Metadata Column __hevo_id

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 has been ingested.
CleverTap The hash of each Event-payload SHA256-Hash values of each payload that has been ingested.
Facebook Ads The hash of each Event-payload SHA256-Hash values of each payload that has been ingested.
FlatFiles (Google Sheets, CSV files from S3 or FTP/SFTP) rowNumber The row number of each record in the file. (Example, 231)
Google Ad Words The hash of each Event-payload SHA256-Hash values of each payload that has been ingested.
Google Analytics The hash of each Event-payload SHA256-Hash values of each payload that Hash been ingested.
Kafka timestamp-hevo_consumer_id-local_incrementing_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 has been ingested.
MongoDB The hash of the data type of the _id field and its value. Suppose the _id value is numeric 1. Then, __hevo_id is the SHA256 hash of “Integer-1”.
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)
Taboola The hash of all the primary keys SHA256-Hash values of all the primary keys.
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)



Revision History

Refer to the following table for the list of key updates made to this page:

Date Release Description of Change
Jun-28-2021 NA Corrected the hevo_id generation information for FlatFiles (Google Sheets, CSV files from S3 or FTP/SFTP).
Jun-28-2021 1.61 Added a row for __hevo_id determination for MongoDB.
Last updated on 13 Jul 2021