Fabric 1.2 Chaincode namespace _foo_f1_ _foo_f2_ _foo_f3_ _bar_b1_ Collection: Marbles Namespaces for public data objectType “foo”. “foo” has three keys f1, f2 and f3. To make keys unique in Chaincode, composite keys are used. The name of an objectType and a key are concatenated. _<objectType name>_<Key name>_ Underscore shows the prefix or separator of composite keys. Namespaces for public data objectType “bar”. m1 m2 m3 Namespaces for private data objectType “Marbles”. “Marbles” has three keys m1, m2 and m3. The name of collection makes this data objectType unique in Chaincode. We don’t need to use composite keys.

proposal Chaincode namespace Collection?: foo Collection?: bar Collection: Marbles f1 f2 f3 b1 b2 b3 m1 m2 m3 Namespaces for public data objectType “foo”. “foo” has three keys f1, f2 and f3. If we have a function like collection for public data, each key become unique without using composite keys. Namespaces for public data objectType “bar”. Namespaces for private data objectType “Marbles”. “Marbles” has three keys m1, m2 and m3. The name of collection makes this data objectType unique in Chaincode. We don’t need to use composite keys.