The most important thing to know in Cassandra data modeling: The primary key

The article discusses primary key selection and usage in Apache Cassandra, a distributed database system. It explains that unlike relational databases, Cassandra does not support JOIN operations, so data models must be designed with specific queries and access patterns in mind. The basic primary key is a single parameter identifying a record, while complex primary keys consist of multiple clustering columns that determine the order of data within partitions. The CLUSTERING ORDER BY clause allows for default sorting of clustering columns at table creation time, enabling efficient queries on time series data models. Understanding primary key components is crucial for effective Cassandra data modeling and can help prevent common mistakes like using only one partition key.