Module datafusion::optimizer [−][src]
Expand description
This module contains a query optimizer that operates against a logical plan and applies some simple rules to a logical plan, such as “Projection Push Down” and “Type Coercion”.
Modules
Utilizing exact statistics from sources to avoid scanning data
Boolean comparison rule rewrites redundant comparison expression involving boolean literal into unary expression.
Optimizer rule to replace LIMIT 0 on a plan with an empty relation.
This saves time in planning and executing the query.
Filter Push Down optimizer rule ensures that filters are applied as early as possible in the plan
Optimizer rule to switch build and probe order of hash join
based on statistics of a TableProvider. If the number of
rows of both sources is known, the order can be switched
for a faster hash join.
Optimizer rule to push down LIMIT in the query plan It will push down through projection, limits (taking the smaller limit)
Query optimizer traits
Projection Push Down optimizer rule ensures that only referenced columns are loaded into memory
Simplify expressions optimizer rule
Collection of utility functions that are leveraged by the query optimizer rules