Difference between revisions of "Keystone-schema-in-cassandra"
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| − | = | + | ==Some basics of schema design in Cassandra== |
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| + | Cassandra is very similar to relational databases when it comes to tables and columns. First a table has to be created along with the columns and types before data can be inserted into it. Cassandra has a query language called CQL(Cassandra query language) similar to SQL. There is a notion of partition key in Cassandra which is similar to primary key in relational database. The table is partitioned across nodes based on the hash value of the partition key in Cassandra. The primary difference between Cassandra and relational db comes in the queries that can be answered. In relational database the WHERE clause can have arbitrary column whereas in Cassandra it must have the partition key. The query could have other conditions along with the partition key in Cassandra. This is because Cassandra needs to know the partition in which the row or data resides before it can answer queries on it. | ||
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| + | The Cassandra tables for each of the backend in Keystone is described below. | ||
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| + | ===Identity=== | ||
Revision as of 07:31, 14 April 2015
Some basics of schema design in Cassandra
Cassandra is very similar to relational databases when it comes to tables and columns. First a table has to be created along with the columns and types before data can be inserted into it. Cassandra has a query language called CQL(Cassandra query language) similar to SQL. There is a notion of partition key in Cassandra which is similar to primary key in relational database. The table is partitioned across nodes based on the hash value of the partition key in Cassandra. The primary difference between Cassandra and relational db comes in the queries that can be answered. In relational database the WHERE clause can have arbitrary column whereas in Cassandra it must have the partition key. The query could have other conditions along with the partition key in Cassandra. This is because Cassandra needs to know the partition in which the row or data resides before it can answer queries on it.
The Cassandra tables for each of the backend in Keystone is described below.
