Examples with SymbolToTrueVisitor io.crate.analyze.SymbolToTrueVisitor used on opensource projects

Example 1 with SymbolToTrueVisitor

use of io.crate.analyze.SymbolToTrueVisitor in project crate by crate.

the class WhereClauseAnalyzer method tieBreakPartitionQueries.

private static WhereClause tieBreakPartitionQueries(EvaluatingNormalizer normalizer, Map<Symbol, List<Literal>> queryPartitionMap, WhereClause whereClause, TransactionContext transactionContext) throws UnsupportedOperationException {
    /*
         * Got multiple normalized queries which all could match.
         * This might be the case if one partition resolved to null
         *
         * e.g.
         *
         *  p = 1 and x = 2
         *
         * might lead to
         *
         *  null and x = 2
         *  true and x = 2
         *
         * At this point it is unknown if they really match.
         * In order to figure out if they could potentially match all conditions involving references are now set to true
         *
         *  null and true   -> can't match
         *  true and true   -> can match, can use this query + partition
         *
         * If there is still more than 1 query that can match it's not possible to execute the query :(
         */
    List<Tuple<Symbol, List<Literal>>> canMatch = new ArrayList<>();
    SymbolToTrueVisitor symbolToTrueVisitor = new SymbolToTrueVisitor();
    for (Map.Entry<Symbol, List<Literal>> entry : queryPartitionMap.entrySet()) {
        Symbol query = entry.getKey();
        List<Literal> partitions = entry.getValue();
        Symbol symbol = symbolToTrueVisitor.process(query, null);
        Symbol normalized = normalizer.normalize(symbol, transactionContext);
        assert normalized instanceof Literal : "after normalization and replacing all reference occurrences with true there must only be a literal left";
        Object value = ((Literal) normalized).value();
        if (value != null && (Boolean) value) {
            canMatch.add(new Tuple<>(query, partitions));
        }
    }
    if (canMatch.size() == 1) {
        Tuple<Symbol, List<Literal>> symbolListTuple = canMatch.get(0);
        WhereClause where = new WhereClause(symbolListTuple.v1(), whereClause.docKeys().orElse(null), new ArrayList<String>(symbolListTuple.v2().size()));
        where.partitions(symbolListTuple.v2());
        return where;
    }
    throw new UnsupportedOperationException("logical conjunction of the conditions in the WHERE clause which " + "involve partitioned columns led to a query that can't be executed.");
}