All streams, windows, and delta streams use three implicit columns called ROWID, ROWTIME, and BIGROWTIME.
| Column | Datatype | Description |
|---|---|---|
| ROWID | long | Provides a unique row identification number for each row of incoming data. |
| ROWTIME | date | Provides the last modification time as a date with second precision. |
| BIGROWTIME | bigdatetime | Provides the last modification time of the row with microsecond precision. You can perform filters and selections based on these columns, like filtering out all of those data rows that occur outside of business hours. |
You can refer to these implicit columns just like any explicit column (for example, using the stream.column convention).