At this level, individuals have a basic understanding of SQL and Oracle databases. They are familiar with data types in Oracle SQL and aware of basic SQL commands like SELECT, INSERT, UPDATE, DELETE. However, their knowledge is mostly theoretical, and they may not be able to apply it practically.

Novices can write simple SELECT statements and understand the use of WHERE clause. They have knowledge of JOIN operations and can use ORDER BY and GROUP BY clauses. They also know how to use basic functions like COUNT(), SUM(), AVG(). They can perform simple tasks but may need guidance for complex operations.

Intermediate users can use subqueries and UNION, INTERSECT, MINUS operators proficiently. They can create and manage tables, understand data constraints, sequences, and synonyms. They can use advanced functions like RANK(), LEAD(), LAG(). They can handle moderately complex tasks independently.

Advanced users are proficient in using PL/SQL and can create and manage views. They understand indexes, triggers, stored procedures, and functions. They can handle exceptions in PL/SQL and understand cursors and collections in PL/SQL. They can handle complex tasks and troubleshoot issues.

Experts are proficient in performance tuning and can use analytic functions. They understand materialized views and partitioning techniques. They can manage large databases and understand advanced security features in Oracle SQL. They can handle highly complex tasks, optimize database performance, and provide solutions to critical issues.