Examples with RowExpressionDeterminismEvaluator com.facebook.presto.sql.relational.RowExpressionDeterminismEvaluator used on opensource projects

Example 11 with RowExpressionDeterminismEvaluator

use of com.facebook.presto.sql.relational.RowExpressionDeterminismEvaluator in project presto by prestodb.

the class SortExpressionExtractor method extractSortExpression.

public static Optional<SortExpressionContext> extractSortExpression(Set<VariableReferenceExpression> buildVariables, RowExpression filter, FunctionAndTypeManager functionAndTypeManager) {
    List<RowExpression> filterConjuncts = LogicalRowExpressions.extractConjuncts(filter);
    SortExpressionVisitor visitor = new SortExpressionVisitor(buildVariables, functionAndTypeManager);
    DeterminismEvaluator determinismEvaluator = new RowExpressionDeterminismEvaluator(functionAndTypeManager);
    List<SortExpressionContext> sortExpressionCandidates = filterConjuncts.stream().filter(determinismEvaluator::isDeterministic).map(conjunct -> conjunct.accept(visitor, null)).filter(Optional::isPresent).map(Optional::get).collect(toMap(SortExpressionContext::getSortExpression, identity(), SortExpressionExtractor::merge)).values().stream().collect(toImmutableList());
    // TODO: make it cost based decision based on symbol statistics
    return sortExpressionCandidates.stream().sorted(comparing(context -> -1 * context.getSearchExpressions().size())).findFirst();
}