"External unique identifer", "pk" and "internal id" are often mentioned in JavaAPI in Galaxybase. What is the difference between them?
>Solution :
An "external unique identifer", also known as a "pk" (primary key), is a unique identifier for vertex data, used to distinguish different vertex. It is similar to a person’s ID number. A person may have the same name, but not the same ID number. So the ID number is used to distinguish different people.
When Galaxybase loads data, it requires the user to specify an attribute of the the vertex as the "external unique identifer", and Galaxybase will process it in "String" type. When loading or inserting vertex data, Galaxybase assigns a globally unique "internal id" to each vertex data, which is of the type "long".
So there are two ways to identify a point in Galaxybase, either by the "internal id" (long type) or by the "external unique identifer" (i.e. pk, string type).