DevOps, CI/CD and Automation

Hi,

I have Oracle HTTP server and switched to new PHP 5.1.2 to use persistent connections.
In php.ini:
oci8.privileged_connect = 0
oci8.max_persistent = 2
oci8.persistent_timeout = 1200
oci8.ping_interval = -1
oci8.statement_cache_size = 20

phpinfo() confirms that :)
---
I just run on test database and single browser session - no one else is using this server.
After some time (30 mins) I have more then 2 session eg. 5.

I've figured out, that calls to oci_pconnect with the same user/pass@db that are in about 60 seconds interval do not open new session - it reuses previous one.
If interval between calls is bigger, new session is created.
Is this an bug, or something is configured incorrectly?

Regards,
Pawel