Oracle Tutorials, Tips & Tricks

Oracle 11G new feature: Virtual Column

Oracle 11g introduced the concept of ‘Virtual Column’ within a table. Virtual Columns are similar to normal table’s columns but with the following differences: They are defined by an expression. The result of evaluation...

Row Data Multiplication in Oracle

Row Data Multiplication in Oracle

Aggregate functions return a single result row based on a group of rows. This differentiates them from Single-Row functions which act on each row. These functions are extensively used with the GROUP BY clause...

Generating Random Data in Oracle

Most of the times, production data is not available in development environments. Here, I would like to share a single sql command which can generate random data. But before that, let’s address another issue...

Deleting Duplicate Rows in Oracle

Deleting Duplicate Rows in Oracle

Deleting duplicate rows from tables is one of the common task oracle developers come across. The data might get duplicated because of missing primary/unique key on the table or batch file getting loaded multiple...

Invisible Indexes in Oracle 11g

Invisible Indexes in Oracle 11g

The effective usage of an index is always a big question. There are instances in production environments, where an index may help the performance of just a single query, while it can degrade the...

Oracle Data Compression

Oracle Data Compression

As the data grows in relational databases (new business requirements, managing audit data etc), the cost associated with the disk systems to store that data and the resources required to manage them becomes vital....