Compression

The LZO compression format is composed of approximately __________ blocks of compressed data. a) 128k b) 256k c) 24k d) 36k

b) 256k LZO was designed with speed in mind: it decompresses about twice as fast as gzip, meaning it's fast enough to keep up with hard drive read speeds.

Point out the correct statement : a) Snappy is licensed under the GNU Public License (GPL) b) BgCIK needs to create an index when it compresses a file c) The Snappy codec is integrated into Hadoop Common, a set of common utilities that supports other Hadoop subprojects d) None of the mentioned

c) The Snappy codec is integrated into Hadoop Common, a set of common utilities that supports other Hadoop subprojects You can use Snappy as an add-on for more recent versions of Hadoop that do not yet provide Snappy codec support.

Point out the wrong statement: a) From a usability standpoint, LZO and Gzip are similar. b) Bzip2 generates a better compression ratio than does Gzip, but it's much slower c) Gzip is a compression utility that was adopted by the GNU project d) None of the mentioned

a) From a usability standpoint, LZO and Gzip are similar. From a usability standpoint, Bzip2 and Gzip are similar.

Which of the following supports splittable compression? a) LZO b) Bzip2 c) Gzip d) All of the mentioned

a) LZO LZO enables the parallel processing of compressed text file splits by your MapReduce jobs.

Which of the following compression is similar to Snappy compression? a) LZO b) Bzip2 c) Gzip d) All of the mentioned

a) LZO LZO is only really desirable if you need to compress text files.

Gzip (short for GNU zip) generates compressed files that have a _________ extension. a) .gzip b) .gz c) .gzp d) .g

b) .gz You can use the gunzip command to decompress files that were created by a number of compression utilities, including Gzip.

Which of the following is the slowest compression technique? a) LZO b) Bzip2 c) Gzip d) All of the mentioned

b) Bzip2 Of all the available compression codecs in Hadoop, Bzip2 is by far the slowest.

__________ typically compresses files to within 10% to 15% of the best available techniques. a) LZO b) Bzip2 c) Gzip d) All of the mentioned

b) Bzip2 bzip2 is a freely available, patent free (see below), high-quality data compressor.

The _________ codec from Google provides modest compression ratios. a) Snapcheck b) Snappy c) FileCompress d) None of the mentioned

b) Snappy Snappy has fast compression and decompression speeds.

Which of the following is based on the DEFLATE algorithm? a) LZO b) Bzip2 c) Gzip d) All of the mentioned

c) Gzip gzip is based on the DEFLATE algorithm, which is a combination of LZ77 and Huffman Coding.