Metadata Column __hevo_id
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What is __hevo_id?
__hevo_id is added to Events in some Sources which do not provide any Primary Key by default.
In Sources that generate mutable data, a primary key is required to perform updates in the Destination. You can read more about it here.
For Sources that generate immutable data, a Primary key is required to ensure exactly-once delivery semantics. Hevo’s architecture guarantees at-least-once delivery semantics by default. But, by having Primary keys in the Events, Hevo is able to achieve exactly-once delivery semantics. However, if a few duplicates do not affect you a lot, or if you have any other processes to remove duplicates from the Events later, you can choose to not create primary keys in the Destination tables while creating mappings.
How is __hevo_id generated?
| Source | __hevo_id generated from | Examples |
|---|---|---|
| Appsflyer | The hash of each Event-payload | SHA256-Hash values of each payload that have been ingested. |
| CleverTap | The hash of each Event-payload | SHA256-Hash values of each payload that have been ingested. |
| Facebook Ads | The hash of each Event-payload | SHA256-Hash values of each payload that have been ingested. |
| FlatFiles (Google Sheets, CSV files from S3 or FTP/SFTP) | fileName_rowNumber | Sheet’s filename_rowNumber of each record. (filename_1) |
| Google Ad Words | The hash of each Event-payload | SHA256-Hash values of each payload that have been ingested. |
| Google Analytics | The hash of each Event-payload | SHA256-Hash values of each payload that have been ingested. |
| Kafka | timestamp-hevo_consumer_id-local_increamenting_id | Timestamp - Event payload ingested time. Hevo Consumer ID - Hevo Consumer’s Unique ID. Local Incrementing ID - An incrementing id local to each consumer. (1567422223363-278-16) |
| Mixpanel | The hash of each Event-payload | SHA256-Hash values of each payload that have been ingested. |
| REST API | timestamp-hevo_consumer_id-local_increamenting_id | Timestamp - Event payload ingested time. Hevo Consumer ID - Hevo Consumer’s Unique ID. Local Incrementing ID - An incrementing id local to each consumer. (1567422223363-278-16) |
| Webhooks | timestamp-hevo_consumer_id-local_increamenting_id | Timestamp - Event payload ingested time. Hevo Consumer ID - Hevo Consumer’s Unique ID. Local Incrementing ID - An incrementing id local to each consumer. (1567422223363-278-16) |
Last updated on 02 Mar 2021