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PrunedFilteredScan Contract — Relations with Column Pruning and Filter Pushdown

PrunedFilteredScan Contract — Relations with Column Pruning and Filter Pushdown

PrunedFilteredScan is the contract of BaseRelations with support for column pruning (i.e. eliminating unneeded columns) and filter pushdown (i.e. filtering using selected predicates only).

Table 1. PrunedFilteredScan Contract
Property Description

buildScan

Building distributed data scan with column pruning and filter pushdown

In other words, buildScan creates a RDD[Row] to represent a distributed data scan (i.e. scanning over data in a relation)

Used exclusively when DataSourceStrategy execution planning strategy is requested to plan a LogicalRelation with a PrunedFilteredScan.

Note
PrunedFilteredScan is a “lighter” and stable version of the CatalystScan Contract.
Note
JDBCRelation is the one and only known implementation of the PrunedFilteredScan Contract in Spark SQL.

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