A “plan diagram” is a pictorial enumeration of the execution plan choices of a database query optimizer over the relational selectivity space. In this paper, we present and an...
Estimates of predicate selectivities by database query optimizers often differ significantly from those actually encountered during query execution, leading to poor plan choices a...
A "plan diagram" is a pictorial enumeration of the execution plan choices of a database query optimizer over the relational selectivity space. We have shown recently tha...
Query optimizers normally compile queries into one optimal plan by assuming complete knowledge of all cost parameters such asselectivity and resourceavailability. The execution of...