necessary, automatically. This is accomplished by starting MySQL with the option
- myisam-recover
If you find an error, try to repair it quickly sorting the records in the table. If the problem persists, re-create the file containing the table. And if it continues to exist, it tries to repair the records without a writing system.
• Concurrent Inserts (Insert multiple records at once). MERGE
This type of table is used where it is needed to address a number N of MyISAM tables (the same structure and belong the same database, which also should be part of MERGE table) like one.
This could apply if the original MyISAM table is large, and access your content take a considerable amount of time and resources. Obviously, we're talking about a really big table.
Other features:
• can be applied only SELECT, DELETE and UPDATE.
• The table definition is stored in a file. FRM, and the list of MyISAM tables in a file. MRG (here is actually an index of files. MYI used. View MyISAM tables).
• Allow some way to circumvent the size maximum table and the maximum size of a file on a specific operating system.
• We know that if we delete a MyISAM table that is part of the MERGE table, we can not do under the Windows operating system because it does not allow deleting open files, and table, to join the MERGE table is considered open. For the same reason there are drawbacks in applying instructions such as DROP TABLE, ALTER TABLE, DELETE FROM without a WHERE clause, REPAIR TABLE, TRUNCATE TABLE, OPTIMIZE TABLE and ANALYZE TABLE. One way around this is to delete the contents of the MERGE table (using the DELETE statement without a WHERE a MERGE table does not delete the contents MyISAM table but they are removed from the list of components of MERGE table). So consider these tables are not open. When you create a table of this type must be specified (with the UNION statement) the list of associated tables. Here is an example.
CREATE TABLE t1 (a INT AUTO_INCREMENT PRIMARY KEY, message CHAR (20));
CREATE TABLE t2 (a INT AUTO_INCREMENT PRIMARY KEY, message CHAR (20));
INSERT INTO t1 (message) VALUES ('a ");
INSERT INTO t1 (message) VALUES ('two') INSERT INTO t1
(message) VALUES ('three');
INSERT INTO t2 (message) VALUES ('four') INSERT INTO t2
( message) VALUES ("five");
INSERT INTO t2 (message) VALUES ("six");
CREATE TABLE total (a INT AUTO_INCREMENT
PRIMARY KEY,
message CHAR (20)
)
ENGINE = MERGE UNION = (t1 , t2) INSERT_METHOD = LAST;
SELECT * FROM total;
would return something like:
January 1 February 2 March 3
January 4 February 5 March 6
INSERT_METHOD parameter specified in which table will be held on INSERTS, if the top of the list (making INSERT_METHOD = FIRST) or last (putting INSERT_METHOD = LAST). In our case, table t1 is the first and t2 is the last. HEAP
Such tables have a characteristic that makes them different from the rest: are memory tables, are temporary and disappear when the server is closed.
is important to know that this makes them really fast and, unlike a TEMPORARY table, which can only be accessed by the user who creates a HEAP table can be used by different people.
Some other features:
• No support columns of type BLOB or TEXT.
• Do not support AUTO_INCREMENT columns of type.
• Do not allow NULL values \u200b\u200bin columns that have been indexed (before MySQL on the appropriate version to 4.0.2).
• should always specify the maximum number of rows (MAX_ROWS) when you create the table, not to use all available memory. InnoDB We know that these tables, as the BerkeleyDB are TST: This term means Transactions Safe Tables, boards for secure transactions. Tables TST are less rapid rate and hold more memory, but instead offer more security against failure during the consultation.
addition, InnoDB tables have the following characteristics:
• Provide the ability to secure transactions. ACID (Atomicity, Consistency, Separation, Isolation and Durability in English).
• Failover.
• Supports FOREIGN KEY (Foreign Keys). First time there is this in MySQL.
• row level locking.
• Perform backups while the database is running.
• Greater efficiency in processing large volumes of information. • No clues as to create columns of type BLOB or TEXT.
• A table can not have more than 1000 columns.
• Deleting all rows from a table delete them one by one, leading to problems related to speed. Until now truncate tables.
were added in version 4.0 of MySQL.
BerkeleyDB
These tables can be used independently of MySQL: are developed by another company (Sleepycat) and the database manager MySQL provides an interface to work with them as a possibility.
• Supports COMMIT and ROLLBACK operations.
• type is called TST (Transactions Safe Tables). We can see INNODB tables for more information about this topic.
• Typically, to install them to look for a version of MySQL that includes support for such tables, and enable the option at installation time (- with-berkeley dboption *).
• In the file where you saved the data also saves the path to that same file, so you can not change the base directory.
Why would use each one?
As always, the answer depends on what you have to do. The tables are commonly used today are MyISAM, but soon (perhaps very soon) will begin to use INNODB
, especially the ability to create relationships between tables (essential in the relational model) and provide greater regarding the safety benefits in addition to the transactions.
The ISAM
are virtually obsolete (even the company that develops MySQL supports the possibility that in the version 5 no longer available), and others have very specific uses and even compatible with other types: the key is to study the problems that need solving, in each case and see what it is.
phrase 
Many times in our java projects can not do this, as the web framework does not. For these cases there URLRewrite, which allows our url rewriting as we want; eye not only be used for restful url but for any change we would like to make our urls. 
But what son en realidad los procedimientos almacenados? Luego de sumergirnos en este tema veremos que el nombre es plenamente identificatorio y casi explica lo que es un procedimiento almacenado. 
(4) UNSIGNED, 
$ content [] = "x = $ x"; 
According to Gartner, in addition to PCs and Macs, for study also took into account the large corporate computers, called "servers" where IBM, HP and Oracle have more presence. Between server operators proved the most popular Linux. 
wikipedia tells us: 
authentication is to verify that the user is who claims to be. In an EJB system, a user is associated with Secured identity, this is ready to be used by the EJB. When a client invokes a method on an EJB, the server passes the client's identity with the method invocation. When the EJB container receives the invocation validates the user's identity and whether it can invoke the method invoked. 
Session EJB beans are the actions that have, are those with business logic. This type of bean Stateless comes in 2 flavors (does not maintain state on the server) and Stateful (maintains state on the server). You can add a Sigleton Beans, for when we need only one instance of our business object. 
leave the link: 
showFoo public void (Foo foo) {Foo foo2 = new Foo (); 
