Examples with Expression com.facebook.presto.sql.tree.Expression used on opensource projects

Example 81 with Expression

use of com.facebook.presto.sql.tree.Expression in project presto by prestodb.

the class EffectivePredicateExtractor method pullExpressionThroughSymbols.

private static Expression pullExpressionThroughSymbols(Expression expression, Collection<Symbol> symbols) {
    EqualityInference equalityInference = createEqualityInference(expression);
    ImmutableList.Builder<Expression> effectiveConjuncts = ImmutableList.builder();
    for (Expression conjunct : EqualityInference.nonInferrableConjuncts(expression)) {
        if (DeterminismEvaluator.isDeterministic(conjunct)) {
            Expression rewritten = equalityInference.rewriteExpression(conjunct, in(symbols));
            if (rewritten != null) {
                effectiveConjuncts.add(rewritten);
            }
        }
    }
    effectiveConjuncts.addAll(equalityInference.generateEqualitiesPartitionedBy(in(symbols)).getScopeEqualities());
    return combineConjuncts(effectiveConjuncts.build());
}

Example 82 with Expression

use of com.facebook.presto.sql.tree.Expression in project presto by prestodb.

the class EffectivePredicateExtractor method visitJoin.

@Override
public Expression visitJoin(JoinNode node, Void context) {
    Expression leftPredicate = node.getLeft().accept(this, context);
    Expression rightPredicate = node.getRight().accept(this, context);
    List<Expression> joinConjuncts = new ArrayList<>();
    for (JoinNode.EquiJoinClause clause : node.getCriteria()) {
        joinConjuncts.add(new ComparisonExpression(ComparisonExpressionType.EQUAL, clause.getLeft().toSymbolReference(), clause.getRight().toSymbolReference()));
    }
    switch(node.getType()) {
        case INNER:
            return combineConjuncts(ImmutableList.<Expression>builder().add(pullExpressionThroughSymbols(leftPredicate, node.getOutputSymbols())).add(pullExpressionThroughSymbols(rightPredicate, node.getOutputSymbols())).addAll(pullExpressionsThroughSymbols(joinConjuncts, node.getOutputSymbols())).build());
        case LEFT:
            return combineConjuncts(ImmutableList.<Expression>builder().add(pullExpressionThroughSymbols(leftPredicate, node.getOutputSymbols())).addAll(pullNullableConjunctsThroughOuterJoin(extractConjuncts(rightPredicate), node.getOutputSymbols(), node.getRight().getOutputSymbols()::contains)).addAll(pullNullableConjunctsThroughOuterJoin(joinConjuncts, node.getOutputSymbols(), node.getRight().getOutputSymbols()::contains)).build());
        case RIGHT:
            return combineConjuncts(ImmutableList.<Expression>builder().add(pullExpressionThroughSymbols(rightPredicate, node.getOutputSymbols())).addAll(pullNullableConjunctsThroughOuterJoin(extractConjuncts(leftPredicate), node.getOutputSymbols(), node.getLeft().getOutputSymbols()::contains)).addAll(pullNullableConjunctsThroughOuterJoin(joinConjuncts, node.getOutputSymbols(), node.getLeft().getOutputSymbols()::contains)).build());
        case FULL:
            return combineConjuncts(ImmutableList.<Expression>builder().addAll(pullNullableConjunctsThroughOuterJoin(extractConjuncts(leftPredicate), node.getOutputSymbols(), node.getLeft().getOutputSymbols()::contains)).addAll(pullNullableConjunctsThroughOuterJoin(extractConjuncts(rightPredicate), node.getOutputSymbols(), node.getRight().getOutputSymbols()::contains)).addAll(pullNullableConjunctsThroughOuterJoin(joinConjuncts, node.getOutputSymbols(), node.getLeft().getOutputSymbols()::contains, node.getRight().getOutputSymbols()::contains)).build());
        default:
            throw new UnsupportedOperationException("Unknown join type: " + node.getType());
    }
}

Example 83 with Expression

use of com.facebook.presto.sql.tree.Expression in project presto by prestodb.

the class EffectivePredicateExtractor method visitFilter.

@Override
public Expression visitFilter(FilterNode node, Void context) {
    Expression underlyingPredicate = node.getSource().accept(this, context);
    Expression predicate = node.getPredicate();
    // Remove non-deterministic conjuncts
    predicate = stripNonDeterministicConjuncts(predicate);
    return combineConjuncts(predicate, underlyingPredicate);
}

Example 84 with Expression

use of com.facebook.presto.sql.tree.Expression in project presto by prestodb.

the class EqualityInference method rewriteExpression.

private Expression rewriteExpression(Expression expression, Predicate<Symbol> symbolScope, boolean allowFullReplacement) {
    Iterable<Expression> subExpressions = SubExpressionExtractor.extract(expression);
    if (!allowFullReplacement) {
        subExpressions = filter(subExpressions, not(equalTo(expression)));
    }
    ImmutableMap.Builder<Expression, Expression> expressionRemap = ImmutableMap.builder();
    for (Expression subExpression : subExpressions) {
        Expression canonical = getScopedCanonical(subExpression, symbolScope);
        if (canonical != null) {
            expressionRemap.put(subExpression, canonical);
        }
    }
    // Perform a naive single-pass traversal to try to rewrite non-compliant portions of the tree. Prefers to replace
    // larger subtrees over smaller subtrees
    // TODO: this rewrite can probably be made more sophisticated
    Expression rewritten = ExpressionTreeRewriter.rewriteWith(new ExpressionNodeInliner(expressionRemap.build()), expression);
    if (!symbolToExpressionPredicate(symbolScope).apply(rewritten)) {
        // If the rewritten is still not compliant with the symbol scope, just give up
        return null;
    }
    return rewritten;
}

Example 85 with Expression

use of com.facebook.presto.sql.tree.Expression in project presto by prestodb.

the class ExpressionInterpreter method evaluateConstantExpression.

public static Object evaluateConstantExpression(Expression expression, Type expectedType, Metadata metadata, Session session, List<Expression> parameters) {
    ExpressionAnalyzer analyzer = createConstantAnalyzer(metadata, session, parameters);
    analyzer.analyze(expression, Scope.builder().build());
    Type actualType = analyzer.getExpressionTypes().get(expression);
    if (!metadata.getTypeManager().canCoerce(actualType, expectedType)) {
        throw new SemanticException(SemanticErrorCode.TYPE_MISMATCH, expression, String.format("Cannot cast type %s to %s", expectedType.getTypeSignature(), actualType.getTypeSignature()));
    }
    IdentityLinkedHashMap<Expression, Type> coercions = new IdentityLinkedHashMap<>();
    coercions.putAll(analyzer.getExpressionCoercions());
    coercions.put(expression, expectedType);
    return evaluateConstantExpression(expression, coercions, metadata, session, ImmutableSet.of(), parameters);
}