Hi Anish,

There are several things that could explain why a pipeline with fewer tables takes longer to initialize and load. The number of tables alone does not determine pipeline performance — it depends on the complexity of each flow, data volumes, and how the pipeline is configured. Here are some concrete steps to debug this:

1. Check the event log for timing breakdowns

Query the pipeline event log for flow_progress events to see per-table duration_seconds. This will tell you exactly which tables in the slower pipeline are taking the most time during initialization and data loading. Also look at update_progress events to see how long the INITIALIZING and SETTING_UP_TABLES phases take.

2. Look at the INITIALIZING and SETTING_UP_TABLES phases

During INITIALIZING, the pipeline builds its logical plan and dependency graph — complex dependencies or CDC transformations add overhead here. During SETTING_UP_TABLES, schema validation and table state assessment happen for every defined table. If the 20-table pipeline has more complex transformations (e.g., apply_changes / SCD operations, many views, or heavier joins), it could take longer than the 40-table pipeline with simpler flows.

3. Check for driver bottlenecks

Monitor driver CPU and memory. Even with fewer tables, if the individual streaming flows are more resource-intensive (larger state, more complex logic), the driver can become a bottleneck.

4. Compare data volumes and file counts

Use the operation_progress events in the event log to check Auto Loader file listing counts and backlog bytes. The slower pipeline may be processing significantly more data per table, or dealing with many small files which degrade read performance.

5. Review pipeline mode

If both pipelines are in triggered mode, they perform initialization steps on every trigger. Continuous pipelines only initialize on restart. If only the slower one is triggered, that could explain the difference.

Sources:

• Fixing high initialization times in pipelines
• Monitor pipeline event logs
• Pipeline best practices