I am running a CDH distribution (version 5.6.0) with Impala (version 2.4.0).

I have some Parquet files stored in HDFS. Next, I have loaded these files into an Impala external table. Upon executing the following query all the files are successfully listed:

[cloudera-impala-dn0.eastus.cloudapp.azure.com:21000] > show files in parquettable;

Also, the metadata is correct (checked by executing describe parquettable).

The stats of the table are:

[cloudera-impala-dn0.eastus.cloudapp.azure.com:21000] > show table stats parquettable;

Rows | Files | Size | Bytes Cached | Cache Replication | Format | Incremental stats | Location

-1 | 838 | 249.64GB | NOT CACHED | NOT CACHED | PARQUET | false | hdfs://cloudera-impala-mn0.eastus.cloudapp.azure.com:8020/user/root/big_data

Executing the following query:

[cloudera-impala-dn0.eastus.cloudapp.azure.com:21000] > select count(*) from parquettable;

results in the following WARNING, but without any output result or error:

File 'hdfs://cloudera-impala-mn0.eastus.cloudapp.azure.com:8020/user/root/big_data/part-r-00001-7c29b85c-bd1f-420e-8834-96300076a92d.gz.parquet' has an invalid version number: ▒.F/ This could be due to stale metadata. Try running "refresh default.parquettable".

Running refresh default.parquettable did not have any effect.