Crosswalks

Crosswalks are analogous to the Primary Key or Unique Identifier in RDBMS.

Data may come to Reltio from multiple sources. Each source must be registered in Reltio, and all data loaded into a tenant will be associated with a data source. If no source is specified when creating an object, the source will default to "Reltio". Crosswalks do not just apply to the entity level, Reltio associates each supplied attribute with data provider crosswalks.

A crosswalk can represent a data provider or a non-data provider:

  • Data providers supply attribute values for an object and the attributes are associated with the crosswalk.
  • Non-data providers are associated with an overall entity (or relationship). In this case it is simply used to link a Reltio object with an object in another system. Supplied attributes will NOT be associated with this crosswalk.

It is important to preserve the uniqueness of a crosswalk. For example, if two objects in Reltio platform contain the same crosswalk, it indicates that they are both the same object in another system and therefore are logically the same entity, thus they must be merged. In fact, one way to automatically merge records in Reltio platform is to intentionally give objects identical crosswalks. This strategy is often used during a load to circumvent the alternative approach of using match/merge rules after the load has been completed. Since uniqueness is important, Reltio platform forms a complete description of a crosswalk from several elements: source type, crosswalk value, source table (optional), and URL (optional). A crosswalk can contain the following elements:

Table 1. Crosswalk Elements
Element Description
type Unique identifier of a source system. The identifier is created when registering a source in Reltio platform. Two source systems cannot share the same source type.
dataProvider Determines whether attributes are being sourced from this crosswalk or whether we are just linking a Reltio object to a source object. Default is true, we are getting data from this system.
value Assumed to represent a unique entity, often the source system's "primary key" is used as the crosswalk value. This property is required ONLY for entities. Example: Facebook is defined as a source ('configuration/sources/Facebook'). An entity comes from Facebook and its identifier in Facebook is 'joe.smith.1048'. For this entity, we will have a crosswalk with type = 'configuration/sources/Facebook', value = 'joe.smith.1048' and url = 'https://www.facebook.com/joe.smith.1048'.
sourceTable Because many systems only maintain unique primary keys within a single table, sourceTable can be used to ensure uniqueness. For example, a data source called "MediList" provides data on health care professionals "Doctor House" and "Nurse Evans". "MediList" stores nurses and doctors in separate tables, for example, t_nurses and t_doctors. Each table maintains a unique number sequence as the primary identifier, so uniqueness is not guaranteed across those two tables. In this case, both of these records happen to have been assigned identical ID numbers, row_id=456. In Reltio platform, the target entity for both records might be the HCP entity (Health Care Provider). Without a way to ensure uniqueness (since both IDs are 456) these records would be auto-merged during the load because their crosswalks would be equal. You can use the sourceTable element to handle such cases.
URL URL of the value in the source system.

Every entity and relationship must have a crosswalk. A crosswalk consists of:

  • Name of the source (required)
  • ID of an object in the source (required)
  • Source table (optional)
  • URL (optional)

The Sources view on the profile screen displays the source for every attribute of an entity, along with the crosswalk ID.