Invalidating the data store
(A table could have data spread across multiple directories, or in unexpected paths, if it uses partitioning or specifies a for a table after adding or removing files in the associated S3 data directory.
You cannot, nor should you want to ever turn it off. The system cache is used by Statamic and addons to store data for defined lengths of time, much like sessions or cookies might do on the browser side. As an example, the Image Transform feature uses this cache to store all the manipulated images and their various sizes.
Because this operation adds a delay to the next query against each table, potentially expensive for large tables with many partitions, try to avoid using this option for day-to-day operations in a production environment.
HDFS permissions: The user ID that the user, must have execute permissions for all the relevant directories holding table data.
This is a relatively expensive operation compared to the incremental metadata update done by the .
If you are not familiar with the way Impala uses metadata and how it shares the same metastore database as Hive, see Overview of Impala Metadata and the Metastore for background information.
Search for invalidating the data store:
Required after a table is created through the Hive shell, before the table is available for Impala queries.