To perform stream data processing only on specific records, you use a filter as the data editing callback.
For example, if you are monitoring temperatures from a number of observation sites and you want to summarize and analyze temperatures from only one particular observation site, you can filter on that observation site's ID.
Only common records can be filtered. If the input source is a file, after an input record is extracted by the file input connector, you must use the format conversion callback to convert it to a common record before filtering it.
When specifying the evaluation conditions you want to filter on, you can use any of the record formats and values that are defined in the records. The following figure shows the positioning and processing of the callback involved in record filtering.
Figure 3-7 Positioning and processing of the callback involved in record filtering