Advanced Impala Concepts - Learning Cloudera Impala - page 151

File formats and compression types

supported in Impala

Hadoop is used as a data storage system where all kinds of data is stored in various
file formats. To reduce the disk space requirement, the data is stored in a compressed
format so various compression types are used with different kinds of file formats. Vari-
ous file formats and compression types create a collection of file formats and com-
pression combinations for any application to support.

Impala does a great job in supporting most of the popular file formats and compres-
sion types, as listed in the following table:

File type Compression type CREATE support INSERT support

Text LZO Yes Yes

Avro GZIP, BZIP2, deflate, Snappy No (use Hive) No

RCFile GZIP, BZIP2, deflate, Snappy Yes No

SequenceFile GZIP, BZIP2, deflate, Snappy Yes No

Parquet GZIP, Snappy (default) Yes Yes

The preceding table also describes if Impala can use the CREATE or INSERT com-
mand with specific file and compression types. For example, with the Parquet file type
and the Snappy or GZIP compression type, Impala can create tables as well as in-