Artículos IT, información y publicaciones sobre MySQL

Últimas publicaciones destacadas en Dataprix sobre esta temática TIC

How to access from SQL Server to MySQL databases

 

Connect SQL Server to MySQL with linked serverWe could need to access to MySQL from SQL Server.

An easy way to do it is creating a linked server that uses an ODBC connection..

 

Avoiding errors concatenating fields with numerical values in SQL Server

 

concatenate stringsThe operator to concatenate in SQL Server is '+', but this operator is also used to add values.

 

Being the same operator for both, the query analyzer makes a concatenation or a sum based on the type of data fields being treated. If the fields are of 'string' type, the operator concatenate, and if it has numeric fields, two integers, for example, it add the two values.

How to connect to a remote MySQL database

 

 

MySQL has some special features when making a connection from a remote client that if we do not know can complicate access to a MySQL database from a different machine that hosts the database.

With other databases such as Oracle or SQL Server, once that no firewall or anything like that prevents us from the client machine access to the server, using normally data acces from a database user we can 'enter'.

With MySQL, although access to the port, usually 3306, is open, the database can be configured to shut out external connections, and the result is the same as if the port was closed by a firewall:

 

telnet mysql.dataprix.es 3306
Trying 188.166.233.199...
telnet: connect to address 188.166.233.199: Connection refused
telnet: Unable to connect to remote host

 

If you get this result should consult the file /etc/my.cnf, and checking for bind-address variable or skip-networking.

If skip-networking is and is not discussed, edit the file and delete it, or make a comment to have no effect and allow external connections:

 

Pentaho 2.0: Virtual Image

 

From Grupo eGlu, Dario Bernabeu and Mariano García Mattío, we have created a virtual machine (vmware) that contains a fully functional BI solution.

It has the following characteristics:

  • Operating System: Ubuntu 8.10
  • BI Platform: Pentaho 2.0
  • DBMS: MySQL

This demo also has the following modules:

  • Pentaho Data Integration: Through this tool we have designed the transformations and jobs that extract, transform and load the data to populate the Data Warehouse. (Select option 'No catalog')
  • Mondrian Workbench: Through this tool we have created multidimensional schemes.
  • Pentaho Metadata Editor: Through this tool we've created the Business Model.
  • Design Studio: Through this tool we have developed the xactions.
  • Pentaho Report Design: Through this tool we have created an ad hoc report that requests input parameters.

These modules can be accessed through the taskbar side:

Improve MySQL performance by adjusting some parameters

 

MySQL, like most database managers, can easily modify the parameters that control memory sizes engaged in certain tasks, resource utilization, concurrency limits, etc.

Properly adjusting these parameters can be obtained many performance improvements, especially if the server / s of the database is not about resources, and if the SQL optimization can not be improved more.

I've recently made some basic settings in a MySQL database, so I take this opportunity to explain some of the process I followed for those who seek an easy way to make a first optimization of parameters in the database. This is not to say that this is the best way to do just that to me has worked out well;)

The first comment that can be very helpful to look in phpMyAdmin to the sections 'Show information about MySQL runtime' and 'Show MySQL system variables', normally accessible from the home page of the application.

The first displays information and statistics collected and maintained the system since its beginning. Pay special attention to the values of variables that are displayed in red, and the advice provided to the right of these values.

Please refer to the variables used to determine the current values of the parameters that could later be modified to improve performance.

 

Twitter will migrate from MySQL to Cassandra DB

 

Cassandra is an open source database distributed, is one of the noteworthy projects of the Apache Software Foundation and appears to be hitting hard. By being distributed enables high availability, fault tolerance and, above all, a highly scalable without loss of performance.

And were using companies that handle large amounts of data such as Rackspace, Digg, or Facebook, and the list is expanding.

The latest news, coming from a blog interview with Ryan King MyNoSQL is that Twitter is considering migrating their MySQL server clusters Cassandra DB.
 

This is a product presentation, which can be found in the same web Cassandra Project 

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