plDebugger2

This module is a set of shared libraries which implement an API for debugging functions & procedures on PostgreSQL 9.4+. The pgAdmin4 project (http://www.pgadmin.org/) provides a lovely client user interface.

History

This project was originally authored by Korry Douglas in 2004. In 2005, as Founder/CTO of EnterpriseDB, Denis Lussier sponsored young Korry to Open Source this project for the benefit of the Postgres Community.

Building from source

• Copy this directory to contrib/ in your PostgreSQL source tree.

• Run 'make; make install'

• Edit your postgresql.conf file, and modify the shared_preload_libraries config option to look like:

  shared_preload_libraries = '$libdir/plugin_debugger'

• Restart PostgreSQL for the new setting to take effect.

• Run the following command in the database or databases that you wish to debug functions in:

  CREATE EXTENSION pldbgapi;

Usage

Connect pgAdmin4 to the database containing the functions you wish to debug. Right-click the function to debug, and select Debugging->Debug to execute and debug the function immediately, or select Debugging->Set Global Breakpoint to set a breakpoint on the function. This will cause the debugger to wait for another session (such as a backend servicing a web app) to execute the function and allow you to debug in-context.

For further information, please see the pgAdmin documentation.

Architecture

The debugger consists of three parts:

1. The client. This is typically a GUI displays the source code, current stack frame, variables etc, and allows the user to set breakpoints and step throught the code. The client can reside on a different host than the database server.

2. The target backend. This is the backend that runs the code being debugged. The plugin_debugger.so library must be loaded into the target backend.

3. Debugging proxy. This is another backend process that the client is connected to. The API functions, pldbg_* in pldbgapi.so library, are run in this backend.

The client is to connected to the debugging proxy using a regular libpq connection. When a debugging session is active, the proxy is connected to the target via a socket. The protocol between the proxy and the target backend is not visible to others, and is subject to change. The pldbg_* API functions form the public interface to the debugging facility.

debugger client ------ libpq -------- Proxy backend (pgAdmin) * | pldebugger socket connection | * application client ----- libpq ------- Target backend

License

The pldebugger API is released under the Artistic License v2.0.

https://opensource.org/licenses/artistic-license-2.0

Copyright (c) 2019-2020 BigSQL. All rights reserved.

Portions Copyright (c) 2004-2018 EnterpriseDB Corporation. All Rights Reserved.