Module datafusion::optimizer::hash_build_probe_order

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.

Structs

HashBuildProbeOrder

BuildProbeOrder reorders the build and probe phase of hash joins. This uses the amount of rows that a datasource has. The rule optimizes the order such that the left (build) side of the join is the smallest. If the information is not available, the order stays the same, so that it could be optimized manually in a query.