a1d1833a40
add analyze plan api to allow executing the queries and see runtime metrics. Which help identify the query IO overhead and help identify query slowness
2.1 KiB
Getting help
The following sections provide various diagnostics and troubleshooting tips for LanceDB. These can help you provide additional information when asking questions or making error reports.
For trouble shooting, the best place to ask is in our Discord, under the relevant language channel. By asking in the language-specific channel, it makes it more likely that someone who knows the answer will see your question.
Common issues
- Multiprocessing with
forkis not supported. You should usespawninstead. - Data returned by queries may not reflect the most recent writes, depending on configuration. LanceDB uses eventual consistency by default. See consistency for more information.
Enabling logging
To provide more information, especially for LanceDB Cloud related issues, enable
debug logging. You can set the LANCEDB_LOG environment variable:
export LANCEDB_LOG=debug
You can turn off colors and formatting in the logs by setting
export LANCEDB_LOG_STYLE=never
Explaining query plans
If you have slow queries or unexpected query results, it can be helpful to
print the resolved query plan. You can use the explain_plan method to do this:
- Python Sync: [LanceQueryBuilder.explain_plan][lancedb.query.LanceQueryBuilder.explain_plan]
- Python Async: [AsyncQueryBase.explain_plan][lancedb.query.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][lancedb.query.LanceQueryBuilder.analyze_plan]
- Python Async: [AsyncQueryBase.analyze_plan][lancedb.query.AsyncQueryBase.analyze_plan]
- Node @lancedb/lancedb: LanceQueryBuilder.analyzePlan