🔍 Troubleshooting

Getting help

The following sections provide various diagnostics and troubleshooting tips for LanceDB.These can help you provide additional information when asking questions or makingerror reports.

For trouble shooting, the best place to ask is in our Discord, under the relevantlanguage channel. By asking in the language-specific channel, it makes it morelikely that someone who knows the answer will see your question.

Common issues

• Multiprocessing withfork is not supported. You should usespawn instead.

Enabling logging

To provide more information, especially for LanceDB Cloud related issues, enabledebug logging. You can set theLANCEDB_LOG environment variable:

exportLANCEDB_LOG=debug

You can turn off colors and formatting in the logs by setting

exportLANCEDB_LOG_STYLE=never

Explaining query plans

If you have slow queries or unexpected query results, it can be helpful toprint the resolved query plan. You can use theexplain_plan method to do this:

• Python Sync:LanceQueryBuilder.explain_plan
• Python Async:AsyncQueryBase.explain_plan
• Node @lancedb/lancedb:LanceQueryBuilder.explainPlan

To understand how a query was actually executed—including metrics like execution time, number of rows processed, I/O stats, and more—use the analyze_plan method. This executes the query and returns a physical execution plan annotated with runtime metrics, making it especially helpful for performance tuning and debugging.

• Python Sync:LanceQueryBuilder.analyze_plan
• Python Async:AsyncQueryBase.analyze_plan
• Node @lancedb/lancedb:LanceQueryBuilder.analyzePlan