I will briefly explain the differences between the two kinds of delta transmission supported by EC Compound Employee API.
Compound Employee API Overview
Compound Employee API, a SOAP-based web service inside EC, is commonly used to synchronize employee master data between Employee Central and other on-demand or on-premise applications. Replication of employee master data by calling Compound Employee API happens synchronously, which means that the response is immediately returned. The Compound Employee API response is structured very similar to the data structures in Employee Central. It returns data about new employees and about changes of employee data.
Compound Employee API delta transmission
Two different kind of delta transmission are supported Compound Employee AP, these are:
Effective dated delta transmission is designed for consumers that work in an effective dated manner, where consumers store the time frame (start and end date) when a data record is effective. Deltas are only communicated for entities, which have been created, changed or deleted since the last replication, independently whether these are retroactive or future-dated changes.
Period-based delta transmission is intended for consumers that are not able to deal with effective dated objects. The following type of changes on effective dated entities are considered when using period-based delta transmission:
- Changes that happened after the last synchronization on effective dated entities with validity in the past or with a validity overlapping with the given period
- Changes on effective dated entities where the start date falls into the given period but changes were done in the past
The query response of the API contains in both cases action codes as a clear indication for each element on how to process the data on consumer side. Additionally, changed attributes are obvious since the current and the previous value of the attribute are part of the query response.
Not-effective dated objects, like national IDs or email are returned in both kinds of delta transmission, if these are changed after the last replication.
Effective dated versus period-based delta transmission
In the example below, an employee was hired and created in the system in September. Mid of October the job data of the employee was changed via ‘Make correction’. Today (end of October) the salary was changed becoming effective mid of October and the address was changed becoming effective in November. The last synchronization of the consumer took place before the change of the job data.
In effective dated delta transmission Compound Employee API returns all changes that happened since the last synchronization, i.e. the change of the job, the change of the salary and the future address change.
For a consumer using period-based delta transmission and providing October 1st to October 31st as synchronization period, only the change of the job and the change of the salary will be replicated, since these changes affect the given period and the data, which has already been replicated to the consumer in the past. However, the change of the address remains unconsidered and will first be transmitted in the next period of November, if it becomes effective.