Join

Purpose: Join two data sources together based on a condition. Combines rows where the join condition is met, bringing together columns from both sources.

How to use:

• Connect two data sources (left and right inputs)
• Choose a join condition:
  • Equality condition: Match rows where specific columns are equal (e.g., left.id = right.id)
  • Freeform condition: Write a custom SQL expression for more complex joins
• Specify query aliases to distinguish columns from each source

Data transformation:

• Rows from both inputs are joined based on the specified condition
• Creates one output row for each pair of matching rows
• Columns from both inputs are combined into each output row
• If the same column name exists in both sources, columns are prefixed with the query alias
• Only matching rows are included in the output (INNER JOIN behavior)

Example 1 - Equality join: Join slices with processes by matching upid column: slices.upid = processes.upid.

Example 2 - Freeform join: Join based on custom condition: left.start_time < right.end_time AND left.end_time > right.start_time to find overlapping intervals.

Join types: This node performs an INNER JOIN - only rows that match the condition are included in the output.

SQL equivalent: SELECT * FROM left JOIN right ON <condition>