1. 1 Data Stream Management Systems Checkpoint CS240B Notes by Carlo Zaniolo UCLA CSD

2. 2 Research Challenges: from DBMS to DSMS zRelational Data Models y Relational Data Streams: same as append only relations y But plays a major role and so are timestamps— temporal DBs? y Windows as time-varying table on a data stream. zQuery Languages and Operators: y Some RA operators are no longer simple: main memory, windows, timestamps and latency, require different execution model. yBlocking operators are not for continuous queries: expressive power is further compromised y Complex aggregates with windows and slides, including UDAs, needed

3. 3 from DBMS to DSMS (cont.) zQuery Plans and Optimization: yScheduling for optimal response time, memory not for total execution cost zQuality of Services (QoS) & Approximation yLoad shedding, sampling, and other synopses—not an issue in DBMS zPrototypes and Systems: yMature technology versus very new one, but yMany research prototypes, and four startups (at least) yExtensions proposed by DBMS vendors. zAdvanced Applications: yXML and XQuery important in both yBetter support for Data Mining needed in both.