Jira issue originally created by user mbeccati:
The new pgsql specific PDO attribute has been added in PHP 5.6+ to speed up queries that are going not going to be executed many times once prepared, by skipping the actual PQprepare round trip to the database.
The same goal can be achieved with PDO::ATTREMULATEPREPARES, but that embeds the parameters in the queries which is not recommended.
I'll try to see if I have time to dig into doctrine2 and create a pull request, but I wanted to create a ticket before I forget ;)
Issue was closed with resolution "Fixed"