public class ASTServiceNodeOptimizer extends Object implements IASTOptimizer
ServiceNodes into a named subquery. Recursively rewrites the WHERE clause of any named subquery such that there is no more than one
ServiceNodein that subquery by lifting out additional
ServiceNodes into new named subqueries.
Note: This rewrite step is useful when it is desirable to run the service
once (it is also possible to annotate the
ServiceCall operator as
By default, if a
ServiceNode appears in any position other than the
head of a
NamedSubqueryRoot, then it will be invoked once for each
chunk of solutions which flows through that part of the query plan.
BD#SEARCH. It may well be that we want to take this out entirely. Our internal search service runs well when lifted out. However, it might run just as well if we specified it as an "at-once" operator.
|Constructor and Description|
|Modifier and Type||Method and Description|
Optimize the AST.
public QueryNodeWithBindingSet optimize(AST2BOpContext context, QueryNodeWithBindingSet input)
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