Tutorial 11 - Debug PL/pgSQL functions

This tutorial show, how to debug PL/pgSQL database function using KPoGre.

Requirements

KPoGre PL/pgSQL function debugger fronted depends from functionality on the database server side.

• You need PostgreSQL version 8.3 or newer
• PostgreSQL server must be installed with debugger options. See note !
• In posgtresql.conf, you must have something like: shared_preload_libraries = '$libdir/plugins/plugin_debugger.dll'

Note: On Windows You have two possibilites: One click installer - but I can't get debugger to work with this (version 8.3.5). Rather, use pgInstaller msi package, where is option to install debugging functionality.

Open function Debugger

Select function you wish to debug in tree, make right mouse click to display menu and choose Debug function.

KPoGre shows Debugger. Also toolbar is displayed.

Function parameters

If function have any arguments, fill values to table. Convertion rules are the same as in Datatable.

Start debugging

Choose Debugger -> Start in debugger menu item. If debugging starts successfully, KPoGre place execution mark to first line of code. Also, menu and toolbar actions for debugging are enabled. Look at Debugger tab, where are some informations from debugger process.

It is possible to cancel debugging using Debugger -> Stop menu item or pressing toolbar button.

Ataching another functions

When debugger is started, its possible to attach another functions to it. It is necessary for Stepping into called function.

Breakpoints

When debugger is started, its possible to set or drop breakpoints. Place cursor to line, where you want to toggle breakpoint, and use Debugger -> Toggle Breakpoint

If breakpoint is sucessfully set/dropped, mark is placed/removed to left ribbon.

Debugging

You may use obvious actions for function tracing:

• Step over - execute one line and stop.
• Step into - when another function is called, debugger step into it and pause at first line. It works only if you have called function attached to debugger session.
• Continue processing to next breakpoint or end.

Watching and changing Variables

While tracing, you may see variable values. Variables, that are changed from previous pause are highlighted by mark.

It is possible to change varible value, while debugging. Select row with variable and make mouse right click over variables table to show context menu.

Watching output

While tracing, you may see notices, sent from debugged function.

Stack

On Stack tab, you may see informations about function calling hierarchy.

Looking at result

When function is finished, result (if any), it is displayed in result area.

When table result is larger than 500 rows, only 500 rows fetched initially to table. User may fetch another bunch of rows using Debugger -> Fetch next and Debugger -> Fetch all.

If you make mouse right-click over result table, menu containing some clipboard and search actions is displayed.

Content of result table may be saved to CSV file using File -> Export result.