# Profiling Your Application

The Profiler Class will display benchmark results, queries you have run, and `$_POST` data at the bottom of your pages. This information can be useful during development in order to help with debugging and optimization.

## Initializing the Class

Important

This class does NOT need to be initialized. It is loaded automatically by the Output Library if profiling is enabled as shown below.

## Enabling the Profiler

To enable the profiler place the following line anywhere within your Controller methods:

    $this->output->enable_profiler(TRUE);

When enabled a report will be generated and inserted at the bottom of your pages.

To disable the profiler you will use:

    $this->output->enable_profiler(FALSE);

## Setting Benchmark Points

In order for the Profiler to compile and display your benchmark data you must name your mark points using specific syntax.

Please read the information on setting Benchmark points in the Benchmark Library page.

## Enabling and Disabling Profiler Sections

Each section of Profiler data can be enabled or disabled by setting a corresponding config variable to TRUE or FALSE. This can be done one of two ways. First, you can set application wide defaults with the application/config/profiler.php config file.

Example:

    $config['config']          = FALSE;
    $config['queries']         = FALSE;

In your controllers, you can override the defaults and config file values by calling the `set_profiler_sections()` method of the Output Library:

    $sections = array(
            'config'  => TRUE,
            'queries' => TRUE
    );

    $this->output->set_profiler_sections($sections);

Available sections and the array key used to access them are described in the table below.

Key | Description | Default
--- | --- | ---
benchmarks | Elapsed time of Benchmark points and total execution time | TRUE
config | CodeIgniter Config variables | TRUE
controller_info | The Controller class and method requested | TRUE
get | Any GET data passed in the request | TRUE
http_headers | The HTTP headers for the current request | TRUE
memory_usage | Amount of memory consumed by the current request, in bytes | TRUE
post | Any POST data passed in the request | TRUE
queries | Listing of all database queries executed, including execution time | TRUE
uri_string | The URI of the current request | TRUE
session_data | Data stored in the current session | TRUE
query_toggle_count | The number of queries after which the query block will default to hidden. | 25

Note

Disabling the save_queries setting in your database configuration will also effectively disable profiling for database queries and render the ‘queries’ setting above useless. You can optionally override this setting with `$this->db->save_queries = TRUE;`. Without this setting you won’t be able to view the queries or the last_query <database/helpers>.