32 | Big Data Simplied
As shown in Figure 2.11, wide Column stores have tables. The tables do not belong to a data-
base and they have rows. The rows have super-columns or column families, and then columns
within them. So, the super-columns are dened when the table is dened. For the Customers
table, the super-columns are Name, Address and Orders. Then, on a row-by-row basis, the col-
umns or keys within those super-columns can be declared. So, in the above example, there is
First_Name and Last_Name within Name. Also, there is House_No and Street_Name within
Address and Last_Order_ID within Orders. On the Order side, there is a Pricing super-column,
which happens to have only one regular column in it. Also, there is an Items super-column that
has Item IDs in it.
As seen from the example, Wide Column stores or Columnar databases are not entirely
schema-free and they are semi-structured. Groups of columns known as column families or super-
columns, but not the actual columns within them, need to be defined. So, the actual columns can
differ from row to row. However, the column families or super-columns, which clearly imply a
certain category or domain of data, needs to be declared when the table is designed.
2.7.6 Hadoop Hybrids
One type of Hadoop hybrid is the combination of Hadoop with enterprise storage instead of
direct attached storage. A close comparison to that is Hadoop delivered on ready to run appli-
ances. The unique value proposition of Hadoop is that it runs on normal hardware, which also
FIGURE 2.11 Example of wide column stores
Table: Customers Table: Orders
Row ID: 101
Super Column: Name
Column: First_Name: John
Column: Second_Name: Doe
Super Column: Address
Column: House_No: 123
Column:Street_Name: Park Street
Super Column: Orders
Column: Last_Order_ID: 1701
Row ID: 1701
Super Column: Pricing
Column: Price: 1000 USD
Super Column: Items
Column: Item_ID: 2345
Column: Item_ID: 7890
Row ID: 102
Super Column: Name
Column: First_Name: Jane
Column: Second_Name: Doe
Super Column: Address
Column: House_No: 456
Column:Street_Name: Green Street
Super Column: Orders
Column: Last_Order_ID: 1702
Row ID: 1702
Super Column: Pricing
Column: Price: 700 USD
Super Column: Items
Column: Item_ID: 4321
Column: Item_ID: 5446
M02 Big Data Simplified XXXX 01.indd 32 5/10/2019 9:56:54 AM

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