All posts under Oracle

Working with hierarchies in Oracle

hierarchies

Hi all! One of the most used database concept is  hierarchies. Why? Basically, any relation that can be categorized as a “Father” – “Son” relationship can take advantage of this concept. Lets us imagine you want to represent the relationship between an employer and an employee. You could probably create two[…]

Read More »

A collection that makes PL/SQL Developer crash!

171-0806064603-nuclear-expolsion

I’ve been struggling for a couple of months , with this very annoying problem. Whenever I issued a query like where table_varchar is a type I use defined like my PL/SQL Developer would always crash ! Today , with a tip from a friend I found the reason ! To[…]

Read More »

Where does Oracle process SQL statements ?

brain-017

Programming,programming,programming…a way a of life.(kind of!)  But how many times do we actually stop to think about what we are doing ? I decided to blog on this, because it is important to always keep in mind some basic concepts Whenever we need to execute a SQL statement, Oracle allocates[…]

Read More »

Oracle SQL curiosity of the day

curiosity

While testing around with user HR from Oracle 11g Database samples, I found curious that : only returns 16 rows when it should return 22 ! This happens because the SQL engine literally interprets NULL as a non-existing value. So any columns with a NULL state province will not display :[…]

Read More »