This article will help you organize common problems in the application of MaxCompute Lightning.

  • Q: How can I query data using MaxCompute Lightning when I have not created any tables?

    A: You need to use the DataWorks or odpscmd client tool to create tables for a MaxCompute project and then upload the data. You can access the project using MaxCompute Lightning and query the tables in the project.

  • Q: What are the limits on the amount of data that I can query? What is the limit to the amount of queried data MaxCompute Lightning can process and still show excellent performance?
    A: Currently, a maximum of 1 TB data can be scanned for a table in each query. Of course, less of queried data will provide better query performance.
    Note We recommend that the table data to be scanned does not exceed 100 GB. Query performance gradually decreases with the increase of data volume. If the queried data exceeds 100 GB, MaxCompute SQL is recommended for better performance.
  • Q: What should I do if I receive the following error message when using BI tools to drag a partitioned table for analysis: ERROR: AXF Exception: specified partitions count in odps table: <project_name.table_name> is: xxx, exceeds the limitation of xxx, please add stricter partition filter.

    A: MaxCompute Lightning limits the number of partitions for a partitioned table to ensure the query performs efficiently. A maximum of 1,024 partitions can be scanned for a table in each query. With some BI tools, you can select tables for analysis using the drag-and-drop method. In this way, you are not able to specify partition settings before the analysis. This may cause the number of partitions to be scanned to exceed the limit, triggering the report of an error from MaxCompute Lightning. We recommend that you process the to-be-queried tables before the analysis. You can either convert partitioned tables into non-partitioned tables or reduce the number of partitions to a value lower than 1,024.

  • Q: Why is ERROR: SSL required displayed during the connection to MaxCompute Lightning?

    A: MaxCompute Lightning requires SSL connections and therefore users must use SSL connections. If you use a client tool, you can select the SSL connection check box. If SSL connections cannot be selected in the client tool, you can add the SSL parameter to the JDBC URL. In the JDBC URL, you must enter the endpoint of the region where your project belongs and the name of the connected project, for example, jdbc:postgresql://lightning.cn-shanghai.maxcompute.aliyun.com:443/myproject? ssl=true.

  • Q: What should I do when I receive the following error message during a query using the SQL Workbench/J client: Error:current transaction is aborted,commands ignored until end of transaction block.
    A: Select the Autocommit check box in the client.