Examples with QueryFeatureInspector org.apache.druid.sql.calcite.run.QueryFeatureInspector used on opensource projects

Example 1 with QueryFeatureInspector

use of org.apache.druid.sql.calcite.run.QueryFeatureInspector in project druid by druid-io.

the class DruidQuery method toScanQuery.

/**
 * Return this query as a Scan query, or null if this query is not compatible with Scan.
 *
 * @return query or null
 */
@Nullable
private ScanQuery toScanQuery(final QueryFeatureInspector queryFeatureInspector) {
    if (grouping != null) {
        // Scan cannot GROUP BY.
        return null;
    }
    if (outputRowSignature.size() == 0) {
        // Should never do a scan query without any columns that we're interested in. This is probably a planner bug.
        throw new ISE("Cannot convert to Scan query without any columns.");
    }
    final Pair<DataSource, Filtration> dataSourceFiltrationPair = getFiltration(dataSource, filter, virtualColumnRegistry);
    final DataSource newDataSource = dataSourceFiltrationPair.lhs;
    final Filtration filtration = dataSourceFiltrationPair.rhs;
    final List<ScanQuery.OrderBy> orderByColumns;
    long scanOffset = 0L;
    long scanLimit = 0L;
    if (sorting != null) {
        scanOffset = sorting.getOffsetLimit().getOffset();
        if (sorting.getOffsetLimit().hasLimit()) {
            final long limit = sorting.getOffsetLimit().getLimit();
            if (limit == 0) {
                // Can't handle zero limit (the Scan query engine would treat it as unlimited).
                return null;
            }
            scanLimit = limit;
        }
        orderByColumns = sorting.getOrderBys().stream().map(orderBy -> new ScanQuery.OrderBy(orderBy.getDimension(), orderBy.getDirection() == OrderByColumnSpec.Direction.DESCENDING ? ScanQuery.Order.DESCENDING : ScanQuery.Order.ASCENDING)).collect(Collectors.toList());
    } else {
        orderByColumns = Collections.emptyList();
    }
    if (!queryFeatureInspector.feature(QueryFeature.SCAN_CAN_ORDER_BY_NON_TIME) && (orderByColumns.size() > 1 || orderByColumns.stream().anyMatch(orderBy -> !orderBy.getColumnName().equals(ColumnHolder.TIME_COLUMN_NAME)))) {
        // Cannot handle this ordering.
        // Scan cannot ORDER BY non-time columns.
        plannerContext.setPlanningError("SQL query requires order by non-time column %s that is not supported.", orderByColumns);
        return null;
    }
    // Compute the list of columns to select, sorted and deduped.
    final SortedSet<String> scanColumns = new TreeSet<>(outputRowSignature.getColumnNames());
    orderByColumns.forEach(column -> scanColumns.add(column.getColumnName()));
    return new ScanQuery(newDataSource, filtration.getQuerySegmentSpec(), getVirtualColumns(true), ScanQuery.ResultFormat.RESULT_FORMAT_COMPACTED_LIST, 0, scanOffset, scanLimit, null, orderByColumns, filtration.getDimFilter(), ImmutableList.copyOf(scanColumns), false, ImmutableSortedMap.copyOf(plannerContext.getQueryContext()));
}