This table maps Segment-generated identifiers, like`segment_id`, to external identifiers that your users provide.

This table maps Segment-generated identifiers, like`segment_id`, to external identifiers that your users provide. It has the following columns:

| field| description|

| -----------------------------| ---------------------------------------------------------------------------------------------------|

|`EXTERNAL_ID_HASH`| The hash of the identifier sent in the incoming event.|

|`EXTERNAL_ID_TYPE`| The type of external identifier sent in the incoming event, such as`user_id` or`anonymous_id`. External identifiers become the identities attached to a user profile.|

|`EXTERNAL_ID_VALUE`| The value of the identifier sent in the incoming event.|

|`ID`| A unique identifier for the table row.|

|`RECEIVED_AT`| The timestamp when the Segment API receives the payload from the client or server.|

|`SEGMENT_ID`| The Profile ID that Segment appends to an event or an identifier at the time it was first observed.|

|`SEQ`| A sequential value derived from the timestamp.|

|`TIMESTAMP`| The UTC-converted timestamp set by the Segment library.|

|`TRIGGERING_EVENT_ID`| The specific ID of the incoming event.|

|`TRIGGERING_EVENT_NAME`| The specific name of the incoming event.|

|`TRIGGERING_EVENT_SOURCE_ID`| The specific source ID of the incoming event.|

|`TRIGGERING_EVENT_SOURCE_NAME`| The name of the source that triggered the event.|

|`TRIGGERING_EVENT_SOURCE_SLUG`| The slug of the source that triggered the event.|

|`TRIGGERING_EVENT_TYPE`| The type of tracking method used for triggering the incoming event.|

|`UUID_TS`| A unique identifier of the timestamp.|

The anonymous site visits sample used earlier would generate the following events: