Part II. The SQL Language

   This part describes the use of the SQL language in PostgreSQL. We start
   with describing the general syntax of SQL, then how to create tables,
   how to populate the database, and how to query it. The middle part
   lists the available data types and functions for use in SQL commands.
   Lastly, we address several aspects of importance for tuning a database.

   The information is arranged so that a novice user can follow it from
   start to end and gain a full understanding of the topics without having
   to refer forward too many times. The chapters are intended to be
   self-contained, so that advanced users can read the chapters
   individually as they choose. The information is presented in narrative
   form with topical units. Readers looking for a complete description of
   a particular command are encouraged to review the Part VI.

   Readers should know how to connect to a PostgreSQL database and issue
   SQL commands. Readers that are unfamiliar with these issues are
   encouraged to read Part I first. SQL commands are typically entered
   using the PostgreSQL interactive terminal psql, but other programs that
   have similar functionality can be used as well.

   Table of Contents

   4. SQL Syntax

        4.1. Lexical Structure
        4.2. Value Expressions
        4.3. Calling Functions

   5. Data Definition

        5.1. Table Basics
        5.2. Default Values
        5.3. Identity Columns
        5.4. Generated Columns
        5.5. Constraints
        5.6. System Columns
        5.7. Modifying Tables
        5.8. Privileges
        5.9. Row Security Policies
        5.10. Schemas
        5.11. Inheritance
        5.12. Table Partitioning
        5.13. Foreign Data
        5.14. Other Database Objects
        5.15. Dependency Tracking

   6. Data Manipulation

        6.1. Inserting Data
        6.2. Updating Data
        6.3. Deleting Data
        6.4. Returning Data from Modified Rows

   7. Queries

        7.1. Overview
        7.2. Table Expressions
        7.3. Select Lists
        7.4. Combining Queries (UNION, INTERSECT, EXCEPT)
        7.5. Sorting Rows (ORDER BY)
        7.6. LIMIT and OFFSET
        7.7. VALUES Lists
        7.8. WITH Queries (Common Table Expressions)

   8. Data Types

        8.1. Numeric Types
        8.2. Monetary Types
        8.3. Character Types
        8.4. Binary Data Types
        8.5. Date/Time Types
        8.6. Boolean Type
        8.7. Enumerated Types
        8.8. Geometric Types
        8.9. Network Address Types
        8.10. Bit String Types
        8.11. Text Search Types
        8.12. UUID Type
        8.13. XML Type
        8.14. JSON Types
        8.15. Arrays
        8.16. Composite Types
        8.17. Range Types
        8.18. Domain Types
        8.19. Object Identifier Types
        8.20. pg_lsn Type
        8.21. Pseudo-Types

   9. Functions and Operators

        9.1. Logical Operators
        9.2. Comparison Functions and Operators
        9.3. Mathematical Functions and Operators
        9.4. String Functions and Operators
        9.5. Binary String Functions and Operators
        9.6. Bit String Functions and Operators
        9.7. Pattern Matching
        9.8. Data Type Formatting Functions
        9.9. Date/Time Functions and Operators
        9.10. Enum Support Functions
        9.11. Geometric Functions and Operators
        9.12. Network Address Functions and Operators
        9.13. Text Search Functions and Operators
        9.14. UUID Functions
        9.15. XML Functions
        9.16. JSON Functions and Operators
        9.17. Sequence Manipulation Functions
        9.18. Conditional Expressions
        9.19. Array Functions and Operators
        9.20. Range/Multirange Functions and Operators
        9.21. Aggregate Functions
        9.22. Window Functions
        9.23. Merge Support Functions
        9.24. Subquery Expressions
        9.25. Row and Array Comparisons
        9.26. Set Returning Functions
        9.27. System Information Functions and Operators
        9.28. System Administration Functions
        9.29. Trigger Functions
        9.30. Event Trigger Functions
        9.31. Statistics Information Functions

   10. Type Conversion

        10.1. Overview
        10.2. Operators
        10.3. Functions
        10.4. Value Storage
        10.5. UNION, CASE, and Related Constructs
        10.6. SELECT Output Columns

   11. Indexes

        11.1. Introduction
        11.2. Index Types
        11.3. Multicolumn Indexes
        11.4. Indexes and ORDER BY
        11.5. Combining Multiple Indexes
        11.6. Unique Indexes
        11.7. Indexes on Expressions
        11.8. Partial Indexes
        11.9. Index-Only Scans and Covering Indexes
        11.10. Operator Classes and Operator Families
        11.11. Indexes and Collations
        11.12. Examining Index Usage

   12. Full Text Search

        12.1. Introduction
        12.2. Tables and Indexes
        12.3. Controlling Text Search
        12.4. Additional Features
        12.5. Parsers
        12.6. Dictionaries
        12.7. Configuration Example
        12.8. Testing and Debugging Text Search
        12.9. Preferred Index Types for Text Search
        12.10. psql Support
        12.11. Limitations

   13. Concurrency Control

        13.1. Introduction
        13.2. Transaction Isolation
        13.3. Explicit Locking
        13.4. Data Consistency Checks at the Application Level
        13.5. Serialization Failure Handling
        13.6. Caveats
        13.7. Locking and Indexes

   14. Performance Tips

        14.1. Using EXPLAIN
        14.2. Statistics Used by the Planner
        14.3. Controlling the Planner with Explicit JOIN Clauses
        14.4. Populating a Database
        14.5. Non-Durable Settings

   15. Parallel Query

        15.1. How Parallel Query Works
        15.2. When Can Parallel Query Be Used?
        15.3. Parallel Plans
        15.4. Parallel Safety