[teiid-issues] [JBoss JIRA] (TEIID-3454) Dependent Join optimizations for Netezza and Hive

Dependent Join optimizations for Netezza and Hive ------------------------------------------------- Key: TEIID-3454 URL: https://issues.jboss.org/browse/TEIID-3454 Project: Teiid Issue Type: Feature Request Components: Query Engine Affects Versions: 8.10 Reporter: John Muller Assignee: Steven Hawkins Priority: Minor Fix For: 9.1 Currently, dependent joins create 1 or more IN clauses. Many MPP / NoSQL systems can have drastically better performance by creating temp tables that match key distributions. Two examples I know of would be Netezza and Hive. In Netezza, if the incoming dependent join (small dimension; here "Customer" using Northwind data model concepts) has a key that will be joined to to a big fact table that is DISTRIBUTED ON or ORGANIZED BY 'ed then creating a temp table that matches this distribution will result in ~100x query performance. Sometimes, if the dimension is small enough, this doesn't make a big difference as Netezza will perform a broadcast join, but it's never a bad idea to create the temp table. Similarly, Hive DDL has both partitions and buckets (pre-sorted).