how is it possible that runs entirely in-memory instead of on disk

Question

VoltDB runs entirely in-memory instead of on disk. I am wondering how is this possible if say our data is increasing and increasing yet ram is a limited resource, wouldn't it start to hit some bottlenecks real soon?

Answer 1

In-memory databases are usually designed to be used as clusters. To scale as the size of the database grows, you have to increase one of these so the database fully fits in memory:

• The memory of the server.
• The number of servers in the database cluster.

Answer 2

I don't know anything about this DB, but it's possible to do this. You just need a lot of computers(nodes). If you need more "space" add another (pair, triple of) node(s)...

Answer 3

With an in-memory database you'll need enough physical RAM to hold the state of your application. You can certainly move stale/static data along to a long-term data store for reporting and analysis.

Answer 4

Only if your data is growing faster than memory prices are going down. Most databases are much smaller than the maximum ram size of a modern workstation if they are normalized and excluding blobs/images/files.