Stream - Query Optimizer

About

SQL Engine - Query Optimizer (Query Optimization) in Stream

A query in a stream is called a pipeline

Join

If you're joining a stream to a table, and the table is small, then you can use a map join (aka a hash join with a small “build” side). But joining two streams is very different to joining two tables.

• First, for one thing, it is a union:

stream1 join history-of-stream2
union
history-of-stream2 join stream2

• Second, the size of the maps might be different than the “size” of the streams.

Documentation / Reference

• Rate-Based Query Optimization for Streaming Information - Stratis D. Viglas Jeffrey F. Naughton