1Z0-771

The Oracle 1Z0-771 exam, "Oracle Database SQL Expert," focuses on demonstrating mastery of advanced SQL techniques within the Oracle Database environment. The main points covered comprehensively include:

• Advanced SQL Queries: This is the core of the exam. Expect questions on complex queries involving:

  • Subqueries: Correlated subqueries, nested subqueries, inline views.
  • Joins: Inner, outer (left, right, full), self-joins, using various join conditions.
  • Set Operators: UNION, UNION ALL, INTERSECT, MINUS.
  • Analytic Functions: ROW_NUMBER, RANK, DENSE_RANK, LAG, LEAD, NTILE, etc., understanding their application for data ranking and analysis.
  • Hierarchical Queries: Using CONNECT BY and START WITH to traverse hierarchical data structures.
  • Regular Expressions: Using regular expressions for pattern matching in strings.
  • Conditional Logic within SQL: CASE statements, DECODE function.
  • Aggregate Functions: SUM, AVG, COUNT, MIN, MAX, along with grouping and having clauses.

• Data Manipulation: Not just querying, but understanding how to efficiently manipulate data using:

  • DML Statements: INSERT, UPDATE, DELETE, MERGE. Understanding the implications of each command, including transactional aspects.

• Data Definition: While less emphasized than Data Manipulation and querying, understanding DDL (Data Definition Language) is still relevant:

  • Table creation and modification: Understanding constraints (primary key, foreign key, unique, check, not null), indexes, and data types.

• Data Optimization & Performance: This is a crucial aspect:

  • Understanding execution plans: Basic knowledge of how the Oracle optimizer works and how to interpret execution plans (though not necessarily tuning them in-depth).
  • Index usage: Understanding when and why indexes are beneficial and their impact on performance.
  • Query optimization techniques: General strategies for writing efficient SQL (avoiding full table scans, using appropriate indexes, etc.).

• PL/SQL Fundamentals (Limited): While 1Z0-771 focuses primarily on SQL, a basic understanding of PL/SQL constructs might be needed for certain questions. This will usually be limited to simple PL/SQL blocks within SQL contexts, not extensive procedural programming.

In short: The exam tests your ability to write efficient, complex SQL queries to retrieve, manipulate, and manage data within an Oracle database environment. Focus on mastering the advanced SQL features listed above, along with an understanding of query optimization and database fundamentals. Don't neglect the practical application—the more queries you write and debug, the better prepared you will be.