I currently manage Netinsight (old IBM web analytic s tool) where we have around 300+ sites and the DB is around 12 TB. And each site has its own set of tables and it creates the indexes which is better is performance.
Where as PIWIK is writing everything to a single table for all the sites, i am not convinced to have 5+ TB of data to a single table and expect the data to be faster.
I would like to know the largest DB which PIWIK can handle. Are there any plans for PIWIK to change this architecture.