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Generating and Maintaining Snapshot Files
The program snapshot is a temporary binary file containing the customer-level data elements for a marketing program stage. Data in a snapshot file is extracted based on the elements needed for the segment criteria, output list fields, source code format and campaign load mapping that is associated with the stage. This information is extracted once, allowing the Marketing Server to populate segments with counts and launch a campaign, without having to return to the original data sources to obtain additional information. After generating a snapshot file, you can modify segment criteria (if you do not introduce new elements) and regenerate the gross and net counts without having to requery the data sources and rebuild the result set. For more details about these internal processes, see Understanding Snapshot Generation Internal Processes.
A snapshot is similar to a logical spreadsheet in which the rows (for example, contacts) are determined by the filter that is applied and columns are determined by a union of segment criteria, output file layouts, source code formats and campaign load mapping fields. Filters are applied to the data before the snapshot file is built. Therefore, changing the filter criteria requires that you generate a new snapshot because new rows may need to be added.
The Marketing Server uses a snapshot to determine which customers qualify for each segment and deduplicate any overlapping customers between segments. For example, if your criteria include measures based on income, you might create low, medium and high buckets for ranges of income. The snapshot will contain a list of contacts that satisfy each segment's criteria, indicating the bucket for which each contact qualifies.
When you allocate segments to a campaign offer, Siebel Marketing counts the contacts that meet the criteria and displays the totals to help you allocate segment counts to offers. In the example, if you anticipated mailing an offer to 50,000 contacts in the high income segment and the snapshot shows that only 20,000 contacts qualify in the high bucket, you might want to adjust the salary ranges in the segment criteria and then update the counts.
The following list contains general guidelines for generating and using snapshot files:
- If the data in the data sources change, the updated data is not reflected in the snapshot unless you regenerate the snapshot.
- Changing segment or output file layouts definitions does not require snapshot regeneration if the information was captured in the original snapshot.
- A snapshot file is associated with a program stage and cannot be shared across different stages without additional onsite configuration.
- Use filters to help keep snapshot files as small as possible.
- Applying a constraint to a table can also limit data. A constraint (SQL expression) creates a restricted view of the table. If you add a constraint to the table record, it is applied every time the table is accessed. For more information, see the constraint description in To map a table.
To generate and maintain snapshot files, perform the following tasks:
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Siebel Marketing Guide Published: 23 June 2003 |