nodeRecursiveunion.h File Reference

#include "nodes/execnodes.h"

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Functions
RecursiveUnionState *	ExecInitRecursiveUnion (RecursiveUnion *node, EState *estate, int eflags)
void	ExecEndRecursiveUnion (RecursiveUnionState *node)
void	ExecReScanRecursiveUnion (RecursiveUnionState *node)

Function Documentation

ExecEndRecursiveUnion()

void ExecEndRecursiveUnion

(

RecursiveUnionState *

node

)

Definition at line 272 of file nodeRecursiveunion.c.

{
    /* Release tuplestores */
    tuplestore_end(node->working_table);
    tuplestore_end(node->intermediate_table);
 
    /* free subsidiary stuff including hashtable */
    if (node->tempContext)
        MemoryContextDelete(node->tempContext);
    if (node->tableContext)
        MemoryContextDelete(node->tableContext);
 
    /*
     * close down subplans
     */
    ExecEndNode(outerPlanState(node));
    ExecEndNode(innerPlanState(node));
}

References ExecEndNode(), innerPlanState, RecursiveUnionState::intermediate_table, MemoryContextDelete(), outerPlanState, RecursiveUnionState::tableContext, RecursiveUnionState::tempContext, tuplestore_end(), and RecursiveUnionState::working_table.

Referenced by ExecEndNode().

ExecInitRecursiveUnion()

RecursiveUnionState* ExecInitRecursiveUnion	(	RecursiveUnion *	node,
		EState *	estate,
		int	eflags
	)

Definition at line 167 of file nodeRecursiveunion.c.

{
    RecursiveUnionState *rustate;
    ParamExecData *prmdata;
 
    /* check for unsupported flags */
    Assert(!(eflags & (EXEC_FLAG_BACKWARD | EXEC_FLAG_MARK)));
 
    /*
     * create state structure
     */
    rustate = makeNode(RecursiveUnionState);
    rustate->ps.plan = (Plan *) node;
    rustate->ps.state = estate;
    rustate->ps.ExecProcNode = ExecRecursiveUnion;
 
    rustate->eqfuncoids = NULL;
    rustate->hashfunctions = NULL;
    rustate->hashtable = NULL;
    rustate->tempContext = NULL;
    rustate->tableContext = NULL;
 
    /* initialize processing state */
    rustate->recursing = false;
    rustate->intermediate_empty = true;
    rustate->working_table = tuplestore_begin_heap(false, false, work_mem);
    rustate->intermediate_table = tuplestore_begin_heap(false, false, work_mem);
 
    /*
     * If hashing, we need a per-tuple memory context for comparisons, and a
     * longer-lived context to store the hash table.  The table can't just be
     * kept in the per-query context because we want to be able to throw it
     * away when rescanning.
     */
    if (node->numCols > 0)
    {
        rustate->tempContext =
            AllocSetContextCreate(CurrentMemoryContext,
                                  "RecursiveUnion",
                                  ALLOCSET_DEFAULT_SIZES);
        rustate->tableContext =
            AllocSetContextCreate(CurrentMemoryContext,
                                  "RecursiveUnion hash table",
                                  ALLOCSET_DEFAULT_SIZES);
    }
 
    /*
     * Make the state structure available to descendant WorkTableScan nodes
     * via the Param slot reserved for it.
     */
    prmdata = &(estate->es_param_exec_vals[node->wtParam]);
    Assert(prmdata->execPlan == NULL);
    prmdata->value = PointerGetDatum(rustate);
    prmdata->isnull = false;
 
    /*
     * Miscellaneous initialization
     *
     * RecursiveUnion plans don't have expression contexts because they never
     * call ExecQual or ExecProject.
     */
    Assert(node->plan.qual == NIL);
 
    /*
     * RecursiveUnion nodes still have Result slots, which hold pointers to
     * tuples, so we have to initialize them.
     */
    ExecInitResultTypeTL(&rustate->ps);
 
    /*
     * Initialize result tuple type.  (Note: we have to set up the result type
     * before initializing child nodes, because nodeWorktablescan.c expects it
     * to be valid.)
     */
    rustate->ps.ps_ProjInfo = NULL;
 
    /*
     * initialize child nodes
     */
    outerPlanState(rustate) = ExecInitNode(outerPlan(node), estate, eflags);
    innerPlanState(rustate) = ExecInitNode(innerPlan(node), estate, eflags);
 
    /*
     * If hashing, precompute fmgr lookup data for inner loop, and create the
     * hash table.
     */
    if (node->numCols > 0)
    {
        execTuplesHashPrepare(node->numCols,
                              node->dupOperators,
                              &rustate->eqfuncoids,
                              &rustate->hashfunctions);
        build_hash_table(rustate);
    }
 
    return rustate;
}

References ALLOCSET_DEFAULT_SIZES, AllocSetContextCreate, Assert, build_hash_table(), CurrentMemoryContext, RecursiveUnionState::eqfuncoids, EState::es_param_exec_vals, EXEC_FLAG_BACKWARD, EXEC_FLAG_MARK, ExecInitNode(), ExecInitResultTypeTL(), ParamExecData::execPlan, PlanState::ExecProcNode, ExecRecursiveUnion(), execTuplesHashPrepare(), RecursiveUnionState::hashfunctions, RecursiveUnionState::hashtable, innerPlan, innerPlanState, RecursiveUnionState::intermediate_empty, RecursiveUnionState::intermediate_table, ParamExecData::isnull, makeNode, NIL, RecursiveUnion::numCols, outerPlan, outerPlanState, PlanState::plan, RecursiveUnion::plan, PointerGetDatum(), RecursiveUnionState::ps, PlanState::ps_ProjInfo, Plan::qual, RecursiveUnionState::recursing, PlanState::state, RecursiveUnionState::tableContext, RecursiveUnionState::tempContext, tuplestore_begin_heap(), ParamExecData::value, work_mem, RecursiveUnionState::working_table, and RecursiveUnion::wtParam.

Referenced by ExecInitNode().

ExecReScanRecursiveUnion()

void ExecReScanRecursiveUnion

(

RecursiveUnionState *

node

)

Definition at line 298 of file nodeRecursiveunion.c.

{
    PlanState  *outerPlan = outerPlanState(node);
    PlanState  *innerPlan = innerPlanState(node);
    RecursiveUnion *plan = (RecursiveUnion *) node->ps.plan;
 
    /*
     * Set recursive term's chgParam to tell it that we'll modify the working
     * table and therefore it has to rescan.
     */
    innerPlan->chgParam = bms_add_member(innerPlan->chgParam, plan->wtParam);
 
    /*
     * if chgParam of subnode is not null then plan will be re-scanned by
     * first ExecProcNode.  Because of above, we only have to do this to the
     * non-recursive term.
     */
    if (outerPlan->chgParam == NULL)
        ExecReScan(outerPlan);
 
    /* Release any hashtable storage */
    if (node->tableContext)
        MemoryContextReset(node->tableContext);
 
    /* Empty hashtable if needed */
    if (plan->numCols > 0)
        ResetTupleHashTable(node->hashtable);
 
    /* reset processing state */
    node->recursing = false;
    node->intermediate_empty = true;
    tuplestore_clear(node->working_table);
    tuplestore_clear(node->intermediate_table);
}

References bms_add_member(), ExecReScan(), RecursiveUnionState::hashtable, innerPlan, innerPlanState, RecursiveUnionState::intermediate_empty, RecursiveUnionState::intermediate_table, MemoryContextReset(), outerPlan, outerPlanState, PlanState::plan, plan, RecursiveUnionState::ps, RecursiveUnionState::recursing, ResetTupleHashTable(), RecursiveUnionState::tableContext, tuplestore_clear(), and RecursiveUnionState::working_table.

Referenced by ExecReScan().