pldbgapi

Overview

Version

Install

You can install pldebugger directly. First, make sure the PGDG repository is added and enabled:

pig repo add pgdg -u          # Add PGDG repo and update cache

Install the extension using pig or apt/yum/dnf:

• Install
• pig
• dnf
• apt

pig install pldebugger;          # Install for current active PG version

pig ext install -y pldebugger -v 18  # PG 18
pig ext install -y pldebugger -v 17  # PG 17
pig ext install -y pldebugger -v 16  # PG 16
pig ext install -y pldebugger -v 15  # PG 15
pig ext install -y pldebugger -v 14  # PG 14

dnf install -y pldebugger_18       # PG 18
dnf install -y pldebugger_17       # PG 17
dnf install -y pldebugger_16       # PG 16
dnf install -y pldebugger_15       # PG 15
dnf install -y pldebugger_14       # PG 14

apt install -y postgresql-18-pldebugger   # PG 18
apt install -y postgresql-17-pldebugger   # PG 17
apt install -y postgresql-16-pldebugger   # PG 16
apt install -y postgresql-15-pldebugger   # PG 15
apt install -y postgresql-14-pldebugger   # PG 14

Preload:

shared_preload_libraries = 'pldbgapi';

Create Extension:

CREATE EXTENSION pldbgapi;

Usage

Sources: repo README, v1.10 release, extension control

pldbgapi provides a server-side API for interactive debugging of PL/pgSQL functions. It is typically used through a GUI client such as pgAdmin.

CREATE EXTENSION pldbgapi;

Debugging with pgAdmin

The primary way to use the debugger is through pgAdmin’s graphical interface:

• Direct Debugging: Right-click a function and select “Debug” to execute and step through it immediately
• Global Breakpoints: Select “Set Global Breakpoint” on a function, then wait for another session (e.g., a web application) to call that function – the debugger will intercept the call and allow in-context debugging

Debugging Capabilities

When connected through a debug client, you can:

• Set breakpoints on specific lines in PL/pgSQL functions
• Step through code line by line (step into, step over, step out)
• Inspect variables and their current values at each step
• View the call stack for nested function calls
• Continue execution to the next breakpoint

Architecture

The debugging system has three components:

1. Client GUI (pgAdmin) – displays source code, variables, and stack
2. Target Backend – the session executing the PL/pgSQL code being debugged
3. Debugging Proxy – coordinates between the client and target via a dedicated connection

Supported Languages

The debugger works with PL/pgSQL functions and procedures. It requires the pldbgapi extension to be created in each database where debugging is needed.

Caveats

• The package name is pldebugger, while the extension created in SQL is pldbgapi; the catalog tracks package version 1.10 for PostgreSQL 14 through 18.
• The v1.10 upstream release is a PostgreSQL compatibility update and does not document a new user-facing SQL API or debugging workflow.
• Upstream troubleshooting says shared_preload_libraries = '$libdir/plugin_debugger' must be configured and PostgreSQL restarted. Missing or incorrect preload prevents global breakpoints and can also prevent pldbgapi SQL from loading on some platforms.