public class ASTRunFirstRunLastOptimizer extends Object implements IASTOptimizer
JoinGroupNodein the right order w.r.t. to the other types.
Basically the ASTRunFirstRunLastOptimizer will look for IJoinNodes that have a query hint of QueryHints.RUN_FIRST=true or RUN_LAST=true. If it finds more than one "run first" or "run last" it will throw an exception. If it finds an optional marked as "run first" it will throw an exception. It will then scan the group and identify the first and last indices for IJoinNodes, and place the run first and run last IJoinNodes at those indices. The static optimizer will also look for a "run first" IJoinNode in a group and make sure that it gets run first in the group (of the statement patterns).
|Constructor and Description|
|Modifier and Type||Method and Description|
Optimize the AST.
public IQueryNode optimize(AST2BOpContext context, IQueryNode queryNode, IBindingSet bindingSets)
Copyright © 2006-2015 SYSTAP, LLC. All Rights Reserved.