optimizer

Documentation

Index

• type Optimizer
  • func New(ctx context.Context, entry *dag.Sequential, source *data.Source) *Optimizer
  • func (o *Optimizer) Entry() *dag.Sequential
  • func (o *Optimizer) OptimizeScan() error
  • func (o *Optimizer) Parallelize(n int) error

Types

type Optimizer

type Optimizer struct {
	// contains filtered or unexported fields
}

func New

func New(ctx context.Context, entry *dag.Sequential, source *data.Source) *Optimizer

func (*Optimizer) Entry

func (o *Optimizer) Entry() *dag.Sequential

func (*Optimizer) OptimizeScan

func (o *Optimizer) OptimizeScan() error

OptimizeScan transforms the DAG by attempting to lift stateless operators from the downstream sequence into the trunk of each data source in the From operator at the entry point of the DAG. Once these paths are lifted, it also attempts to move any candidate filtering operations into the source's pushdown predicate. This should be called before ParallelizeScan(). TBD: we need to do pushdown for search/cut to optimize columnar extraction.

func (*Optimizer) Parallelize

func (o *Optimizer) Parallelize(n int) error

Parallelize takes a sequential operation and tries to parallelize it by splitting as much as possible of the sequence into n parallel branches. The boolean return argument indicates whether the flowgraph could be parallelized.