Complex Query Plan Execution

• Focus

  • How to schedule a query with several operations optimally

• Ideas (Which is better?)

  • Right-deep plans
  • Left-deep plans
  • Bushy plans

Previous slide

Next slide

Back to first slide

View graphic version

Ideas:

Right & left are about the same if using bit vector filtering.

Bit vector filtering: use an array initialized by hashing on the 1st input & use it to find elements in the 2nd input that don’t match the 1st. -> you only end up with elements that affect the operation (see pg. 82).

Bushy has 6 or 7 problems that need to be addressed before it can be optimal.