Oracle Database Concepts

1 [1] Oracle DatabaseConcepts 11g Release 2 ( ) E40540-04 May 2015 Oracle Database Concepts , 11g Release 2 ( ) E40540-04 Copyright 1993, 2015, Oracle and/or its affiliates. All rights Authors: Lance Ashdown, Tom KyteContributors: Drew Adams, David Austin, Vladimir Barriere, Hermann Baer, David Brower, Jonathan Creighton, Bj rn Engsig, Steve Fogel, Bill Habeck, Bill Hodak, Yong Hu, Pat Huey, Vikram Kapoor, Feroz Khan, Jonathan Klein, Sachin Kulkarni, Paul Lane, Adam Lee, Yunrui Li, Bryn Llewellyn, Rich Long, Barb Lundhild, Neil Macnaughton, Vineet Marwah, Mughees Minhas, Sheila Moore, Valarie Moore, Gopal Mulagund, Paul Needham, Gregory Pongracz, John Russell, Vivian Schupmann, Shrikanth Shankar, Cathy Shea, Susan Shepard, Jim Stenoish, Juan Tellez, Lawrence To, Randy Urbano, Badhri Varanasi, Simon Watt, Steve Wertheimer, Daniel WongThis software and related documentation are provided under a license agreement containing restrictions on use and disclosure and are protected by intellectual property laws.

2 Except as expressly permitted in your license agreement or allowed by law, you may not use, copy, reproduce, translate, broadcast, modify, license, transmit, distribute, exhibit, perform, publish, or display any part, in any form, or by any means. Reverse engineering, disassembly, or decompilation of this software, unless required by law for interoperability, is information contained herein is subject to change without notice and is not warranted to be error-free. If you find any errors, please report them to us in this is software or related documentation that is delivered to the Government or anyone licensing it on behalf of the Government, then the following notice is GOVERNMENT END USERS: Oracle programs, including any operating system, integrated software, any programs installed on the hardware, and/or documentation, delivered to Government end users are "commercial computer software" pursuant to the applicable Federal Acquisition Regulation and agency-specific supplemental regulations.

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4 All SPARC trademarks are used under license and are trademarks or registered trademarks of SPARC International, Inc. AMD, Opteron, the AMD logo, and the AMD Opteron logo are trademarks or registered trademarks of Advanced Micro Devices. UNIX is a registered trademark of The Open software or hardware and documentation may provide access to or information about content, products, and services from third parties. Oracle Corporation and its affiliates are not responsible for and expressly disclaim all warranties of any kind with respect to third-party content, products, and services unless otherwise set forth in an applicable agreement between you and Oracle . Oracle Corporation and its affiliates will not be responsible for any loss, costs, or damages incurred due to your access to or use of third-party content, products, or services, except as set forth in an applicable agreement between you and xixDocumentation Accessibility .. xixRelated Documentation .. xxConventions.

5 Xx1 Introduction to Oracle DatabaseAbout Relational 1-1 Database Management System (DBMS) .. 1-1 Relational Model .. 1-2 Relational Database Management System (RDBMS).. 1-2 Brief History of Oracle Database .. 1-3 Schema 1-4 Tables .. 1-4 Indexes .. 1-4 Data 1-5 Structured Query Language (SQL).. 1-5PL/SQL and Java .. 1-5 Transaction 1-6 Transactions .. 1-6 Data Concurrency .. 1-6 Data Consistency .. 1-7 Oracle Database 1-7 Database and Instance .. 1-7 Database Storage Structures .. 1-8 Physical Storage Structures .. 1-9 Logical Storage Structures .. 1-9 Database Instance 1-9 Oracle Database 1-10 Instance Memory Structures .. 1-10 Application and Networking Architecture .. 1-10 Application Architecture .. 1-10 Networking 1-11 Oracle Database Documentation 1-12 Basic Group .. 1-12viIntermediate Group .. 1-12 Advanced 1-13 Part I Oracle Relational Data Structures2 Tables and Table Clusters Introduction to Schema 2-1 Schema Object Types.

6 2-2 Schema Object Storage .. 2-3 Schema Object Dependencies .. 2-4 SYS and SYSTEM Schemas .. 2-5 Sample Schemas .. 2-6 Overview of 2-6 Columns and Rows .. 2-7 Example: CREATE TABLE and ALTER TABLE Statements .. 2-7 Oracle Data Types .. 2-9 Character Data Types .. 2-10 Numeric Data 2-11 Datetime Data Types .. 2-12 Rowid Data 2-13 Format Models and Data 2-14 Integrity Constraints .. 2-14 Object Tables .. 2-15 Temporary Tables .. 2-15 Temporary Table 2-16 Segment Allocation in Temporary Tables .. 2-16 External Tables .. 2-16 External Table 2-17 External Table access 2-17 Table 2-18 Table Organization .. 2-18 Row Storage .. 2-19 Rowids of Row Pieces .. 2-19 Storage of Null 2-19 Table Compression .. 2-19 Basic and Advanced Row 2-19 Hybrid Columnar Compression .. 2-20 Overview of Table 2-22 Overview of Indexed 2-23 Overview of Hash 2-25 Hash Cluster Creation .. 2-25 Hash Cluster Queries.

7 2-26 Hash Cluster Variations .. 2-26 Hash Cluster Storage .. 2-27vii 3 Indexes and Index-Organized Tables Overview of 3-1 Index Characteristics .. 3-2 Keys and 3-3 Composite 3-3 Unique and Nonunique 3-4 Types of 3-4B-Tree Indexes .. 3-5 Branch Blocks and Leaf 3-5 Index Scans .. 3-6 Reverse Key 3-11 Ascending and Descending Indexes .. 3-11 Key Compression .. 3-12 Bitmap Indexes .. 3-13 Bitmap Indexes on a Single 3-14 Bitmap Join Indexes .. 3-15 Bitmap Storage Structure .. 3-17 Function-Based Indexes .. 3-17 Uses of Function-Based Indexes .. 3-18 Optimization with Function-Based Indexes .. 3-19 Application Domain 3-19 Index Storage .. 3-20 Overview of Index-Organized 3-20 Index-Organized Table 3-21 Index-Organized Tables with Row Overflow Area .. 3-23 Secondary Indexes on Index-Organized Tables .. 3-23 Logical Rowids and Physical Guesses .. 3-24 Bitmap Indexes on Index-Organized 3-254 Partitions, Views, and Other Schema Objects Overview of 4-1 Partition Characteristics.

8 4-2 Partition Key .. 4-2 Partitioning Strategies .. 4-2 Partitioned Tables .. 4-7 Partitioned Indexes .. 4-7 Local Partitioned Indexes .. 4-8 Global Partitioned Indexes .. 4-10 Partitioned Index-Organized Tables .. 4-12 Overview of 4-12 Characteristics of Views .. 4-13 Data Manipulation in Views .. 4-13 How Data Is Accessed in Views .. 4-14 Updatable Join Views .. 4-15 Object Views .. 4-16 Overview of Materialized 4-16viiiCharacteristics of Materialized 4-17 Refresh Methods for Materialized Views .. 4-18 Query 4-19 Overview of 4-20 Sequence Characteristics .. 4-20 Concurrent access to 4-20 Overview of 4-21 Hierarchical Structure of a 4-21 Creation of 4-21 Overview of 4-225 Data IntegrityIntroduction to Data 5-1 Techniques for Guaranteeing Data Integrity .. 5-1 Advantages of Integrity Constraints .. 5-1 Types of Integrity 5-2 NOT NULL Integrity 5-3 Unique Constraints .. 5-3 Primary Key 5-5 Foreign Key 5-6 Self-Referential Integrity 5-7 Nulls and Foreign 5-8 Parent Key Modifications and Foreign Keys.

9 5-8 Indexes and Foreign 5-9 Check Constraints .. 5-10 States of Integrity 5-10 Checks for Modified and Existing Data .. 5-10 Deferrable 5-11 Nondeferrable Constraints .. 5-11 Deferrable Constraints .. 5-11 Examples of Constraint Checking .. 5-12 Insertion of a Value in a Foreign Key Column When No Parent Key Value 5-12An Update of All Foreign Key and Parent Key 5-136 Data Dictionary and Dynamic Performance ViewsOverview of the Data 6-1 Contents of the Data Dictionary .. 6-2 Views with the Prefix 6-3 Views with the Prefix ALL_ .. 6-3 Views with the Prefix USER_ .. 6-4 The DUAL Table .. 6-4 Storage of the Data Dictionary .. 6-4 How Oracle Database Uses the Data Dictionary .. 6-4 Public Synonyms for Data Dictionary Views .. 6-5 Cache the Data Dictionary for Fast 6-5 Other Programs and the Data Dictionary .. 6-5 Overview of the Dynamic Performance 6-5ix Contents of the Dynamic Performance Views .. 6-6 Storage of the Dynamic Performance 6-6 Database Object 6-6 Part II Oracle Data Access7 SQLI ntroduction to 7-1 SQL Data 7-1 SQL Standards.

10 7-2 Overview of SQL 7-3 Data Definition Language (DDL) Statements .. 7-3 Data Manipulation Language (DML) Statements .. 7-4 SELECT Statements .. 7-6 Subqueries and Implicit Queries .. 7-7 Transaction Control Statements .. 7-8 Session Control 7-8 System Control 7-9 Embedded SQL Statements .. 7-9 Overview of the 7-10 Use of the 7-10 Optimizer 7-11 Query Transformer .. 7-11 Estimator .. 7-12 Plan 7-12 access Paths .. 7-12 Optimizer Statistics .. 7-13 Optimizer 7-14 Overview of SQL 7-15 Stages of SQL Processing .. 7-15 SQL Parsing .. 7-16 SQL Optimization .. 7-19 SQL Row Source Generation .. 7-19 SQL Execution .. 7-20 How Oracle Database Processes DML .. 7-22 Read Consistency .. 7-22 Data 7-22 How Oracle Database Processes 7-238 Server-Side Programming: PL/SQL and JavaIntroduction to Server-Side 8-1 Overview of 8-2PL/SQL Subprograms .. 8-3 Advantages of PL/SQL Subprograms .. 8-3 Creation of PL/SQL 8-4xExecution of PL/SQL Subprograms.