Stream - Query Optimizer

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1 - About

2 - 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.
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3 - Documentation / Reference

data/processing/stream/query_optimizer.txt · Last modified: 2017/09/13 20:04 by gerardnico