Thanks to volunteers!

1
Thanks to volunteers!

• Amit Gupta
• Arvind Hulgeri
• Aditya Phatak
• Krishna Prasad
• Jinesh Vora

2
Future Directions in Query Optimization

• Panel (the usual culprits)
• Soumen Chakrabarti, Anand Deshpande,
• Krithi Ramamritham,
• Sunita Sarawagi,
• Shridhar Shukla,
• S. Sudarshan (chair)

3
Current Scenario

• Query optimization has come a long way in the
  last two decades
• Still an area of active research
• Driving forces
• TPCD and friends -- bragging rights!
• Query optimizers are still very expensive
• Object relational DBS, Web, increasingly complex
  DSS queries, Data mining

4
Future Directions - my view

• Cost of query optimization
• exponential algorithms, scale very poorly
• can we have good approximation algorithms with
  guaranteed bounds?
• Parallel and distributed databases
• Search space is extremely large in general
• How to partition data
• How to partition operations

5
Future Directions (contd.)

• System optimization for workloads
• view and index maintenance
• query result caching
• Multi-query optimization
• Scheduling issues
• pipelining and MQO
• dealing with concurrent large queries

6
Future Directions (contd.)

• Semistructed data
• Directories, XML, etc
• Distributed query processing and the web
• Dealing with failed sites, unpredictable delays
• Alternative sources of data, site descriptions
• Querying the web
• WebSQL, WebOQL, .. (Mendelzon.., Shmueli..,
  Laks..)

7
Future Directions (contd.)

• Sources with query capabilities
• eg. SAP on top of relational DB
• SQL wrappers on top of legacy sources
• Query optimization and data mining
• beyond relational algebra?