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

Example 6 with Plan

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

the class Parser method parseDeallocate.

private DeallocateProcedure parseDeallocate() {
    readIf("PLAN");
    String procedureName = readAliasIdentifier();
    DeallocateProcedure command = new DeallocateProcedure(session);
    command.setProcedureName(procedureName);
    return command;
}

Example 7 with Plan

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

the class Explain method query.

@Override
public ResultInterface query(int maxrows) {
    Column column = new Column("PLAN", Value.STRING);
    Database db = session.getDatabase();
    ExpressionColumn expr = new ExpressionColumn(db, column);
    Expression[] expressions = { expr };
    result = new LocalResult(session, expressions, 1);
    if (maxrows >= 0) {
        String plan;
        if (executeCommand) {
            PageStore store = null;
            Store mvStore = null;
            if (db.isPersistent()) {
                store = db.getPageStore();
                if (store != null) {
                    store.statisticsStart();
                }
                mvStore = db.getMvStore();
                if (mvStore != null) {
                    mvStore.statisticsStart();
                }
            }
            if (command.isQuery()) {
                command.query(maxrows);
            } else {
                command.update();
            }
            plan = command.getPlanSQL();
            Map<String, Integer> statistics = null;
            if (store != null) {
                statistics = store.statisticsEnd();
            } else if (mvStore != null) {
                statistics = mvStore.statisticsEnd();
            }
            if (statistics != null) {
                int total = 0;
                for (Entry<String, Integer> e : statistics.entrySet()) {
                    total += e.getValue();
                }
                if (total > 0) {
                    statistics = new TreeMap<>(statistics);
                    StringBuilder buff = new StringBuilder();
                    if (statistics.size() > 1) {
                        buff.append("total: ").append(total).append('\n');
                    }
                    for (Entry<String, Integer> e : statistics.entrySet()) {
                        int value = e.getValue();
                        int percent = (int) (100L * value / total);
                        buff.append(e.getKey()).append(": ").append(value);
                        if (statistics.size() > 1) {
                            buff.append(" (").append(percent).append("%)");
                        }
                        buff.append('\n');
                    }
                    plan += "\n/*\n" + buff.toString() + "*/";
                }
            }
        } else {
            plan = command.getPlanSQL();
        }
        add(plan);
    }
    result.done();
    return result;
}

Example 8 with Plan

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

the class TableFilter method getBestPlanItem.

/**
 * Get the best plan item (index, cost) to use use for the current join
 * order.
 *
 * @param s the session
 * @param filters all joined table filters
 * @param filter the current table filter index
 * @param allColumnsSet the set of all columns
 * @return the best plan item
 */
public PlanItem getBestPlanItem(Session s, TableFilter[] filters, int filter, HashSet<Column> allColumnsSet) {
    PlanItem item1 = null;
    SortOrder sortOrder = null;
    if (select != null) {
        sortOrder = select.getSortOrder();
    }
    if (indexConditions.isEmpty()) {
        item1 = new PlanItem();
        item1.setIndex(table.getScanIndex(s, null, filters, filter, sortOrder, allColumnsSet));
        item1.cost = item1.getIndex().getCost(s, null, filters, filter, sortOrder, allColumnsSet);
    }
    int len = table.getColumns().length;
    int[] masks = new int[len];
    for (IndexCondition condition : indexConditions) {
        if (condition.isEvaluatable()) {
            if (condition.isAlwaysFalse()) {
                masks = null;
                break;
            }
            int id = condition.getColumn().getColumnId();
            if (id >= 0) {
                masks[id] |= condition.getMask(indexConditions);
            }
        }
    }
    PlanItem item = table.getBestPlanItem(s, masks, filters, filter, sortOrder, allColumnsSet);
    item.setMasks(masks);
    // The more index conditions, the earlier the table.
    // This is to ensure joins without indexes run quickly:
    // x (x.a=10); y (x.b=y.b) - see issue 113
    item.cost -= item.cost * indexConditions.size() / 100 / (filter + 1);
    if (item1 != null && item1.cost < item.cost) {
        item = item1;
    }
    if (nestedJoin != null) {
        setEvaluatable(true);
        item.setNestedJoinPlan(nestedJoin.getBestPlanItem(s, filters, filter, allColumnsSet));
        // TODO optimizer: calculate cost of a join: should use separate
        // expected row number and lookup cost
        item.cost += item.cost * item.getNestedJoinPlan().cost;
    }
    if (join != null) {
        setEvaluatable(true);
        do {
            filter++;
        } while (filters[filter] != join);
        item.setJoinPlan(join.getBestPlanItem(s, filters, filter, allColumnsSet));
        // TODO optimizer: calculate cost of a join: should use separate
        // expected row number and lookup cost
        item.cost += item.cost * item.getJoinPlan().cost;
    }
    return item;
}

Example 9 with Plan

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

the class TableFilter method getPlanSQL.

/**
 * Get the query execution plan text to use for this table filter.
 *
 * @param isJoin if this is a joined table
 * @return the SQL statement snippet
 */
public String getPlanSQL(boolean isJoin) {
    StringBuilder buff = new StringBuilder();
    if (isJoin) {
        if (joinOuter) {
            buff.append("LEFT OUTER JOIN ");
        } else {
            buff.append("INNER JOIN ");
        }
    }
    if (nestedJoin != null) {
        StringBuilder buffNested = new StringBuilder();
        TableFilter n = nestedJoin;
        do {
            buffNested.append(n.getPlanSQL(n != nestedJoin));
            buffNested.append('\n');
            n = n.getJoin();
        } while (n != null);
        String nested = buffNested.toString();
        boolean enclose = !nested.startsWith("(");
        if (enclose) {
            buff.append("(\n");
        }
        buff.append(StringUtils.indent(nested, 4, false));
        if (enclose) {
            buff.append(')');
        }
        if (isJoin) {
            buff.append(" ON ");
            if (joinCondition == null) {
                // need to have a ON expression,
                // otherwise the nesting is unclear
                buff.append("1=1");
            } else {
                buff.append(StringUtils.unEnclose(joinCondition.getSQL()));
            }
        }
        return buff.toString();
    }
    if (table.isView() && ((TableView) table).isRecursive()) {
        buff.append(table.getName());
    } else {
        buff.append(table.getSQL());
    }
    if (table.isView() && ((TableView) table).isInvalid()) {
        throw DbException.get(ErrorCode.VIEW_IS_INVALID_2, table.getName(), "not compiled");
    }
    if (alias != null) {
        buff.append(' ').append(Parser.quoteIdentifier(alias));
    }
    if (indexHints != null) {
        buff.append(" USE INDEX (");
        boolean first = true;
        for (String index : indexHints.getAllowedIndexes()) {
            if (!first) {
                buff.append(", ");
            } else {
                first = false;
            }
            buff.append(Parser.quoteIdentifier(index));
        }
        buff.append(")");
    }
    if (index != null) {
        buff.append('\n');
        StatementBuilder planBuff = new StatementBuilder();
        if (joinBatch != null) {
            IndexLookupBatch lookupBatch = joinBatch.getLookupBatch(joinFilterId);
            if (lookupBatch == null) {
                if (joinFilterId != 0) {
                    throw DbException.throwInternalError("" + joinFilterId);
                }
            } else {
                planBuff.append("batched:");
                String batchPlan = lookupBatch.getPlanSQL();
                planBuff.append(batchPlan);
                planBuff.append(" ");
            }
        }
        planBuff.append(index.getPlanSQL());
        if (!indexConditions.isEmpty()) {
            planBuff.append(": ");
            for (IndexCondition condition : indexConditions) {
                planBuff.appendExceptFirst("\n    AND ");
                planBuff.append(condition.getSQL());
            }
        }
        String plan = StringUtils.quoteRemarkSQL(planBuff.toString());
        if (plan.indexOf('\n') >= 0) {
            plan += "\n";
        }
        buff.append(StringUtils.indent("/* " + plan + " */", 4, false));
    }
    if (isJoin) {
        buff.append("\n    ON ");
        if (joinCondition == null) {
            // need to have a ON expression, otherwise the nesting is
            // unclear
            buff.append("1=1");
        } else {
            buff.append(StringUtils.unEnclose(joinCondition.getSQL()));
        }
    }
    if (filterCondition != null) {
        buff.append('\n');
        String condition = StringUtils.unEnclose(filterCondition.getSQL());
        condition = "/* WHERE " + StringUtils.quoteRemarkSQL(condition) + "\n*/";
        buff.append(StringUtils.indent(condition, 4, false));
    }
    if (scanCount > 0) {
        buff.append("\n    /* scanCount: ").append(scanCount).append(" */");
    }
    return buff.toString();
}

Example 10 with Plan

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

the class TestOptimizations method testConvertOrToIn.

private void testConvertOrToIn() throws SQLException {
    deleteDb("optimizations");
    Connection conn = getConnection("optimizations");
    Statement stat = conn.createStatement();
    stat.execute("create table test(id int primary key, name varchar(255))");
    stat.execute("insert into test values" + "(1, '1'), (2, '2'), (3, '3'), (4, '4'), (5, '5')");
    ResultSet rs = stat.executeQuery("EXPLAIN PLAN FOR SELECT * " + "FROM test WHERE ID=1 OR ID=2 OR ID=3 OR ID=4 OR ID=5");
    rs.next();
    assertContains(rs.getString(1), "ID IN(1, 2, 3, 4, 5)");
    rs = stat.executeQuery("SELECT COUNT(*) FROM test " + "WHERE ID=1 OR ID=2 OR ID=3 OR ID=4 OR ID=5");
    rs.next();
    assertEquals(5, rs.getInt(1));
    conn.close();
}