Scaling and performance SQL or NoSQL
I have read a few mini books on the use of NoSQL such as CouchDB or MongoDB (the latter of which I am more familiar). 

What would be more appropriate in terms of performance - especially scaling:

1. Individual DB's hosted on distinct servers if needed
2. A single MongoDB partitioned using sharding

I left out SQL scaling techniques such as master-slave (which is what I understand is the way you scale SQL with applications that out-grow their servers).

Each "account" in my application will be for personal use only and won't likely grow to insane sizes or access. So I figure I could have the application hosted on one or a few servers with the data spread out across one or more servers as required. When one SQL tapped out I would relocate half (proportionally speaking in terms of usage) of the DB's to another server (remote or not). This should in theory provide some performance boost allowing to me scale somewhat with little effort???

Alternatively sharing in NoSQL solutions sounds pretty easy - the only side effect being I need to keep all records in a singe database - decreasing individual security a slight - in theory? 

What are your experiences/opinions on this matter?

Regards,
Alex
Scaling and performance SQL or NoSQL
===

I have read a few mini books on the use of NoSQL such as CouchDB or MongoDB (the latter of which I am more familiar). 

What would be more appropriate in terms of performance - especially scaling:

1. Individual DB's hosted on distinct servers if needed
2. A single MongoDB partitioned using sharding

I left out SQL scaling techniques such as master-slave (which is what I understand is the way you scale SQL with applications that out-grow their servers).

Each "account" in my application will be for personal use only and won't likely grow to insane sizes or access. So I figure I could have the application hosted on one or a few servers with the data spread out across one or more servers as required. When one SQL tapped out I would relocate half (proportionally speaking in terms of usage) of the DB's to another server (remote or not). This should in theory provide some performance boost allowing to me scale somewhat with little effort???

Alternatively sharing in NoSQL solutions sounds pretty easy - the only side effect being I need to keep all records in a singe database - decreasing individual security a slight - in theory? 

What are your experiences/opinions on this matter?

Regards,
Alex