Examples with PlanItem org.h2.table.PlanItem used on opensource projects

Example 6 with PlanItem

use of org.h2.table.PlanItem in project h2database by h2database.

the class TableView method getBestPlanItem.

@Override
public PlanItem getBestPlanItem(Session session, int[] masks, TableFilter[] filters, int filter, SortOrder sortOrder, HashSet<Column> allColumnsSet) {
    final CacheKey cacheKey = new CacheKey(masks, this);
    Map<Object, ViewIndex> indexCache = session.getViewIndexCache(topQuery != null);
    ViewIndex i = indexCache.get(cacheKey);
    if (i == null || i.isExpired()) {
        i = new ViewIndex(this, index, session, masks, filters, filter, sortOrder);
        indexCache.put(cacheKey, i);
    }
    PlanItem item = new PlanItem();
    item.cost = i.getCost(session, masks, filters, filter, sortOrder, allColumnsSet);
    item.setIndex(i);
    return item;
}

Example 7 with PlanItem

use of org.h2.table.PlanItem in project h2database by h2database.

the class Plan method calculateCost.

/**
 * Calculate the cost of this query plan.
 *
 * @param session the session
 * @return the cost
 */
public double calculateCost(Session session) {
    Trace t = session.getTrace();
    if (t.isDebugEnabled()) {
        t.debug("Plan       : calculate cost for plan {0}", Arrays.toString(allFilters));
    }
    double cost = 1;
    boolean invalidPlan = false;
    final HashSet<Column> allColumnsSet = ExpressionVisitor.allColumnsForTableFilters(allFilters);
    for (int i = 0; i < allFilters.length; i++) {
        TableFilter tableFilter = allFilters[i];
        if (t.isDebugEnabled()) {
            t.debug("Plan       :   for table filter {0}", tableFilter);
        }
        PlanItem item = tableFilter.getBestPlanItem(session, allFilters, i, allColumnsSet);
        planItems.put(tableFilter, item);
        if (t.isDebugEnabled()) {
            t.debug("Plan       :   best plan item cost {0} index {1}", item.cost, item.getIndex().getPlanSQL());
        }
        cost += cost * item.cost;
        setEvaluatable(tableFilter, true);
        Expression on = tableFilter.getJoinCondition();
        if (on != null) {
            if (!on.isEverything(ExpressionVisitor.EVALUATABLE_VISITOR)) {
                invalidPlan = true;
                break;
            }
        }
    }
    if (invalidPlan) {
        cost = Double.POSITIVE_INFINITY;
    }
    if (t.isDebugEnabled()) {
        session.getTrace().debug("Plan       : plan cost {0}", cost);
    }
    for (TableFilter f : allFilters) {
        setEvaluatable(f, false);
    }
    return cost;
}

Example 8 with PlanItem

use of org.h2.table.PlanItem in project h2database by h2database.

the class Table method getBestPlanItem.

/**
 * Get the best plan for the given search mask.
 *
 * @param session the session
 * @param masks per-column comparison bit masks, null means 'always false',
 *              see constants in IndexCondition
 * @param filters all joined table filters
 * @param filter the current table filter index
 * @param sortOrder the sort order
 * @param allColumnsSet the set of all columns
 * @return the plan item
 */
public PlanItem getBestPlanItem(Session session, int[] masks, TableFilter[] filters, int filter, SortOrder sortOrder, HashSet<Column> allColumnsSet) {
    PlanItem item = new PlanItem();
    item.setIndex(getScanIndex(session));
    item.cost = item.getIndex().getCost(session, null, filters, filter, null, allColumnsSet);
    Trace t = session.getTrace();
    if (t.isDebugEnabled()) {
        t.debug("Table      :     potential plan item cost {0} index {1}", item.cost, item.getIndex().getPlanSQL());
    }
    ArrayList<Index> indexes = getIndexes();
    IndexHints indexHints = getIndexHints(filters, filter);
    if (indexes != null && masks != null) {
        for (int i = 1, size = indexes.size(); i < size; i++) {
            Index index = indexes.get(i);
            if (isIndexExcludedByHints(indexHints, index)) {
                continue;
            }
            double cost = index.getCost(session, masks, filters, filter, sortOrder, allColumnsSet);
            if (t.isDebugEnabled()) {
                t.debug("Table      :     potential plan item cost {0} index {1}", cost, index.getPlanSQL());
            }
            if (cost < item.cost) {
                item.cost = cost;
                item.setIndex(index);
            }
        }
    }
    return item;
}