Sequence File: Intro
Explore the role of sequence files in Hadoop as an efficient binary format for storing key-value pairs and small files. Understand their structure, including headers, records, and sync markers, along with compression options like record and block compression. This lesson helps you grasp how sequence files optimize storage and processing in the Hadoop ecosystem.
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Sequence File: Intro
Apart from supporting text formats, Hadoop also supports binary formats. The sequence file is one of them. Binary data takes up less disk space than textual data. The temporary data output by map tasks is stored as sequence files.
One of the problems Hadoop faces is storing lots of small files. The Namenode runs short on memory if the system has too many small files. Similarly, if the input to a map-reduce job consists of numerous small files, then the number of mapper tasks (one per file) will be significantly more than if there were fewer, larger files. To overcome these issues, ...