Controlling Output Timing

Use ouput clauses to delay or regulate the processing of output from a query.

Normally, you can expect output from a query to be delivered immediately upon execution. When a row comes into an input stream, all queries that act upon that stream will execute and, if appropriate, produce output based on that incoming row. Output rows that are produced as a result of query execution will have the timestamp of the incoming row and those output rows, if directed to other queries, will be acted upon immediately. Thus, all actions that act on the incoming row or any of its derived results will appear to occur simultaneously.

However, it may be appropriate to delay or regulate the processing of output from a query, so that "downstream" actions on the results of a query do not occur at the same time. Sybase CEP has a number of ways to control and regulate the processing of query output:

OUTPUT AFTER.
OUTPUT EVERY.
OUTPUT ALL EVERY.
OUTPUT FIRST WITHIN.

Using OUTPUT AFTER
The OUTPUT AFTER clause can be used to delay the output either by a specific time interval or by a specific number of rows.
Using OUTPUT EVERY
The OUTPUT EVERY clause permits the regulation of row publication at specific intervals, based either on time or row counts. This reduces the number of rows that are published.
Using OUTPUT FIRST
Use the OUTPUT FIRST WITHIN clause to return values at the start of timed or row count intervals.

Parent topic: Using CCL