Troubleshooting Performance

You may experience slow performance when querying large tables.

If you have a version of Apache Impala prior to version 3.4.0 installed, the following performance optimization is not possible. This is because these older versions are capped at a pagesize of 1024.

If you have Apache Impala version 3.4.0 or newer installed, follow this procedure to improve performance:

1. Set the Pagesize connection property to a comfortably high value. The default pagesize in versions 3.4.0 and later is 10000. A higher value will result in improved performance at the cost of addtional memory usage.
2. Enable result spooling by executing the following query:
   

   SET SPOOL_QUERY_RESULTS = TRUE