Stream Data Management Systems
Makes one addition to the relational model
- stream = infinite sequence of tuples, arriving one-at-a-time
Applications: news feeds, telecomms, monitoring web usage, ...
RDBMSs: run a variety of queries on (relatively) fixed data
StreamDBs: run fixed queries on changing data (stream)
One approach: window = "relation" formed from a stream via a rule
E.g. StreamSQL
select avg(price)
from examplestream [size 10 advance 1 tuples]
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