What will be the maximum number of connections to Oracle from the PHP-FPM server?

Question

PHP

There is a server with PHP5-FPM + NGINX, one master process and 4 workers. The oci8 module for Oracle DB is attached to it.
Orakl is able to keep persistent connections, and PHP in turn to limit their number by means of oci8.max_persistent in php.ini.

If max connections in php.ini = 25, then it will be correct to assume that the total number of connections = 4 processes x 25 = 100?
And how will the child threads of FPM workers behave in this case? Will they take on another 25 connections each.

The question was asked because after setting max_persistent = 5, 42 connections flies lightly to the server. In a word, incomprehensibility.