Examples with ParsedUnionStmt org.voltdb.planner.ParsedUnionStmt used on opensource projects

Example 1 with ParsedUnionStmt

use of org.voltdb.planner.ParsedUnionStmt in project voltdb by VoltDB.

the class StmtSubqueryScan method canRunInOneFragment.

/**
     * Some subquery results can only be joined with a partitioned table after
     * it finishes some work on the coordinator. With the 2 fragment plan limit,
     * those queries can not be supported.
     * Other than that case, the planner will typically have added a
     * send/receive pair to the subquery plan that is actually only suitable to
     * a stand-alone plan. This function distinguishes subqueries that should NOT
     * have a send/receive pair.
     * @param root
     * @return true if there is no aspect to the plan that requires execution on the coordinator.
     */
public boolean canRunInOneFragment() {
    assert (m_subqueriesPartitioning != null);
    assert (m_subqueryStmt != null);
    if (m_subqueriesPartitioning.getCountOfPartitionedTables() == 0) {
        return true;
    }
    // of their results.
    if (failsSingleFragmentTest()) {
        return false;
    }
    // Tentative assignment in case of early return.
    // This gets immediately reset if it passes all the tests.
    m_failedSingleFragmentTest = true;
    if (m_subqueryStmt instanceof ParsedUnionStmt) {
        // Union are just returned
        return false;
    }
    if (!(m_subqueryStmt instanceof ParsedSelectStmt)) {
        throw new PlanningErrorException("Unsupported subquery found in FROM clause:" + m_subqueryStmt);
    }
    ParsedSelectStmt selectStmt = (ParsedSelectStmt) m_subqueryStmt;
    // we should get rid of the receive node. I (--paul) don't know what this means.
    if (selectStmt.hasLimitOrOffset() || selectStmt.hasDistinctWithGroupBy()) {
        return false;
    }
    // because it contains a partitioned view that does not have a partition column.
    if (selectStmt.m_mvFixInfo.needed()) {
        return false;
    }
    // Table aggregate cases should not get rid of the receive node
    if (selectStmt.hasAggregateOrGroupby()) {
        if (!selectStmt.isGrouped()) {
            m_tableAggregateSubquery = true;
            return false;
        }
        // Detect case (1) to mark receive node.
        if (!selectStmt.hasPartitionColumnInGroupby()) {
            return false;
        }
    }
    if (!selectStmt.hasPartitionColumnInWindowFunctionExpression()) {
        return false;
    }
    // Now. If this sub-query joins with a partitioned table in the parent statement,
    // push the join down by removing the send/receive plan node pair.
    m_failedSingleFragmentTest = false;
    return true;
}