Challenges with Previous Technologies
- Relational databases were the standard for years, so what changed? With more and more data came the need to scale. However relational databases were designed for a single node. They were not designed to be run on clusters.
- With a relational database, you normalize your schema, which eliminates redundant data and makes storage efficient. Indexes and queries with joins are used to bring the data back together again. Indexes slow down data ingestion with lots of nonsequential disk I/O, and joins cause bottlenecks on reads with lots of data. The relational model does not scale horizontally across a cluster.