Examples with AggregatePlanNode org.voltdb.plannodes.AggregatePlanNode used on opensource projects

Example 6 with AggregatePlanNode

use of org.voltdb.plannodes.AggregatePlanNode in project voltdb by VoltDB.

the class TestPlansCount method testTableCount.

public void testTableCount() {
    List<AbstractPlanNode> pn = compileToFragments("SELECT count(ID) from P1");
    AbstractPlanNode p = pn.get(0).getChild(0);
    assertTrue(p instanceof AggregatePlanNode);
    p = pn.get(1).getChild(0);
    assertTrue(p instanceof TableCountPlanNode);
}

Example 7 with AggregatePlanNode

use of org.voltdb.plannodes.AggregatePlanNode in project voltdb by VoltDB.

the class PlanAssembler method addCoordinatorToDMLNode.

/**
     * Add a receive node, a sum or limit node, and a send node to the given DML node.
     * If the DML target is a replicated table, it will add a limit node,
     * otherwise it adds a sum node.
     *
     * @param dmlRoot
     * @param isReplicated Whether or not the target table is a replicated table.
     * @return
     */
private static AbstractPlanNode addCoordinatorToDMLNode(AbstractPlanNode dmlRoot, boolean isReplicated) {
    dmlRoot = SubPlanAssembler.addSendReceivePair(dmlRoot);
    AbstractPlanNode sumOrLimitNode;
    if (isReplicated) {
        // Replicated table DML result doesn't need to be summed. All partitions should
        // modify the same number of tuples in replicated table, so just pick the result from
        // any partition.
        LimitPlanNode limitNode = new LimitPlanNode();
        sumOrLimitNode = limitNode;
        limitNode.setLimit(1);
    } else {
        // create the nodes being pushed on top of dmlRoot.
        AggregatePlanNode countNode = new AggregatePlanNode();
        sumOrLimitNode = countNode;
        // configure the count aggregate (sum) node to produce a single
        // output column containing the result of the sum.
        // Create a TVE that should match the tuple count input column
        // This TVE is magic.
        // really really need to make this less hard-wired
        TupleValueExpression count_tve = new TupleValueExpression(AbstractParsedStmt.TEMP_TABLE_NAME, AbstractParsedStmt.TEMP_TABLE_NAME, "modified_tuples", "modified_tuples", 0);
        count_tve.setValueType(VoltType.BIGINT);
        count_tve.setValueSize(VoltType.BIGINT.getLengthInBytesForFixedTypes());
        countNode.addAggregate(ExpressionType.AGGREGATE_SUM, false, 0, count_tve);
        // The output column. Not really based on a TVE (it is really the
        // count expression represented by the count configured above). But
        // this is sufficient for now.  This looks identical to the above
        // TVE but it's logically different so we'll create a fresh one.
        TupleValueExpression tve = new TupleValueExpression(AbstractParsedStmt.TEMP_TABLE_NAME, AbstractParsedStmt.TEMP_TABLE_NAME, "modified_tuples", "modified_tuples", 0);
        tve.setValueType(VoltType.BIGINT);
        tve.setValueSize(VoltType.BIGINT.getLengthInBytesForFixedTypes());
        NodeSchema count_schema = new NodeSchema();
        count_schema.addColumn(AbstractParsedStmt.TEMP_TABLE_NAME, AbstractParsedStmt.TEMP_TABLE_NAME, "modified_tuples", "modified_tuples", tve);
        countNode.setOutputSchema(count_schema);
    }
    // connect the nodes to build the graph
    sumOrLimitNode.addAndLinkChild(dmlRoot);
    SendPlanNode sendNode = new SendPlanNode();
    sendNode.addAndLinkChild(sumOrLimitNode);
    return sendNode;
}

Example 8 with AggregatePlanNode

use of org.voltdb.plannodes.AggregatePlanNode in project voltdb by VoltDB.

the class PlanAssembler method handleDistinctWithGroupby.

/**
     * Handle DISTINCT with GROUP BY if it is not redundant with the
     * aggregation/grouping.
     * DISTINCT is basically rewritten with GROUP BY to benefit from
     * all kinds of GROUP BY optimizations.
     * Trivial case DISTINCT in a statement with no GROUP BY has been
     * rewritten very early at query parsing time.
     * In the non-trivial case, where an existing GROUP BY column is NOT
     * in the select list, DISTINCT can be implemented via a final aggregation
     * (never pushed down) added to the top of the plan.
     * @param root can be an aggregate plan node or projection plan node
     * @return
     */
private AbstractPlanNode handleDistinctWithGroupby(AbstractPlanNode root) {
    if (!m_parsedSelect.hasDistinctWithGroupBy()) {
        return root;
    }
    assert (m_parsedSelect.isGrouped());
    // all of the grouping columns are present in the display columns.
    if (m_parsedSelect.displayColumnsContainAllGroupByColumns()) {
        return root;
    }
    // Now non complex aggregation cases are handled already
    assert (m_parsedSelect.hasComplexAgg());
    AggregatePlanNode distinctAggNode = new HashAggregatePlanNode();
    distinctAggNode.setOutputSchema(m_parsedSelect.getDistinctProjectionSchema());
    for (ParsedColInfo col : m_parsedSelect.distinctGroupByColumns()) {
        distinctAggNode.addGroupByExpression(col.expression);
    }
    // TODO(xin): push down the DISTINCT for certain cases
    // Ticket: ENG-7360
    /*
        boolean pushedDown = false;
        boolean canPushdownDistinctAgg =
                m_parsedSelect.hasPartitionColumnInDistinctGroupby();
        //
        // disable pushdown, DISTINCT push down turns out complex
        //
        canPushdownDistinctAgg = false;

        if (canPushdownDistinctAgg && !m_parsedSelect.m_mvFixInfo.needed()) {
            assert(m_parsedSelect.hasPartitionColumnInGroupby());
            AbstractPlanNode receive = root;

            if (receive instanceof ReceivePlanNode) {
                // Temporarily strip send/receive pair
                AbstractPlanNode distNode = receive.getChild(0).getChild(0);
                receive.getChild(0).unlinkChild(distNode);

                distinctAggNode.addAndLinkChild(distNode);
                receive.getChild(0).addAndLinkChild(distinctAggNode);

                pushedDown = true;
            }
        }*/
    distinctAggNode.addAndLinkChild(root);
    root = distinctAggNode;
    return root;
}

Example 9 with AggregatePlanNode

use of org.voltdb.plannodes.AggregatePlanNode in project voltdb by VoltDB.

the class PlanAssembler method handleAggregationOperators.

private AbstractPlanNode handleAggregationOperators(AbstractPlanNode root) {
    /*
         * "Select A from T group by A" is grouped but has no aggregate operator
         * expressions. Catch that case by checking the grouped flag
         */
    if (m_parsedSelect.hasAggregateOrGroupby()) {
        AggregatePlanNode aggNode = null;
        // i.e., on the coordinator
        AggregatePlanNode topAggNode = null;
        IndexGroupByInfo gbInfo = new IndexGroupByInfo();
        if (root instanceof AbstractReceivePlanNode) {
            // for distinct that does not group by partition column
            if (!m_parsedSelect.hasAggregateDistinct() || m_parsedSelect.hasPartitionColumnInGroupby()) {
                AbstractPlanNode candidate = root.getChild(0).getChild(0);
                gbInfo.m_multiPartition = true;
                switchToIndexScanForGroupBy(candidate, gbInfo);
            }
        } else if (switchToIndexScanForGroupBy(root, gbInfo)) {
            root = gbInfo.m_indexAccess;
        }
        boolean needHashAgg = gbInfo.needHashAggregator(root, m_parsedSelect);
        // Construct the aggregate nodes
        if (needHashAgg) {
            if (m_parsedSelect.m_mvFixInfo.needed()) {
                // TODO: may optimize this edge case in future
                aggNode = new HashAggregatePlanNode();
            } else {
                if (gbInfo.isChangedToSerialAggregate()) {
                    assert (root instanceof ReceivePlanNode);
                    aggNode = new AggregatePlanNode();
                } else if (gbInfo.isChangedToPartialAggregate()) {
                    aggNode = new PartialAggregatePlanNode(gbInfo.m_coveredGroupByColumns);
                } else {
                    aggNode = new HashAggregatePlanNode();
                }
                topAggNode = new HashAggregatePlanNode();
            }
        } else {
            aggNode = new AggregatePlanNode();
            if (!m_parsedSelect.m_mvFixInfo.needed()) {
                topAggNode = new AggregatePlanNode();
            }
        }
        NodeSchema agg_schema = new NodeSchema();
        NodeSchema top_agg_schema = new NodeSchema();
        for (int outputColumnIndex = 0; outputColumnIndex < m_parsedSelect.m_aggResultColumns.size(); outputColumnIndex += 1) {
            ParsedColInfo col = m_parsedSelect.m_aggResultColumns.get(outputColumnIndex);
            AbstractExpression rootExpr = col.expression;
            AbstractExpression agg_input_expr = null;
            SchemaColumn schema_col = null;
            SchemaColumn top_schema_col = null;
            if (rootExpr instanceof AggregateExpression) {
                ExpressionType agg_expression_type = rootExpr.getExpressionType();
                agg_input_expr = rootExpr.getLeft();
                // A bit of a hack: ProjectionNodes after the
                // aggregate node need the output columns here to
                // contain TupleValueExpressions (effectively on a temp table).
                // So we construct one based on the output of the
                // aggregate expression, the column alias provided by HSQL,
                // and the offset into the output table schema for the
                // aggregate node that we're computing.
                // Oh, oh, it's magic, you know..
                TupleValueExpression tve = new TupleValueExpression(AbstractParsedStmt.TEMP_TABLE_NAME, AbstractParsedStmt.TEMP_TABLE_NAME, "", col.alias, rootExpr, outputColumnIndex);
                tve.setDifferentiator(col.differentiator);
                boolean is_distinct = ((AggregateExpression) rootExpr).isDistinct();
                aggNode.addAggregate(agg_expression_type, is_distinct, outputColumnIndex, agg_input_expr);
                schema_col = new SchemaColumn(AbstractParsedStmt.TEMP_TABLE_NAME, AbstractParsedStmt.TEMP_TABLE_NAME, "", col.alias, tve, outputColumnIndex);
                top_schema_col = new SchemaColumn(AbstractParsedStmt.TEMP_TABLE_NAME, AbstractParsedStmt.TEMP_TABLE_NAME, "", col.alias, tve, outputColumnIndex);
                /*
                     * Special case count(*), count(), sum(), min() and max() to
                     * push them down to each partition. It will do the
                     * push-down if the select columns only contains the listed
                     * aggregate operators and other group-by columns. If the
                     * select columns includes any other aggregates, it will not
                     * do the push-down. - nshi
                     */
                if (topAggNode != null) {
                    ExpressionType top_expression_type = agg_expression_type;
                    /*
                         * For count(*), count() and sum(), the pushed-down
                         * aggregate node doesn't change. An extra sum()
                         * aggregate node is added to the coordinator to sum up
                         * the numbers from all the partitions. The input schema
                         * and the output schema of the sum() aggregate node is
                         * the same as the output schema of the push-down
                         * aggregate node.
                         *
                         * If DISTINCT is specified, don't do push-down for
                         * count() and sum() when not group by partition column.
                         * An exception is the aggregation arguments are the
                         * partition column (ENG-4980).
                         */
                    if (agg_expression_type == ExpressionType.AGGREGATE_COUNT_STAR || agg_expression_type == ExpressionType.AGGREGATE_COUNT || agg_expression_type == ExpressionType.AGGREGATE_SUM) {
                        if (is_distinct && !(m_parsedSelect.hasPartitionColumnInGroupby() || canPushDownDistinctAggregation((AggregateExpression) rootExpr))) {
                            topAggNode = null;
                        } else {
                            // for aggregate distinct when group by
                            // partition column, the top aggregate node
                            // will be dropped later, thus there is no
                            // effect to assign the top_expression_type.
                            top_expression_type = ExpressionType.AGGREGATE_SUM;
                        }
                    } else /*
                         * For min() and max(), the pushed-down aggregate node
                         * doesn't change. An extra aggregate node of the same
                         * type is added to the coordinator. The input schema
                         * and the output schema of the top aggregate node is
                         * the same as the output schema of the pushed-down
                         * aggregate node.
                         *
                         * APPROX_COUNT_DISTINCT can be similarly pushed down, but
                         * must be split into two different functions, which is
                         * done later, from pushDownAggregate().
                         */
                    if (agg_expression_type != ExpressionType.AGGREGATE_MIN && agg_expression_type != ExpressionType.AGGREGATE_MAX && agg_expression_type != ExpressionType.AGGREGATE_APPROX_COUNT_DISTINCT) {
                        /*
                             * Unsupported aggregate for push-down (AVG for example).
                             */
                        topAggNode = null;
                    }
                    if (topAggNode != null) {
                        /*
                             * Input column of the top aggregate node is the
                             * output column of the push-down aggregate node
                             */
                        boolean topDistinctFalse = false;
                        topAggNode.addAggregate(top_expression_type, topDistinctFalse, outputColumnIndex, tve);
                    }
                }
            // end if we have a top agg node
            } else {
                // has already been broken down.
                assert (!rootExpr.hasAnySubexpressionOfClass(AggregateExpression.class));
                /*
                     * These columns are the pass through columns that are not being
                     * aggregated on. These are the ones from the SELECT list. They
                     * MUST already exist in the child node's output. Find them and
                     * add them to the aggregate's output.
                     */
                schema_col = new SchemaColumn(col.tableName, col.tableAlias, col.columnName, col.alias, col.expression, outputColumnIndex);
                AbstractExpression topExpr = null;
                if (col.groupBy) {
                    topExpr = m_parsedSelect.m_groupByExpressions.get(col.alias);
                } else {
                    topExpr = col.expression;
                }
                top_schema_col = new SchemaColumn(col.tableName, col.tableAlias, col.columnName, col.alias, topExpr, outputColumnIndex);
            }
            agg_schema.addColumn(schema_col);
            top_agg_schema.addColumn(top_schema_col);
        }
        for (ParsedColInfo col : m_parsedSelect.groupByColumns()) {
            aggNode.addGroupByExpression(col.expression);
            if (topAggNode != null) {
                topAggNode.addGroupByExpression(m_parsedSelect.m_groupByExpressions.get(col.alias));
            }
        }
        aggNode.setOutputSchema(agg_schema);
        if (topAggNode != null) {
            if (m_parsedSelect.hasComplexGroupby()) {
                topAggNode.setOutputSchema(top_agg_schema);
            } else {
                topAggNode.setOutputSchema(agg_schema);
            }
        }
        // Never push down aggregation for MV fix case.
        root = pushDownAggregate(root, aggNode, topAggNode, m_parsedSelect);
    }
    return handleDistinctWithGroupby(root);
}

Example 10 with AggregatePlanNode

use of org.voltdb.plannodes.AggregatePlanNode in project voltdb by VoltDB.

the class PlanAssembler method isValidAggregateNodeForLimitPushdown.

private static boolean isValidAggregateNodeForLimitPushdown(AbstractPlanNode aggregateNode, List<ParsedColInfo> orderBys, boolean orderByCoversAllGroupBy) {
    if (aggregateNode instanceof AggregatePlanNode == false) {
        return false;
    }
    if (aggregateNode.getParentCount() == 0) {
        return false;
    }
    // Limitation: can only push past coordinating aggregation nodes
    if (!((AggregatePlanNode) aggregateNode).m_isCoordinatingAggregator) {
        return false;
    }
    AbstractPlanNode parent = aggregateNode.getParent(0);
    AbstractPlanNode orderByNode = null;
    if (parent instanceof OrderByPlanNode) {
        orderByNode = parent;
    } else if (parent instanceof ProjectionPlanNode && parent.getParentCount() > 0 && parent.getParent(0) instanceof OrderByPlanNode) {
        // Xin really wants inline project with aggregation
        orderByNode = parent.getParent(0);
    }
    if (orderByNode == null) {
        // the limit should not be pushed down.
        return false;
    }
    if ((!orderByCoversAllGroupBy) || isOrderByAggregationValue(orderBys)) {
        return false;
    }
    return true;
}