Chapter 36. Extending SQL
Table of Contents
- 36.1. How Extensibility Works- 36.2. The Postgres Pro Type System
- 36.3. User-defined Functions- 36.4. Query Language (SQL) Functions
- 36.4.1. Arguments for SQL Functions- 36.4.2. SQL Functions on Base Types
- 36.4.3. SQL Functions on Composite Types
- 36.4.4. SQL Functions with Output Parameters
- 36.4.5. SQL Functions with Variable Numbers of Arguments
- 36.4.6. SQL Functions with Default Values for Arguments
- 36.4.7. SQL Functions as Table Sources
- 36.4.8. SQL Functions Returning Sets
- 36.4.9. SQL Functions Returning
TABLE
- 36.4.10. Polymorphic SQL Functions
- 36.4.11. SQL Functions with Collations
- 36.4.2. SQL Functions on Base Types
 
- 36.4.1. Arguments for SQL Functions
- 36.5. Function Overloading- 36.6. Function Volatility Categories
- 36.7. Procedural Language Functions
- 36.8. Internal Functions
- 36.9. C-Language Functions
- 36.6. Function Volatility Categories
- 36.9.1. Dynamic Loading- 36.9.2. Base Types in C-Language Functions
- 36.9.3. Version 1 Calling Conventions
- 36.9.4. Writing Code
- 36.9.5. Compiling and Linking Dynamically-loaded Functions
- 36.9.6. Composite-type Arguments
- 36.9.7. Returning Rows (Composite Types)
- 36.9.8. Returning Sets
- 36.9.9. Polymorphic Arguments and Return Types
- 36.9.10. Transform Functions
- 36.9.11. Shared Memory and LWLocks
- 36.9.12. Using C++ for Extensibility
- 36.9.2. Base Types in C-Language Functions
 
- 36.9.1. Dynamic Loading
- 36.10. User-defined Aggregates
- 36.11. User-defined Types- 36.12. User-defined Operators
- 36.13. Operator Optimization Information
- 36.12. User-defined Operators
- 36.14. Interfacing Extensions To Indexes
- 36.15. Packaging Related Objects into an Extension
- 36.16. Extension Building Infrastructure
In the sections that follow, we will discuss how you can extend the Postgres Pro SQL query language by adding:
- functions (starting in Section 36.3) 
- aggregates (starting in Section 36.10) 
- data types (starting in Section 36.11) 
- operators (starting in Section 36.12) 
- operator classes for indexes (starting in Section 36.14) 
- packages of related objects (starting in Section 36.15) 

