Скачать или смотреть How to Identify User-Defined Types Used in PostgreSQL Procedures and Functions

Discover how to effectively find user-defined types and domains in PostgreSQL stored procedures and functions, and learn about the challenges involved in this process.
---
This video is based on the question https://stackoverflow.com/q/66277632/ asked by the user 'Mano' ( https://stackoverflow.com/u/5944884/ ) and on the answer https://stackoverflow.com/a/66278219/ provided by the user 'Laurenz Albe' ( https://stackoverflow.com/u/6464308/ ) at 'Stack Overflow' website. Thanks to these great users and Stackexchange community for their contributions.

Visit these links for original content and any more details, such as alternate solutions, latest updates/developments on topic, comments, revision history etc. For example, the original title of the Question was: Postgres find types used in procedures and user-defined functions

Also, Content (except music) licensed under CC BY-SA https://meta.stackexchange.com/help/l...
The original Question post is licensed under the 'CC BY-SA 4.0' ( https://creativecommons.org/licenses/... ) license, and the original Answer post is licensed under the 'CC BY-SA 4.0' ( https://creativecommons.org/licenses/... ) license.

If anything seems off to you, please feel free to write me at vlogize [AT] gmail [DOT] com.
---
Exploring User-Defined Types in PostgreSQL Procedures

When working with PostgreSQL, developers often create user-defined types and domains that enhance the functionality of their databases. As the complexity of your database increases, tracking these custom types and understanding their usage becomes crucial, especially within stored procedures and user-defined functions. However, finding a comprehensive list of types used in these stored objects is not as straightforward as one might hope.

The Challenge of Finding User-Defined Types

Understanding the Problem

The main challenge in retrieving user-defined types used in PostgreSQL functions lies in how the database stores the code for these functions. Unlike standard SQL commands, the body of functions is kept as a string. This obscures the direct access to the types and domains defined within them, making it difficult to compile a complete list.

Why Manual Search is Not Effective

A common workaround might be to perform a substring search in the source code of the functions, but this method is notoriously unreliable. Here’s why:

Varying Procedural Languages: PostgreSQL supports numerous procedural languages (like PL/pgSQL, PL/Perl, PL/Python, etc.), each with unique syntax and conventions. This diversity complicates parsing the function body consistently.

String Complexity: Functions can encompass long and complex strings, making it challenging to accurately capture all instances where a custom type is used.

Human Error: When dealing with manual parsing, the likelihood of oversight increases, potentially leaving out important information.

Suggested Approaches for Finding User-Defined Types

While there is no direct command to extract this information easily, there are some methods you can consider to attempt to piece together the information you need.

1. Utilizing pg_dump

One practical method is to use the pg_dump tool to export the database schema. By focusing on the functions, you can get an overview of their definitions which will include user-defined types. Here’s how you can approach this:

Run the command:

[[See Video to Reveal this Text or Code Snippet]]

Open the schema.sql file and search for the type definitions manually.

2. Using Regular Expressions

If you are familiar with programming, using regular expressions can aid in searching through the function bodies for specific user-defined types. You can write a script in languages such as Python or Perl to process the function definitions and extract relevant types.

3. PG Admin or Other GUI Tools

Using tools like PG Admin allows you to visually explore your database objects. You can view the function definitions and types interactively, albeit requiring effort to manually check each function.

Conclusion

In summary, while there is no straightforward command in PostgreSQL to list user-defined types and domains used in procedures and functions, combining tools like pg_dump with smart searching techniques can help you gather the required information. However, be prepared for a bit of manual effort and the possibility of encountering inconsistencies. By familiarizing yourself further with the unique characteristics of your procedural code and making use of available tools, you can effectively navigate this challenge and maintain a well-organized database structure.