org.apache.hadoop.hive.ql.optimizer
Interface Transform
- All Known Implementing Classes:
- ColumnPruner, UnionProcessor
public interface Transform
Optimizer interface. All the rule-based optimizations implement this interface. All the transformations are invoked sequentially. They take the current
parse context (which contains the operator tree among other things), perform all the optimizations, and then return the updated parse context.
transform
ParseContext transform(ParseContext pctx)
throws SemanticException
- All transformation steps implement this interface
- Parameters:
pctx
- input parse context
- Returns:
- ParseContext
- Throws:
SemanticException
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