com.bigdata.rdf.sparql.ast.IQueryNode Maven / Gradle / Ivy
package com.bigdata.rdf.sparql.ast;
import java.util.Properties;
import com.bigdata.bop.BOp;
import com.bigdata.bop.PipelineOp;
import com.bigdata.rdf.sparql.ast.eval.AST2BOpContext;
import com.bigdata.rdf.sparql.ast.eval.AST2BOpUtility;
import com.bigdata.rdf.sparql.ast.optimizers.ASTQueryHintOptimizer;
import com.bigdata.rdf.sparql.ast.optimizers.IASTOptimizer;
/**
* This is the basic interface for any AST operator that appears in the query
* plan.
*/
public interface IQueryNode extends BOp {
public interface Annotations {
/**
* An optional {@link Properties} object specifying query hints which
* apply to this AST node.
*
* The relationship between SPARQL level query hints, the annotations on
* the {@link ASTBase} and {@link PipelineOp} nodes is a bit complex,
* and this {@link Properties} object is a bit complex. Briefly, this
* {@link Properties} object contains property values which will be
* applied (copied) onto generated {@link PipelineOp}s while annotations
* on the {@link ASTBase} nodes are interpreted by {@link IASTOptimizer}
* s and {@link AST2BOpUtility}. SPARQL level query hints map into one
* or another of these things, or may directly set attributes on the
* {@link AST2BOpContext}.
*
* @see ASTQueryHintOptimizer
*/
String QUERY_HINTS = "queryHints";
}
/**
* A string representation of a recursive structure with pretty-print indent.
* @param indent
* @return
*/
String toString(final int indent);
}