CS-GY 6083: Principles of Database Systems
main
main
  • Introduction
  • DBMS Basics
    • Introduction to DBMS
    • Why use a DBMS instead of a File System?
    • Levels of Abstraction
    • Instances and Schemas
  • Data Models
    • Introduction to Data Models
    • Database Languages
    • Database Design
  • DBMS Internals
    • Introduction to DBMS Internals
    • Storage Manager
    • Query Processor
    • Transaction Management
    • Database Users
    • Database Architecture
  • DBMS History
  • Some Popular Database Systems
  • OLTP, OLAP, and Data Mining
  • Databases vs. Information Retrieval
  • The Entity-Relationship Model - Details
    • Introduction
    • Cardinality Constraints
    • ER Diagram Components
    • ER Diagram to Relational Schema
    • Design Issues
  • The Relational Model - Details
    • Relations
    • Keys
    • Relational Query Languages
      • Relational Algebra
      • Relational Calculus
      • Relative Expressive Power
    • Relational Operators
  • SQL
    • Introduction to SQL
    • Domain Types in SQL
    • DDL Commands
      • Creating a Table
      • Alter and Drop
    • DML Commands
      • Basic Query Structure
      • Select
      • From
      • Where
      • Joins
      • Rename
      • String Operations
      • Ordering
      • Set Operations
      • Group By and Having
      • Nested Subqueries
      • Test for Empty Relations
      • Test for Duplicate Tuples
      • Derived Relations
      • With
      • Database Modification
    • Intermediate SQL
      • Joins Revisited
      • Views
      • Transactions
      • Integrity Constraints
      • More SQL Data Types and Schemas
        • Other Features
      • Authorization
    • Advanced SQL
      • Accessing SQL From a Programming Language
        • ODBC and JDBC
        • Embedded SQL
        • PHP
        • Some Security Issues
      • Accessing Metadata
      • Text Operations
        • Like
        • Contains
      • Cursors
      • Functions and Procedures
        • Procedural Constructs
        • External Language Routines
      • Triggers
      • Ranking
      • Windowing
      • OLAP
Powered by GitBook
On this page

Was this helpful?

  1. SQL
  2. Advanced SQL
  3. Functions and Procedures

External Language Routines

SQL allows us to use procedures and functions written in other languages like C, C++ .

create procedure dept_count_proc(in dept_name varchar(20), out count integer)
language C
external name '/usr/avi/bin/dept_count_proc'
create function dept_count(dept_name varchar(20))
returns integer
language C
external name '/usr/avi/bin/dept_count'

The advantage of using external languages is that they have more efficient implementations of various operations and have more expressive power.

However, the code needed to implement the function must be loaded into the database system and executed in the database system's address space. This involves the risks of accidental database corruption and security issues, such as allowing users unauthorized access to data.

PreviousProcedural ConstructsNextTriggers

Last updated 4 years ago

Was this helpful?