🚀 go-pugleaf

Tal d�a Tue, 08 Feb 2000 16:37:00 GMT,
Toni M�rtir <techni-web@nospampala.com> nos relat�:

>> Comienza el juego...
>
>No conozco mysql pero esto es impresionante:
>
>> mysql> select count(*) from archivos;
>> +----------+
>> | count(*) |
>> +----------+
>> |   382219 |
>> +----------+
>> 1 row in set (0.06 sec)
>>

El qu� es impresionante, �el n�mero de registros o la velocidad con la que
los cuenta?

Escrib� la orden 'select count(*)' s�lo para decir: "tenemos una tabla con
N registros".
Y si el motor tarda 0.06 segundos, es tan s�lo porque NO los cuenta
secuencialmente (por favor !!!), sino que lo "calcula" accediendo a un dato
fijo, en alg�n lugar de la base de datos.

Si lo "�impresionante?" no era el tiempo para esta "query", sino para la que
remit�a a continuaci�n; la "query" de verdad.

>
>- Soporta transacciones?

NO. Pero...

[/usr/doc/MySQL-3.23.8-alpha/manual_toc.html]

  5.4.3 Transactions
               
   Transactions are not supported. MySQL shortly will support atomic
   operations, which are like transactions without rollback. With atomic
   operations, you can execute a group of INSERT/SELECT/whatever commands
   and be guaranteed that no other thread will interfere. In this
   context, you won't usually need rollback. Currently, you can prevent
   interference from other threads by using the LOCK TABLES and UNLOCK
   TABLES commands. See section 7.24 LOCK TABLES/UNLOCK TABLES syntax.
              
> Stored Procedures? Triggers?

S� y No.

[/usr/doc/MySQL-3.23.8-alpha/manual_toc.html]

  5.4.4 Stored procedures and triggers

   [...]
   The planned update language will be able to handle stored procedures,
   but without triggers. Triggers usually slow down everything, even
   queries for which they are not needed.

   To see when MySQL might get stored procedures, see section F List of
   things we want to add to MySQL in the future (The TODO).


> Referential Integrity?

S�, pero no es funcional. Es decir, No.

[/usr/doc/MySQL-3.23.8-alpha/manual_toc.html]

   The FOREIGN KEY syntax in MySQL exists only for compatibility with
   other SQL vendors' CREATE TABLE commands; it doesn't do anything. The
   FOREIGN KEY syntax without ON DELETE ... is mostly used for
   documentation purposes.

   [...]

    5.4.5.1 Reasons NOT to use foreign keys
               
   There are so many problems with FOREIGN KEYs that we don't know where
   to start:

   [... m�s o menos dice que dificulta la implementaci�n
    y decrementa la velocidad en los INSERT/UPDATE ...]

   The only nice aspect of FOREIGN KEY is that it gives ODBC and some
   other client programs the ability to see how a table is connected and
   to use this to show connection diagrams and to help in building
   applicatons.

   
>O se trata solo de un juego.

Un juego... �por qu�?

Saludos.


P.D. Para m�s info: http://www.mysql.com