What is the best way to migrate and optimize 300 GB database to drupal? I have a database that was running on a propitiatory system with a hosting company. The data is about 10 years old and mostly text. The database it too large aprox 300GB. We are trying to migrate the database to Drupal and I am wondering if this is a good idea and whether drupal/mysql could support such large databases or not. I have a few thoughts such as archiving the data and using caching tools such as varnish. Is this a good idea? Can drupal support/serve it? What impact could this have on performance?

Edit: We have already migrated the database but performance is a extremely bad. ~17 million nodes, and ~90 million comments. What could I optimize? what kind of infrastructure would you recommend? caching and architecture? Load balancing? Any hints or tips that could help run such big site with drupal is what I need. Case studies if anyone is aware of.
The answer is Yes.
First - because you are asking on Drupal Answers site.
I would recommend you using configuration like this:


0 Load balancer managing several servers
1 Varnish (proxy cache)
2 Nginx (php-fpm)
3 Drupal
4 MySQL (Master+Slave)


Also memcache can be used. The main problem will be when you will try to update/insert new record in DB. All read queries will be managed by caching-proxying systems.
If you need text search - use ApacheSolr.
Try to not views or panels, with such DB size you can have perfomance issues.