Examples with QueryPlanTranslator com.yahoo.elide.datastores.aggregation.queryengines.sql.query.QueryPlanTranslator used on opensource projects

Example 1 with QueryPlanTranslator

use of com.yahoo.elide.datastores.aggregation.queryengines.sql.query.QueryPlanTranslator in project elide by yahoo.

the class SQLQueryEngine method expandMetricQueryPlans.

/**
 * Transforms a client query into a potentially nested/complex query by expanding each metric into
 * its respective query plan - and then merging the plans together into a consolidated query.
 * @param query The client query.
 * @return A query that reflects each metric's individual query plan.
 */
private Query expandMetricQueryPlans(Query query) {
    // Expand each metric into its own query plan.
    List<QueryPlan> toMerge = query.getMetricProjections().stream().map(projection -> projection.resolve(query)).collect(Collectors.toList());
    // Merge all the queries together.
    List<QueryPlan> mergedPlans = merger.merge(toMerge);
    // TODO - Support joins across plans rather than rejecting plans that don't merge.
    if (mergedPlans.size() != 1) {
        throw new UnsupportedOperationException("Incompatible metrics in client query.  Cannot merge " + "into a single query");
    }
    QueryPlan mergedPlan = mergedPlans.get(0);
    QueryPlanTranslator queryPlanTranslator = new QueryPlanTranslator(query, metaDataStore, merger);
    Query merged = (mergedPlan == null) ? QueryPlanTranslator.addHiddenProjections(metaDataStore, query).build() : queryPlanTranslator.translate(mergedPlan);
    for (Optimizer optimizer : optimizers) {
        SQLTable table = (SQLTable) query.getSource();
        // override table hints.
        if (table.getHints().contains(optimizer.negateHint())) {
            continue;
        }
        if (!table.getHints().contains(optimizer.hint())) {
            continue;
        }
        if (optimizer.canOptimize(merged)) {
            merged = optimizer.optimize(merged);
        }
    }
    return merged;
}