An identifier is a column or combination of columns that uniquely defines a specific ESP Schema.
Identifiers in the ESP Schema model become keys on tables in the SAP Sybase IQ, SAP HANA, and ASE physical models.
Each ESP Schema can have at most one primary identifier, which becomes the primary key in the generated table.
When an identifier has multiple attributes, the primary key in the destination table is composed of multiple columns. For example, in the sample model, the Dividend Event schema has one identifier. Attributes for this primary identifier are Instrument and Disbursed Date. Thus the primary key for the Dividend Event table is composed of both the Instrument and Disbursed Date columns.