Migrating SQL applications to Cassandra – Pattern #3

Pattern #3: Get rid of all NOT operators from sql where clauses. For example, consider a typical SQL query to find all employees who have NOT completed a mandatory information security training: select ee1.* from employee ee1 where NOT exists (     select ‘true’ from employee_training et1     where et1.employeeID = ee1.employeeID     and … Continue reading Migrating SQL applications to Cassandra – Pattern #3

Migrating SQL applications to Cassandra – Pattern #2

Pattern #2: Get rid of all EXISTS and IN from sql where clauses. For example, consider a typical SQL query to find all employees who have completed a mandatory information security training: select ee1.* from employee ee1 where exists (     select 'true' from employee_training et1     where et1.employeeID = ee1.employeeID     and … Continue reading Migrating SQL applications to Cassandra – Pattern #2

Ohioedge 2.0 Architecture

Ohioedge 2.0 is a linearly scalable, no single point of failure (SPOF) architecture built using Cassandra, Zookeeper and Kafka. In addition, Ohioedge document component uses pithos.io service to save/retrieve documents from the underlying Cassandra data store. At the core of Ohioedge is a schema-driven request-to-response transformation engine - Ohioedge Builder. Out-of-the-box it enables CRUD and relationship … Continue reading Ohioedge 2.0 Architecture