Thanks for your reply it has improved the time of loading. Reviewing your tests I have seen that you are using memcahed. This is a feature which I don´t have installed yet. I was reading about it and I suppose that it can improve the performance by caching the content from the database ( I figure up that APC only catches the php code). Is that true?
I would like to comment that I added a new post in this forum about the oci8 driver and its configuration in:
https://moodle.org/mod/forum/discuss.php?d=215970
If you don´t mind I would be interested in your opinion about this issue. Thanks for all