Jira issue originally created by user @beberlei:
Hydration currently fetches the rows and hydrates them by interleaving both operations. This can cause an increased TCP wait time, because the PHP processing takes a bit of time.
We should investigate weather changing to fetchAll() improves the overall performance.
Comment created by @beberlei:
We can introduce a new query hint to allow us to support both: 'DBALFETCHALL'. If that is set, use fetchAll(), otherwise fetchRow().