The first thing that you need to ask yourself is,
why do you want to switch to a NoSQL Database?
Answers could be: You need more speed, you want
a replicated and distributed database system,
you need more scalability for used storage
or replication. Or you want to benefit probably
from easier development.
But from 300 records i dont think any, but of the
last would help you.
And i don't think that you really want an "in-memory"
solution. In memory means every data only got written
to ram, and if you close your database, then all your
data is lost. If you really want that then MySQL
have an in-memory Storage engine.
Otherwise all database will cache as lot in-memory
as it can. And 300 records will likely be completly
in your ram also under MySQL. You probably don't get
any speed benefits from switching to a NoSQL database.
If you in general plan to switch to a NoSQL database,
i would prefer MongoDB. It is a mix from NoSQL and
and a RDBMS, because it give you a query language
powerful nearly as SQL. And you can scall it better
than RDBMS. And for me, programming will be a lot
easier against a schema-free database. You can
scale MongoDB up to 1000 servers.
But other NoSQL databases have a lot more scalability.
If you need more Servers, then other databases would
probablby better. But you lose some way to query your
data.
If you generally plan to switch to a NoSQL database
i think MongoDB could handle this. Other NoSQL databases
are probably better for some specific cases and not
for general usage.