Impala : argument of type 'NoneType' is not iterable
I have imported a table from MySQL which has 10 million rows to Hive and now performing some operations in Impala to check the functionality and performance. Now I am getting an error argument of type 'NoneType' is not iterable when I issue the following query.
select count(id) from my_table_name;
Is there anything I need to do after importing the data to fix this ? I am intended to use Impala mainly for analytics purpose and so it involves lot of SUM and COUNT functions.
Try using the refresh command. Here is a reference from Cloudera docs:
REFRESH [db_name.]table_name Usage notes:
Use the REFRESH statement to load the latest metastore metadata and block location data for a particular table in these scenarios:
After loading new data files into the HDFS data directory for the table. (Once you have set up an ETL pipeline to bring data into Impala on a regular basis, this is typically the most frequent reason why metadata needs to be refreshed.) After issuing ALTER TABLE, INSERT, LOAD DATA, or other table-modifying SQL statement in Hive.