The behaviour of these functions is affected by settings in php.ini.
| Name | Default | Changeable | Changelog | 
|---|---|---|---|
| ibase.allow_persistent | "1" | PHP_INI_SYSTEM | |
| ibase.max_persistent | "-1" | PHP_INI_SYSTEM | |
| ibase.max_links | "-1" | PHP_INI_SYSTEM | |
| ibase.default_db | NULL | PHP_INI_SYSTEM | Available since PHP 5.0.0. | 
| ibase.default_user | NULL | PHP_INI_ALL | |
| ibase.default_password | NULL | PHP_INI_ALL | |
| ibase.default_charset | NULL | PHP_INI_ALL | Available since PHP 5.0.0. | 
| ibase.timestampformat | "%Y-%m-%d %H:%M:%S" | PHP_INI_ALL | |
| ibase.dateformat | "%Y-%m-%d" | PHP_INI_ALL | |
| ibase.timeformat | "%H:%M:%S" | PHP_INI_ALL | 
Here's a short explanation of the configuration directives.
ibase.allow_persistent
    boolean
   Whether to allow persistent connections to Firebird/InterBase.
ibase.max_persistent
    integer
   The maximum number of persistent Firebird/InterBase connections per process. New connections created with ibase_pconnect() will be non-persistent if this number would be exceeded.
ibase.max_links
    integer
   The maximum number of Firebird/InterBase connections per process, including persistent connections.
ibase.default_db
    string
   The default database to connect to when ibase_[p]connect() is called without specifying a database name. If this value is set and SQL safe mode is enabled, no other connections than to this database will be allowed.
ibase.default_user
    string
   The user name to use when connecting to a database if no user name is specified.
ibase.default_password
    string
   The password to use when connecting to a database if no password is specified.
ibase.default_charset
    string
   The character set to use when connecting to a database if no character set is specified.
ibase.timestampformat
    string
   
ibase.dateformat
    string
   
ibase.timeformat
    string
   These directives are used to set the date and time formats that are used when returning dates and times from a result set, or when binding arguments to date and time parameters.