4 ms·

I've seen a lot of these new SQL databases, and they all seem to compare themselves to MySQL. That seems like a particularly easy target, since MySQL's main str

by Shish2k 14y ago

I've seen a lot of these new SQL databases, and they all seem to compare themselves to MySQL. That seems like a particularly easy target, since MySQL's main strength is speed, and it's a fundamentally old-school (ie slow) design which has sacrificed everything else to get half-fast. What I'd like to know is how any of these compare in features and reliability to the featureful, reliable databases like Oracle and Postgres. (For specific examples that I've run into recently: does it have geo-spatial extensions, and does it crash and burn and corrupt all its data if a malloc() fails)

chris_wot 14y ago
It still uses a transaction log, but seems to make snapshots of the logs at a period of time to create compressed snapshots of the data itself. You can turn off durability, but then you risk losing everything. For features... forget about geo-spatial extensions - they can only do read-committed isolation level... but as they only allow for one SQL statement per transaction I suppose this might not be such a big concern. If you were using this for something like a session management database, or something where durability is not so important then it's probably fine. Not sure I'd use it for anything that relies heavily on transaction management features. I see other limitations, like it cannot support CHANGE COLUMN, and it can't do joins on more than 2 tables. Actually, it doesn't look like it can do FULL OUTER or RIGHT OUTER joins, either. :(
- nikita 14y ago
  Memsql is a database that does some things incredibly well: deliver on high throughput for on small transactions and some things not as well (surface area). Of course a new product will have certain limitation which will be removed as the product matures.
  - chris_wot 14y ago
    No probs, like I've said elsewhere, not attacking the product. Looks very interesting! I guess I'm trying to work out what sort of market you are trying to target here.
tintor 14y ago
"and does it crash and burn and corrupt all its data if a malloc() fails" MemSQL is fully durable (with option of sync and async durability, similar to sync and async replication) with its transactional log. If MemSQL process is killed it will recover all commited transactions on the next startup. Durability has very little performance cost on throughput as MemSQL uses only sequential I/O. And of course, durability can be completely turned off for maximum performance.

by Shish2k 14y ago

chris_wot 14y ago

It still uses a transaction log, but seems to make snapshots of the logs at a period of time to create compressed snapshots of the data itself. You can turn off durability, but then you risk losing everything. For features... forget about geo-spatial extensions - they can only do read-committed isolation level... but as they only allow for one SQL statement per transaction I suppose this might not be such a big concern. If you were using this for something like a session management database, or something where durability is not so important then it's probably fine. Not sure I'd use it for anything that relies heavily on transaction management features. I see other limitations, like it cannot support CHANGE COLUMN, and it can't do joins on more than 2 tables. Actually, it doesn't look like it can do FULL OUTER or RIGHT OUTER joins, either. :(

nikita 14y ago
Memsql is a database that does some things incredibly well: deliver on high throughput for on small transactions and some things not as well (surface area). Of course a new product will have certain limitation which will be removed as the product matures.
- chris_wot 14y ago
  No probs, like I've said elsewhere, not attacking the product. Looks very interesting! I guess I'm trying to work out what sort of market you are trying to target here.

tintor 14y ago

"and does it crash and burn and corrupt all its data if a malloc() fails" MemSQL is fully durable (with option of sync and async durability, similar to sync and async replication) with its transactional log. If MemSQL process is killed it will recover all commited transactions on the next startup. Durability has very little performance cost on throughput as MemSQL uses only sequential I/O. And of course, durability can be completely turned off for maximum performance.