Segment Refresh Operations: Understanding Hierarchies and Resource Usage

Parent-Child Segment Relationships

When a Master or Parent Segment is refreshed in Treasure Data, all associated child segments are automatically refreshed as well. This occurs because the refresh operation updates the underlying data tables that both parent and child segments depend on.

Key Points:

• Parent segment refreshes cascade to all child segments
• The refresh updates shared underlying data tables
• This behavior is by design and cannot be disabled

Segment Query Execution Behavior

Segment data in Audience Studio is not cached. Every time you open a segment, the system executes a new query against the database, regardless of how recently you may have viewed the same segment.

Important Details:

• Each segment view triggers a fresh query execution
• The profile count spinner indicates an active segmentation query
• No cached data is used when viewing segments, even for recently accessed segments
• This applies to both parent and child segments equally

Presto Hours Consumption and Billing

All segmentation queries in Treasure Data contribute to Presto split hour usage, which impacts billing. This includes parent segment refreshes, child segment refreshes, and manual segment viewing operations.

Resource Tracking:

• Child segment refreshes do count toward Presto Hours
• The platform does not provide direct visibility into Presto Hours consumption per segment
• Treasure Data Support can provide best-effort estimates of resource usage through backend queries
• These estimates require Support intervention and are not self-service

Best Practices for Managing Segment Refreshes

To optimize Presto hour usage and improve system performance when working with segments:

1. Schedule strategically - Plan parent segment refreshes during off-peak hours to minimize business impact

2. Minimize segment views - Limit opening segments unnecessarily since each view operation triggers a resource-intensive query

3. Optimize query complexity - Design segment queries with performance in mind; simpler queries generally consume fewer resources

4. Consolidate where possible - Reduce the total number of segments by combining similar segmentation logic to decrease the total refresh operations required

5. Request usage analysis - Contact Treasure Data Support for detailed Presto hour consumption reporting to identify optimization opportunities