PostgreSQL: Documentation: 13: Chapter 37. Extending SQL

November 21, 2024: PostgreSQL 17.2, 16.6, 15.10, 14.15, 13.18, and 12.22 Released!

Documentation → PostgreSQL 13

Supported Versions: Current (17) / 16 / 15 / 14 / 13

Development Versions: devel

Unsupported versions: 12 / 11 / 10 / 9.6 / 9.5 / 9.4 / 9.3 / 9.2 / 9.1 / 9.0 / 8.4 / 8.3 / 8.2 / 8.1 / 8.0 / 7.4 / 7.3 / 7.2 / 7.1

Chapter 37. Extending SQL
Prev	Up	Part V. Server Programming	Home	Next

Chapter 37. Extending SQL

Table of Contents

37.1. How Extensibility Works

37.2. The PostgreSQL Type System

37.2.1. Base Types
37.2.2. Container Types
37.2.3. Domains
37.2.4. Pseudo-Types
37.2.5. Polymorphic Types

37.3. User-Defined Functions

37.4. User-Defined Procedures

37.5. Query Language (SQL) Functions

37.5.1. Arguments for SQL Functions
37.5.2. SQL Functions on Base Types
37.5.3. SQL Functions on Composite Types
37.5.4. SQL Functions with Output Parameters
37.5.5. SQL Functions with Variable Numbers of Arguments
37.5.6. SQL Functions with Default Values for Arguments
37.5.7. SQL Functions as Table Sources
37.5.8. SQL Functions Returning Sets
37.5.9. SQL Functions Returning TABLE
37.5.10. Polymorphic SQL Functions
37.5.11. SQL Functions with Collations

37.6. Function Overloading

37.7. Function Volatility Categories

37.8. Procedural Language Functions

37.9. Internal Functions

37.10. C-Language Functions

37.10.1. Dynamic Loading
37.10.2. Base Types in C-Language Functions
37.10.3. Version 1 Calling Conventions
37.10.4. Writing Code
37.10.5. Compiling and Linking Dynamically-Loaded Functions
37.10.6. Composite-Type Arguments
37.10.7. Returning Rows (Composite Types)
37.10.8. Returning Sets
37.10.9. Polymorphic Arguments and Return Types
37.10.10. Shared Memory and LWLocks
37.10.11. Using C++ for Extensibility

37.11. Function Optimization Information

37.12. User-Defined Aggregates

37.12.1. Moving-Aggregate Mode
37.12.2. Polymorphic and Variadic Aggregates
37.12.3. Ordered-Set Aggregates
37.12.4. Partial Aggregation
37.12.5. Support Functions for Aggregates

37.13. User-Defined Types

37.13.1. TOAST Considerations

37.14. User-Defined Operators

37.15. Operator Optimization Information

37.15.1. COMMUTATOR
37.15.2. NEGATOR
37.15.3. RESTRICT
37.15.4. JOIN
37.15.5. HASHES
37.15.6. MERGES

37.16. Interfacing Extensions to Indexes

37.16.1. Index Methods and Operator Classes
37.16.2. Index Method Strategies
37.16.3. Index Method Support Routines
37.16.4. An Example
37.16.5. Operator Classes and Operator Families
37.16.6. System Dependencies on Operator Classes
37.16.7. Ordering Operators
37.16.8. Special Features of Operator Classes

37.17. Packaging Related Objects into an Extension

37.17.1. Extension Files
37.17.2. Extension Relocatability
37.17.3. Extension Configuration Tables
37.17.4. Extension Updates
37.17.5. Installing Extensions Using Update Scripts
37.17.6. Security Considerations for Extensions
37.17.7. Extension Example

37.18. Extension Building Infrastructure

In the sections that follow, we will discuss how you can extend the PostgreSQL SQL query language by adding:

functions (starting in Section 37.3)
aggregates (starting in Section 37.12)
data types (starting in Section 37.13)
operators (starting in Section 37.14)
operator classes for indexes (starting in Section 37.16)
packages of related objects (starting in Section 37.17)

Prev	Up	Next
Part V. Server Programming	Home	37.1. How Extensibility Works

Submit correction

If you see anything in the documentation that is not correct, does not match your experience with the particular feature or requires further clarification, please use this form to report a documentation issue.