This PECL extension
is not bundled with PHP.
  Additional information such as new releases,
downloads, source files, maintainer information, and a CHANGELOG, can be
located here: 
  http://pecl.php.net/package/ingres.
 
  In order to have these functions available, you must compile PHP with
  Ingres support by using the
  --with-ingres[=DIR] option, where DIR is
  the Ingres base directory, which defaults to /II/ingres.
  If the II_SYSTEM environment variable isn't correctly set you may have to
  use --with-ingres=DIR
  to specify your Ingres installation directory.
 
  When using this extension with Apache, if Apache does not start
  and complains with "PHP Fatal error: Unable to start ingres_ii
  module in Unknown on line 0" then make sure the environment
  variable II_SYSTEM is correctly set. Adding "export
  II_SYSTEM="/home/ingres/II" in the script that starts Apache, just
  before launching httpd, should be fine.
 
The behaviour of these functions is affected by settings in php.ini.
 
Table 1. Ingres configuration options
| Name | Default | Changeable | Changelog | 
|---|
| ingres.allow_persistent | "1" | PHP_INI_SYSTEM | Available since PHP 4.0.2. | 
| ingres.max_persistent | "-1" | PHP_INI_SYSTEM | Available since PHP 4.0.2. | 
| ingres.max_links | "-1" | PHP_INI_SYSTEM | Available since PHP 4.0.2. | 
| ingres.default_database | NULL | PHP_INI_ALL | Available since PHP 4.0.2. | 
| ingres.default_user | NULL | PHP_INI_ALL | Available since PHP 4.0.2. | 
| ingres.default_password | NULL | PHP_INI_ALL | Available since PHP 4.0.2. | 
| ingres.report_db_warnings | "1" | PHP_INI_ALL | Available since version 1.1.0 of the PECL extension. | 
| ingres.cursor_mode | "0" | PHP_INI_ALL | Available since version 1.1.0 of the PECL extension. | 
| ingres.blob_segment_length | "4096" | PHP_INI_ALL | Available since version 1.2.0 of the PECL extension. | 
 For further details and definitions of the 
PHP_INI_* constants, see the 
Appendix G.