Default File Formats

To improve useability and functionality, Impala significantly changed table creation. In CDP, the default file format of the tables is Parquet.

New Default Behavior

When you issue the CREATE TABLE statement without the STORED AS clause, Impala creates a Parquet table instead of a Text table as in CDH.

For example, if you create an external table based on a text file without providing the STORED AS clause and then issue a select query, the query fails in CDP, because Impala expects the file to be in the Parquet file format.

Steps to switch to the CDH behavior:

Add the explicitly stored as clause to in the CREATE TABLE statements if the file format is not Parquet.
Start Coordinator with the default_transactional_type flag set to text for all tables.
Set the default_file_format query option to TEXT to revert to the default Text format for one or more CREATE TABLE statements.

For more information on transactions supported by Impala, see SQL transactions in Impala