In any database, whether it’s SQL Server, Oracle, Sybase, DB2, Access (does Access count?), or anything else, the primary bottleneck is disk IO. Even if you have an SSD, the disk is the slowest part. In those databases we use indexes to alleviate this. Their query engine uses the index to find exactly where on the disk to start and stop reading, which keeps it from scanning entire tables to find every answer.
Netezza has an entirely different solution to the IO problem (in fact, it has no indexes). It cuts the cost of disk reads by doing the work in parallel. Simply put, it’s a brute force solution to the problem using specialized hardware, but that’s just the start. (more…)