Do I need to visit college to learn SPSS?


One of the largest useful resources today, most specially for those students who take topics in statistics, is the Record Package for Social Sciences or simply SPSS. SPSS is essentially a software specifically used to handle data from any types of researches such as dissertation and dissertations. Merely so you know, data examination is equally significant as data assortment and interpretation. Meanwhile, analyzing the information can be much more critical for with only one mistake about it can totally ruin the outcome of the specific research.

Cloud and public sectors


If all patients of a metropolitan region such as Barcelona or Madrid or London, or a region like Languedoc Roussillon or Andalusia, had introduced with their medical records digitalized, or even better with Relational databases with SQL for example, which supports many data with many records hosted on servers accessible remotely on "Cloud computing", it would allow health physicians to access data from any PC or "SmartPhone" with an interface SW, through the pick lists that are very intuitive and user Friendly. In addition have an internal Chatter (like salesfoce has), allowing asynchronous communication for consultation among several specialists to achieve a flexible and rapid diagnosis.

Export data from a SQL Server table


To import and export data from SQL Server,  Microsoft provides the tool bpc, which operates by command line. Although it would be appreciated if SQL Server Management Studio would provide some

Differences between Oracle, SQL Server, DB2, MySQL and other ..


The operation of databases from different manufacturers is similar, but there are many differences between them, even at level of SQL syntax.

For example, if you knows Oracle, and one day you have to do a date conversion with MySQL, you will wonder the following:

- How to do a TO_DATE () / TO_CHAR () with MySQL? 

I open this blog entry to discuss different ways of doing things with each database type. 

Here I link the SQL Tips Bristle Software , which explains quite well how to do some things with MySQL, Oracle and SQL Server, and I find especially useful the chapter on differences between Oracle and SQL Server

The Oracle listener


In order to access to the same database where are you working outside the database server you must activate the service called listener, it has to be listening.

It can happens that the database is properly raised and can not connect from other servers, which are also set correctly (correct TNSNAMES, etc.).. 

In these cases could be that the listener has a problem, or simply has not been initiated.

To Check the status, start or stop it is very simple. Just open a command line session (console terminal, etc..) with the user that has installed the database, and run the lsnrctl command with the following parameters:

  • Check your state:
      > lsnrctl status

  • Stop the listener:
      > lsnrctl stop

  • Start the listener:
      > lsnrctl start

Keep in mind that when you stop the listener, the connections that are already in the database won't be closed, so a short stop is not very traumatic, only connections trying to enter while the listener is stopped are rejected, should not affect anyone who already has an opened session.

Login with SQLPlus as a DBA without entering password


If you have the system user who installed the database you can enter SQL Plus as DBA user, without entering a password as follows:

1. Enters the system with this user. 
2. From the command line, go into SQLPlus typing:

> sqlplus "/as sysdba"

If you need to enter using this way because you forgot the password of a user, you can easily change it: 

SQL> alter user user_name identified by new_password;

It can be more than one Database installed on the server, so you have to validate that the environment variables of the Oracle's user are pointing to your database.

For verifying that you has login into the correct database you can execute this statement: 

SQL> select name from v$database; 



Suppose we want to update in our ORACLE database the costs fields of the fact table FAC_TABLE with the unit cost of our table COSTS.

We can do this in two ways:

1. (Slow, but valid for a few data or to sporadic uses)

update FAC_TABLE ft  set UNIT_COST = (select distinct UNIT_COST from COSTS ct  where (ft.id_article = ct.id_article);

2. (The best way is this, and the performance is ideal if you have constraints)

UPDATE ( SELECT ft.UNIT_COST AS old_cost,  ct.UNIT_COST AS new_cost FROM FAC_TABLE ft  INNER JOIN COSTS ct ON ft.id_article ct = ct.id_article) )  SET old_cost = new_cost;

To the proper functionality of this second option you need a UNIQUE or PRIMARY KEY constraint on ct.id_articulo. 
If you don't have this constraint, you can use the hint / * + BYPASS_UJVC * / after the word UPDATE (Bypass update join view constraint).

The performance increase if we have the constraint but even without it, the second option should run quite faster than the first option.


Remote access using Oracle DBLINK


The easiest way to access from an Oracle database objects from another Oracle database is using a DBLINK (being the easiest does not mean that it is always the most desirable, the abuse of DBLINKS can create many problems, both of performance and safety)

To do this it's necessary a user with CREATE DATABASE LINK privilege, and create a DBLINK in the source database (A) by a simple statement such as:

Create database link LNK_from_A_to_B connect to USER identified by PASSWORD USING 'B'; 

'LNK_from_A_to_B' is the name of the link, 'USER' and 'PASSWORD' are the IDs of the user who will use the link to connect, which will inherit the permissions of all access through the link, and B is the name of the database's instance.

Using the DBLINK we can connect to the objects with the remote database's permissions that user has been provided in the creation statement.

To reference an object from the remote database should indicate the name of the object, concatenated with the character '@' and the name that we had given to the DBLINK.


select * from TABLA@LNK_from_A_to_B 

How to connect from Oracle SQL Developer with a remote SQL Server


The digital story of the Nativity


Great video showing through the use of social media an original story of Jesus' birth at Christmas.

Besides being fun, it's a good way to make a quick tour of the main features of Facebook, Twitter, YouTube, Google, Wikipedia, Google Maps, GMail, Foursquare or Amazon ...

How times change:)

Syndicate content