Igloo MCP

# Tool: query_lineage ## Purpose Analyzes data lineage for Snowflake objects, showing dependencies and relationships between tables, views, and other database objects. ## Parameters | Parameter | Type | Required | Description | |-----------|------|----------|-------------| | `object_name` | string | Yes | Name of the object to analyze lineage for | | `direction` | string | No | Direction of lineage analysis: "upstream", "downstream", or "both" (default: "both") | | `depth` | integer | No | Maximum depth of lineage analysis (default: 3) | | `format` | string | No | Output format: "json", "dot", or "text" (default: "json") | | `catalog_dir` | string | No | Directory containing catalog data (default: "./data_catalogue") | | `cache_dir` | string | No | Directory for caching lineage data (default: "./cache") | ## Returns Returns a dictionary containing: - `lineage`: Lineage data in the requested format - `summary`: Text summary of lineage relationships - `object_name`: The analyzed object name - `direction`: The analysis direction - `depth`: The analysis depth ## Examples ### Basic Lineage Analysis ```json { "tool": "query_lineage", "arguments": { "object_name": "MY_DATABASE.MY_SCHEMA.MY_TABLE" } } ``` **Expected Output**: ```json { "lineage": { "upstream": [ { "object": "SOURCE_TABLE", "type": "table", "relationship": "direct" } ], "downstream": [ { "object": "TARGET_VIEW", "type": "view", "relationship": "direct" } ] }, "summary": "MY_TABLE has 1 upstream dependency and 1 downstream dependency", "object_name": "MY_DATABASE.MY_SCHEMA.MY_TABLE", "direction": "both", "depth": 3 } ``` ### Upstream-Only Analysis ```json { "tool": "query_lineage", "arguments": { "object_name": "MY_TABLE", "direction": "upstream", "depth": 2 } } ``` ### DOT Format Output ```json { "tool": "query_lineage", "arguments": { "object_name": "MY_TABLE", "format": "dot" } } ``` **Expected Output**: ```json { "lineage": "digraph lineage {\n \"SOURCE_TABLE\" -> \"MY_TABLE\";\n \"MY_TABLE\" -> \"TARGET_VIEW\";\n}", "summary": "DOT format lineage graph", "object_name": "MY_TABLE", "direction": "both", "depth": 3 } ``` ## Common Use Cases ### Impact Analysis Use `direction: "downstream"` to see what objects depend on a table before making changes. ### Data Source Tracking Use `direction: "upstream"` to trace data back to its original sources. ### Documentation Generation Use `format: "dot"` to generate visual diagrams of data flow. ### Change Management Analyze lineage before schema changes to understand potential impacts. ## Troubleshooting ### Object Not Found **Error**: `Object 'MY_TABLE' not found` **Solution**: - Verify object name spelling - Check object exists in catalog - Ensure proper database.schema.object format ### No Lineage Data **Error**: `No lineage data found` **Solution**: - Build catalog first using `build_catalog` tool - Check if object has dependencies - Verify lineage depth settings ### Performance Issues **Error**: `Query timeout` **Solution**: - Reduce lineage depth - Use specific direction instead of "both" - Check Snowflake warehouse size ## Related Tools - [build_catalog](build_catalog.md) - Build catalog before lineage analysis - [get_catalog_summary](get_catalog_summary.md) - Check catalog status - [build_dependency_graph](build_dependency_graph.md) - Visual dependency mapping - [preview_table](preview_table.md) - Preview table structure ## Notes - Lineage analysis requires a built catalog - Performance depends on lineage depth and object complexity - DOT format output can be rendered with Graphviz - Lineage data is cached for performance