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

Example 11 with TableFilter

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

the class Optimizer method shuffleTwo.

private boolean shuffleTwo(TableFilter[] f) {
    int a = 0, b = 0, i = 0;
    for (; i < 20; i++) {
        a = random.nextInt(f.length);
        b = random.nextInt(f.length);
        if (a == b) {
            continue;
        }
        if (a < b) {
            int temp = a;
            a = b;
            b = temp;
        }
        int s = a * f.length + b;
        if (switched.get(s)) {
            continue;
        }
        switched.set(s);
        break;
    }
    if (i == 20) {
        return false;
    }
    TableFilter temp = f[a];
    f[a] = f[b];
    f[b] = temp;
    return true;
}

Example 12 with TableFilter

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

the class Select method expandColumnList.

private void expandColumnList() {
    Database db = session.getDatabase();
    // the expressions may change within the loop
    for (int i = 0; i < expressions.size(); i++) {
        Expression expr = expressions.get(i);
        if (!expr.isWildcard()) {
            continue;
        }
        String schemaName = expr.getSchemaName();
        String tableAlias = expr.getTableAlias();
        if (tableAlias == null) {
            expressions.remove(i);
            for (TableFilter filter : filters) {
                i = expandColumnList(filter, i);
            }
            i--;
        } else {
            TableFilter filter = null;
            for (TableFilter f : filters) {
                if (db.equalsIdentifiers(tableAlias, f.getTableAlias())) {
                    if (schemaName == null || db.equalsIdentifiers(schemaName, f.getSchemaName())) {
                        filter = f;
                        break;
                    }
                }
            }
            if (filter == null) {
                throw DbException.get(ErrorCode.TABLE_OR_VIEW_NOT_FOUND_1, tableAlias);
            }
            expressions.remove(i);
            i = expandColumnList(filter, i);
            i--;
        }
    }
}

Example 13 with TableFilter

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

the class Select method prepare.

@Override
public void prepare() {
    if (isPrepared) {
        // sometimes a subquery is prepared twice (CREATE TABLE AS SELECT)
        return;
    }
    if (SysProperties.CHECK && !checkInit) {
        DbException.throwInternalError("not initialized");
    }
    if (orderList != null) {
        sort = prepareOrder(orderList, expressions.size());
        orderList = null;
    }
    ColumnNamer columnNamer = new ColumnNamer(session);
    for (int i = 0; i < expressions.size(); i++) {
        Expression e = expressions.get(i);
        String proposedColumnName = e.getAlias();
        String columnName = columnNamer.getColumnName(e, i, proposedColumnName);
        // if the name changed, create an alias
        if (!columnName.equals(proposedColumnName)) {
            e = new Alias(e, columnName, true);
        }
        expressions.set(i, e.optimize(session));
    }
    if (condition != null) {
        condition = condition.optimize(session);
        for (TableFilter f : filters) {
            // left outer join child on p = pc where c is null;
            if (!f.isJoinOuter() && !f.isJoinOuterIndirect()) {
                condition.createIndexConditions(session, f);
            }
        }
    }
    if (isGroupQuery && groupIndex == null && havingIndex < 0 && filters.size() == 1) {
        if (condition == null) {
            Table t = filters.get(0).getTable();
            ExpressionVisitor optimizable = ExpressionVisitor.getOptimizableVisitor(t);
            isQuickAggregateQuery = isEverything(optimizable);
        }
    }
    cost = preparePlan(session.isParsingCreateView());
    if (distinct && session.getDatabase().getSettings().optimizeDistinct && !isGroupQuery && filters.size() == 1 && expressions.size() == 1 && condition == null) {
        Expression expr = expressions.get(0);
        expr = expr.getNonAliasExpression();
        if (expr instanceof ExpressionColumn) {
            Column column = ((ExpressionColumn) expr).getColumn();
            int selectivity = column.getSelectivity();
            Index columnIndex = topTableFilter.getTable().getIndexForColumn(column, false, true);
            if (columnIndex != null && selectivity != Constants.SELECTIVITY_DEFAULT && selectivity < 20) {
                // the first column must be ascending
                boolean ascending = columnIndex.getIndexColumns()[0].sortType == SortOrder.ASCENDING;
                Index current = topTableFilter.getIndex();
                // if another index is faster
                if (columnIndex.canFindNext() && ascending && (current == null || current.getIndexType().isScan() || columnIndex == current)) {
                    IndexType type = columnIndex.getIndexType();
                    // indexes don't work
                    if (!type.isHash() && (!type.isUnique() || columnIndex.getColumns().length > 1)) {
                        topTableFilter.setIndex(columnIndex);
                        isDistinctQuery = true;
                    }
                }
            }
        }
    }
    if (sort != null && !isQuickAggregateQuery && !isGroupQuery) {
        Index index = getSortIndex();
        Index current = topTableFilter.getIndex();
        if (index != null && current != null) {
            if (current.getIndexType().isScan() || current == index) {
                topTableFilter.setIndex(index);
                if (!topTableFilter.hasInComparisons()) {
                    // in(select ...) and in(1,2,3) may return the key in
                    // another order
                    sortUsingIndex = true;
                }
            } else if (index.getIndexColumns() != null && index.getIndexColumns().length >= current.getIndexColumns().length) {
                IndexColumn[] sortColumns = index.getIndexColumns();
                IndexColumn[] currentColumns = current.getIndexColumns();
                boolean swapIndex = false;
                for (int i = 0; i < currentColumns.length; i++) {
                    if (sortColumns[i].column != currentColumns[i].column) {
                        swapIndex = false;
                        break;
                    }
                    if (sortColumns[i].sortType != currentColumns[i].sortType) {
                        swapIndex = true;
                    }
                }
                if (swapIndex) {
                    topTableFilter.setIndex(index);
                    sortUsingIndex = true;
                }
            }
        }
    }
    if (!isQuickAggregateQuery && isGroupQuery && getGroupByExpressionCount() > 0) {
        Index index = getGroupSortedIndex();
        Index current = topTableFilter.getIndex();
        if (index != null && current != null && (current.getIndexType().isScan() || current == index)) {
            topTableFilter.setIndex(index);
            isGroupSortedQuery = true;
        }
    }
    expressionArray = expressions.toArray(new Expression[0]);
    isPrepared = true;
}

Example 14 with TableFilter

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

the class Delete method prepare.

@Override
public void prepare() {
    if (condition != null) {
        condition.mapColumns(targetTableFilter, 0);
        if (sourceTableFilter != null) {
            condition.mapColumns(sourceTableFilter, 0);
        }
        condition = condition.optimize(session);
        condition.createIndexConditions(session, targetTableFilter);
    }
    TableFilter[] filters;
    if (sourceTableFilter == null) {
        filters = new TableFilter[] { targetTableFilter };
    } else {
        filters = new TableFilter[] { targetTableFilter, sourceTableFilter };
    }
    PlanItem item = targetTableFilter.getBestPlanItem(session, filters, 0, ExpressionVisitor.allColumnsForTableFilters(filters));
    targetTableFilter.setPlanItem(item);
    targetTableFilter.prepare();
}

Example 15 with TableFilter

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

the class ExpressionColumn method createIndexConditions.

@Override
public void createIndexConditions(Session session, TableFilter filter) {
    TableFilter tf = getTableFilter();
    if (filter == tf && column.getType() == Value.BOOLEAN) {
        IndexCondition cond = IndexCondition.get(Comparison.EQUAL, this, ValueExpression.get(ValueBoolean.TRUE));
        filter.addIndexCondition(cond);
    }
}