nodeMergeAppend.h File Reference

#include "nodes/execnodes.h"

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Functions
MergeAppendState *	ExecInitMergeAppend (MergeAppend *node, EState *estate, int eflags)
void	ExecEndMergeAppend (MergeAppendState *node)
void	ExecReScanMergeAppend (MergeAppendState *node)

Function Documentation

ExecEndMergeAppend()

void ExecEndMergeAppend

(

MergeAppendState *

node

)

Definition at line 335 of file nodeMergeAppend.c.

{
    PlanState **mergeplans;
    int         nplans;
    int         i;
 
    /*
     * get information from the node
     */
    mergeplans = node->mergeplans;
    nplans = node->ms_nplans;
 
    /*
     * shut down each of the subscans
     */
    for (i = 0; i < nplans; i++)
        ExecEndNode(mergeplans[i]);
}

References ExecEndNode(), i, MergeAppendState::mergeplans, and MergeAppendState::ms_nplans.

Referenced by ExecEndNode().

ExecInitMergeAppend()

MergeAppendState * ExecInitMergeAppend	(	MergeAppend *	node,
		EState *	estate,
		int	eflags
	)

Definition at line 65 of file nodeMergeAppend.c.

{
    MergeAppendState *mergestate = makeNode(MergeAppendState);
    PlanState **mergeplanstates;
    const TupleTableSlotOps *mergeops;
    Bitmapset  *validsubplans;
    int         nplans;
    int         i,
                j;
 
    /* check for unsupported flags */
    Assert(!(eflags & (EXEC_FLAG_BACKWARD | EXEC_FLAG_MARK)));
 
    /*
     * create new MergeAppendState for our node
     */
    mergestate->ps.plan = (Plan *) node;
    mergestate->ps.state = estate;
    mergestate->ps.ExecProcNode = ExecMergeAppend;
 
    /* If run-time partition pruning is enabled, then set that up now */
    if (node->part_prune_index >= 0)
    {
        PartitionPruneState *prunestate;
 
        /*
         * Set up pruning data structure.  This also initializes the set of
         * subplans to initialize (validsubplans) by taking into account the
         * result of performing initial pruning if any.
         */
        prunestate = ExecInitPartitionExecPruning(&mergestate->ps,
                                                  list_length(node->mergeplans),
                                                  node->part_prune_index,
                                                  node->apprelids,
                                                  &validsubplans);
        mergestate->ms_prune_state = prunestate;
        nplans = bms_num_members(validsubplans);
 
        /*
         * When no run-time pruning is required and there's at least one
         * subplan, we can fill ms_valid_subplans immediately, preventing
         * later calls to ExecFindMatchingSubPlans.
         */
        if (!prunestate->do_exec_prune && nplans > 0)
            mergestate->ms_valid_subplans = bms_add_range(NULL, 0, nplans - 1);
    }
    else
    {
        nplans = list_length(node->mergeplans);
 
        /*
         * When run-time partition pruning is not enabled we can just mark all
         * subplans as valid; they must also all be initialized.
         */
        Assert(nplans > 0);
        mergestate->ms_valid_subplans = validsubplans =
            bms_add_range(NULL, 0, nplans - 1);
        mergestate->ms_prune_state = NULL;
    }
 
    mergeplanstates = (PlanState **) palloc(nplans * sizeof(PlanState *));
    mergestate->mergeplans = mergeplanstates;
    mergestate->ms_nplans = nplans;
 
    mergestate->ms_slots = (TupleTableSlot **) palloc0(sizeof(TupleTableSlot *) * nplans);
    mergestate->ms_heap = binaryheap_allocate(nplans, heap_compare_slots,
                                              mergestate);
 
    /*
     * call ExecInitNode on each of the valid plans to be executed and save
     * the results into the mergeplanstates array.
     */
    j = 0;
    i = -1;
    while ((i = bms_next_member(validsubplans, i)) >= 0)
    {
        Plan       *initNode = (Plan *) list_nth(node->mergeplans, i);
 
        mergeplanstates[j++] = ExecInitNode(initNode, estate, eflags);
    }
 
    /*
     * Initialize MergeAppend's result tuple type and slot.  If the child
     * plans all produce the same fixed slot type, we can use that slot type;
     * otherwise make a virtual slot.  (Note that the result slot itself is
     * used only to return a null tuple at end of execution; real tuples are
     * returned to the caller in the children's own result slots.  What we are
     * doing here is allowing the parent plan node to optimize if the
     * MergeAppend will return only one kind of slot.)
     */
    mergeops = ExecGetCommonSlotOps(mergeplanstates, j);
    if (mergeops != NULL)
    {
        ExecInitResultTupleSlotTL(&mergestate->ps, mergeops);
    }
    else
    {
        ExecInitResultTupleSlotTL(&mergestate->ps, &TTSOpsVirtual);
        /* show that the output slot type is not fixed */
        mergestate->ps.resultopsset = true;
        mergestate->ps.resultopsfixed = false;
    }
 
    /*
     * Miscellaneous initialization
     */
    mergestate->ps.ps_ProjInfo = NULL;
 
    /*
     * initialize sort-key information
     */
    mergestate->ms_nkeys = node->numCols;
    mergestate->ms_sortkeys = palloc0(sizeof(SortSupportData) * node->numCols);
 
    for (i = 0; i < node->numCols; i++)
    {
        SortSupport sortKey = mergestate->ms_sortkeys + i;
 
        sortKey->ssup_cxt = CurrentMemoryContext;
        sortKey->ssup_collation = node->collations[i];
        sortKey->ssup_nulls_first = node->nullsFirst[i];
        sortKey->ssup_attno = node->sortColIdx[i];
 
        /*
         * It isn't feasible to perform abbreviated key conversion, since
         * tuples are pulled into mergestate's binary heap as needed.  It
         * would likely be counter-productive to convert tuples into an
         * abbreviated representation as they're pulled up, so opt out of that
         * additional optimization entirely.
         */
        sortKey->abbreviate = false;
 
        PrepareSortSupportFromOrderingOp(node->sortOperators[i], sortKey);
    }
 
    /*
     * initialize to show we have not run the subplans yet
     */
    mergestate->ms_initialized = false;
 
    return mergestate;
}

References SortSupportData::abbreviate, MergeAppend::apprelids, Assert(), binaryheap_allocate(), bms_add_range(), bms_next_member(), bms_num_members(), CurrentMemoryContext, PartitionPruneState::do_exec_prune, EXEC_FLAG_BACKWARD, EXEC_FLAG_MARK, ExecGetCommonSlotOps(), ExecInitNode(), ExecInitPartitionExecPruning(), ExecInitResultTupleSlotTL(), ExecMergeAppend(), PlanState::ExecProcNode, heap_compare_slots(), i, j, list_length(), list_nth(), makeNode, MergeAppendState::mergeplans, MergeAppend::mergeplans, MergeAppendState::ms_heap, MergeAppendState::ms_initialized, MergeAppendState::ms_nkeys, MergeAppendState::ms_nplans, MergeAppendState::ms_prune_state, MergeAppendState::ms_slots, MergeAppendState::ms_sortkeys, MergeAppendState::ms_valid_subplans, MergeAppend::numCols, palloc(), palloc0(), MergeAppend::part_prune_index, PlanState::plan, PrepareSortSupportFromOrderingOp(), MergeAppendState::ps, PlanState::ps_ProjInfo, PlanState::resultopsfixed, PlanState::resultopsset, SortSupportData::ssup_attno, SortSupportData::ssup_collation, SortSupportData::ssup_cxt, SortSupportData::ssup_nulls_first, PlanState::state, and TTSOpsVirtual.

Referenced by ExecInitNode().

ExecReScanMergeAppend()

void ExecReScanMergeAppend

(

MergeAppendState *

node

)

Definition at line 355 of file nodeMergeAppend.c.

{
    int         i;
 
    /*
     * If any PARAM_EXEC Params used in pruning expressions have changed, then
     * we'd better unset the valid subplans so that they are reselected for
     * the new parameter values.
     */
    if (node->ms_prune_state &&
        bms_overlap(node->ps.chgParam,
                    node->ms_prune_state->execparamids))
    {
        bms_free(node->ms_valid_subplans);
        node->ms_valid_subplans = NULL;
    }
 
    for (i = 0; i < node->ms_nplans; i++)
    {
        PlanState  *subnode = node->mergeplans[i];
 
        /*
         * ExecReScan doesn't know about my subplans, so I have to do
         * changed-parameter signaling myself.
         */
        if (node->ps.chgParam != NULL)
            UpdateChangedParamSet(subnode, node->ps.chgParam);
 
        /*
         * If chgParam of subnode is not null then plan will be re-scanned by
         * first ExecProcNode.
         */
        if (subnode->chgParam == NULL)
            ExecReScan(subnode);
    }
    binaryheap_reset(node->ms_heap);
    node->ms_initialized = false;
}

References binaryheap_reset(), bms_free(), bms_overlap(), PlanState::chgParam, PartitionPruneState::execparamids, ExecReScan(), i, MergeAppendState::mergeplans, MergeAppendState::ms_heap, MergeAppendState::ms_initialized, MergeAppendState::ms_nplans, MergeAppendState::ms_prune_state, MergeAppendState::ms_valid_subplans, MergeAppendState::ps, and UpdateChangedParamSet().

Referenced by ExecReScan().