Hello,
the content stores in Alfresco are generally configurable, but there is no out-of-the-box configuration item that lets you separate contents by their type. But with a bit of custom Java code (a content store "router") would something like this be possible.
In Alfresco Enterprise Edition there is a "content store selector" aspect that can be used to route contents to different stores based on the value of a metadata property. That could also be used for your requirement and would not require Java code, and could instead make use of JavaScript-based rules / behaviours to set the metadata property to the appropriate value based on the content type on a record.
In content modelling as well as in runtime you can define how certain content classes / records are indexed. In modelling, you can use the cm:indexControl aspect as a mandatory aspect to associate all records of a type or aspect to be restricted in terms of FTS. Basically you can set if recrods should be indexed at all or if only metadata should be indexed.
The aspect cm:indexControl can also be applied at runtime to any record and define how that record is to be treated.
Please note that cm:indexControl currently does not affect transactional queries that are executed against the DB, and depending on your query, Alfresco may transparently switch to use transactional queries instead of index queries (when the query is simple enough).
Regards
Axel