Book Image

Learning HBase

By : Shashwat Shriparv
Book Image

Learning HBase

By: Shashwat Shriparv

Overview of this book

Table of Contents (18 chapters)
Learning HBase
Credits
About the Author
Acknowledgments
About the Reviewers
www.PacktPub.com
Preface
Index

Storing data in HBase – logical view versus actual physical view


At a conceptual level, an HBase table can be seen as a sparse set of rows, but in actual storage, it is stored as per a column family. While defining a table, columns can be added or specified on the run in a column family. We must decide the number and name of the column family at the time of table creation, but columns can be added as required at any point in time while storing the data, and this is the beauty of schema-free when we use HBase.

The following is the logical view of how data is stored in HBase, but in actual these are stored separately with column families:

Row keys

Time_Stamp

Column family 1 (CF1)

Column family 2 (CF2)

 

CF1:Col 1

CF1:Col 2

CF2:Col 3

CF2:Col4

CF2:Col 5

Row1

Time stamp 1

  

Value 3

Value 4

Value 5

Row2

Time stamp 2

Value 6

Value 7

Value 8

Value 9

Value 10

Row2

Time stamp 3

Value 11

Value 12

Value 13

  

So, in physical storage, this table will be stored in two parts...