We have covered Top N queries and Invisible columns in Oracle 12c New Features (Part – 1) In this article, we will learn: Session-Level Sequences Cascading Truncate DDL Logging Identity Columns Multiple Index 3. Session-Level Sequences: In Oracle 12c the CREATE SEQUENCE has a new clause to specify the scope of the sequence – either […]
Category: SQL
Oracle 12c new features (Part – 1)
In this article, we will learn the top Oracle 12c new features for developers. Top N Queries: This is a way of limiting the number of rows returned to the first ‘N’ meeting the relevant criteria. For example you might wish to retrieve the top 10 highest paid employees. Before Oracle 12c there were several […]
Order By clause in Oracle : Must Know
In this article, we will learn what a developer should know about Order by clause in Oracle. When multiple columns/expressions are specified in the ORDER BY clause, the precedence of sorting is left to right. The ORDER BY clause can order in ascending (ASC) or descending (DESC) sequence, or a mix of both. If ASC […]
PseudoColumns in Oracle
In this article, we will learn PseudoColumns in oracle. A pseudocolumn behaves like a table column, but is not actually stored in the table. You can select from pseudocolumns, but you cannot insert, update, or delete their values. A pseudocolumn is also similar to a function without arguments However, functions without arguments typically return the […]
Reset a sequence in Oracle
In oracle, there is no built in commend to reset sequence.So we can look at a work around to reset sequence using a procedure. create or replace procedure reset_sequence(p_seq in varchar2) is l_value number; begin — Select the next value of the sequence execute immediate 'select ' || p_seq || '.nextval from dual' INTO l_value; […]