Every row in Sybase CEP has an associated row timestamp. When a stream or window is viewed in a Sybase CEP Studio viewer, this timestamp value appears as the left-most column of each data row.
Even though the row timestamp looks like a column in the Studio viewer, it is not an actual column in the row and does not appear in the schema. The row timestamp may not be explicitly modified by a CCL query. However, queries may be written in such a way as to take action based on row timestamp values. In addition, the row timestamp values of output rows may be implicitly controlled by the results of certain kinds of CCL queries (specifically joins and output-regulated queries).
In addition to the row timestamp, which is required by Sybase CEP Engine, other timestamps may also be included in a row as actual data columns. These timestamps may be used in any expression in a CCL query, and may even be explicitly modified as the row moves through a sequence of queries. These timestamps are not used in any way by Sybase CEP to control the sequencing of events.