As data in tables is updated and / or deleted, pockets of empty space can be created, leading to fragmented free space. This free space is wasted space as it is insufficient to hold new data. Moreover, it can impact performance of the database as a higher number of sparsely-populated blocks need to be visited. Oracle 11g introduced online segment… Continue Reading →


Article #3 in my ongoing series covering SQL statistic functions in Oracle Database is now up. The topic is the median: MEDIAN: For When You Don’t Really Mean It Median is useful in typifying a data set when the data might be skewed, or in the presence of extreme outliers. For example, the U.S. Census Bureau reports median household income… Continue Reading →

Application Development, Database Administration, Database Development, Oracle Database, PL/SQL, Uncategorized

Technology is dominated by two types of people: those who understand what they do not manage, and those who manage what they do not understand – Putt’s Law We are always working with data and their datatypes. In the tables we constrain the data by their datatype. For instance, we create a price column of type NUMBER(4,2) telling the database… Continue Reading →

10g, All Things Oracle Full Articles, Database Development, PL/SQL, Troubleshooting, Uncategorized

As I posted on my blog, I just got the good news that I was accepted as an Oracle ACE Director ! This is something that makes me very proud and honors my work, thanks for everyone that supported me. If you are not familiar with the Oracle ACE Program, it is a way for Oracle to acknowledge not only technical skills but… Continue Reading →


In part one of “Generating XML from SQL and PL/SQL“, I explained how to generate XML from SQL. In this second part I’ll show you how you can generate XML from table data in PL/SQL. The datatype to hold XML in PL/SQL or in the database is XMLTYPE. So you can use the generated XML in PL/SQL, store it in… Continue Reading →

All Things Oracle Full Articles, Database Development, Oracle Database, PL/SQL, Uncategorized

In part 1 I explained how to duplicate a single instance database using RMAN. This article will focus on converting the single instance to RAC. 2. Convert Single instance to RAC We have migrated the database successfully from Non-ASM to ASM using RMAN; the database is still running as single instance.  Now we need to convert the single instance database… Continue Reading →

10g, 11g, All Things Oracle Full Articles, Application Development, Database Administration, Oracle Database, Uncategorized

During the management of the Exadata, we have seen numerous incidents ranging from the eviction of the nodes to the hanging cluster and from cooked controllers to bad hard disks. On all the occasions we have been engaged with the My Oracle Support to identify the root cause, which more often than not results in either a known bug or… Continue Reading →

Database Administration, Database Development, Oracle Database, Troubleshooting, Uncategorized