I realise this question may have be answered in some form but I would like to gather the thoughts and opinions of actual users with experience in this field of Database design and development. I have a 'large' financial time series database, close to 150GB and growing at a rate of about 4GB per day. Currently I am using MySQL as my database engine, however I am concerned about scalability and performance in future. I have read conflicting reports on alternative solutions (MySQL, Postgres, Cassandra, Datomic, KDB+ etc etc), and with the 100s of Database technologies available one is left somewhat unsure. That's why personal experience of users I think would be invaluable.
Before anyone mentions the obvious such as KDB+, the issue I have with that is that it is predominantly an 'in-memory' database - not ideal for me. I understand it would be great for high frequency traders but that is not the nature of my research.I would prefer a scalable, on disk, SQL solution? Happy to hear thoughts and discuss.