Single-Row and Multi-Row Partitions in Cassandra
In Cassandra, CQL(Cassandra Query Language) has two partitions as follows –
- Single-Row Partitions
- Multi-Row Partitions
Single-Row Partitions :
In Cassandra, the primary key represents a unique data partition and the clustering columns part are also helpful for data arrangement and are used to handle the data arrangement part. In Single-Row partitions, there is only a partitioning key on single column.
Example –
Let us take the Employee table having fields like Emp_id, Emp_name, Emp_email, where Emp_id is the primary key.
CREATE table Employee( Emp_id UUID, Emp_name TEXT, Emp_email TEXT, primary key(Emp_id) );
You can check the partitioning logical reference model for the above example as follows –
K - Primary key C - Clustering column S - Static column
Employee | ||
---|---|---|
Fields_name | Data Type | Key |
Emp_id | UUID | K |
Emp_name | TEXT | |
Emp_email | TEXT |
In Cassandra, the Primary key is the combination of the Partitioning key and Clustering column if any.
Primary Key = Partition Key + [Clustering Columns]
Multi-Row Partitions :
In Multi-Row partitions, partitioning key is applied on more than one single column and clustering column for arrangement or partitioning data modelling.
Example –
Let us take the Event table having fields like Event_venue, Event_year, Event_artifact, Events_title, Events_country, where Event_venue, Event_year are the primary keys and Event_artifact is the clustering column key.
CREATE table Events( Event_venue TEXT, Event_year INT, Event_artifact TEXT, Events_title TEXT, Events_country TEXT STATIC, primary key((Event_venue, Event_year), Event_artifact) );
You can check partitioning logical reference model for above example as follows –
K - Primary key C - Clustering column S - Static column
Events | ||
---|---|---|
Fields_name | Data Type | Key |
Event_venue | TEXT | K |
Event_year | INT | K |
Event_artifact | TEXT | |
Events_title | TEXT | |
Events_country | TEXT | S |
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