ETL Step 8: TSNP
In the TSNP step, the system maintains snapshot tables. The system copies all records from *_EXT tables to *_TSNP tables to keep a snapshot. The *_TSNP tables are used as a source for prefilled data and also for Change Data Capture.
The system also updates the LAST_EXTRACTION_VALUE field of the DATA_SOURCE_CDC_STAMP table. Extract Engine extracts data from the PPM database incrementally based on the value of this field. The *_TSNP tables track the change history of the PPM data as well.
*_EXT tables are input in this step while *_ TSNP tables are output.
The following table lists the key staging tables.
|
Table Name |
Table Description |
|---|---|
|
<SOURCE_PRODUCT>_<TARGET_ENTITY_NAME>_<MD_SOURCE_INSTANCE_ID>_TSNP |
Snapshot tables that contain data extracted from PPM. It contains both the latest data and the history data. |
|
DATA_SOURCE_CDC_STAMP |
A table in the management schema. Extractor Engine relies on this field to extract data incrementally. |
