/* ----------------------------------------------------------------
* ExecInitGather
* ----------------------------------------------------------------
*/
GatherMergeState *
ExecInitGatherMerge(GatherMerge *node, EState *estate, int eflags)
{
GatherMergeState *gm_state;
Plan *outerNode;
TupleDesc tupDesc;
/* Gather merge node doesn't have innerPlan node. */
Assert(innerPlan(node) == NULL);
/*
* create state structure
*/
gm_state = makeNode(GatherMergeState);
gm_state->ps.plan = (Plan *) node;
gm_state->ps.state = estate;
gm_state->ps.ExecProcNode = ExecGatherMerge;
gm_state->initialized = false;
gm_state->gm_initialized = false;
gm_state->tuples_needed = -1;
/*
* Miscellaneous initialization
*
* create expression context for node
*/
ExecAssignExprContext(estate, &gm_state->ps);
/*
* GatherMerge doesn't support checking a qual (it's always more efficient
* to do it in the child node).
*/
Assert(!node->plan.qual);
/*
* now initialize outer plan
*/
outerNode = outerPlan(node);
outerPlanState(gm_state) = ExecInitNode(outerNode, estate, eflags);
/*
* Leader may access ExecProcNode result directly (if
* need_to_scan_locally), or from workers via tuple queue. So we can't
* trivially rely on the slot type being fixed for expressions evaluated
* within this node.
*/
gm_state->ps.outeropsset = true;
gm_state->ps.outeropsfixed = false;
/*
* Store the tuple descriptor into gather merge state, so we can use it
* while initializing the gather merge slots.
*/
tupDesc = ExecGetResultType(outerPlanState(gm_state));
gm_state->tupDesc = tupDesc;
/*
* Initialize result type and projection.
*/
ExecInitResultTypeTL(&gm_state->ps);
ExecConditionalAssignProjectionInfo(&gm_state->ps, tupDesc, OUTER_VAR);
/*
* Without projections result slot type is not trivially known, see
* comment above.
*/
if (gm_state->ps.ps_ProjInfo == NULL)
{
gm_state->ps.resultopsset = true;
gm_state->ps.resultopsfixed = false;
}
/*
* initialize sort-key information
*/
if (node->numCols)
{
int i;
gm_state->gm_nkeys = node->numCols;
gm_state->gm_sortkeys =
palloc0(sizeof(SortSupportData) * node->numCols);
for (i = 0; i < node->numCols; i++)
{
SortSupport sortKey = gm_state->gm_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];
/*
* We don't perform abbreviated key conversion here, for the same
* reasons that it isn't used in MergeAppend
*/
sortKey->abbreviate = false;
PrepareSortSupportFromOrderingOp(node->sortOperators[i], sortKey);
}
}
/* Now allocate the workspace for gather merge */
gather_merge_setup(gm_state);
return gm_state;
}
/* ----------------------------------------------------------------
* ExecInitGather
* ----------------------------------------------------------------
*/
GatherMergeState *
ExecInitGatherMerge(GatherMerge *node, EState *estate, int eflags)
{
GatherMergeState *gm_state;
Plan *outerNode;
bool hasoid;
TupleDesc tupDesc;
/* Gather merge node doesn't have innerPlan node. */
Assert(innerPlan(node) == NULL);
/*
* create state structure
*/
gm_state = makeNode(GatherMergeState);
gm_state->ps.plan = (Plan *) node;
gm_state->ps.state = estate;
gm_state->ps.ExecProcNode = ExecGatherMerge;
/*
* Miscellaneous initialization
*
* create expression context for node
*/
ExecAssignExprContext(estate, &gm_state->ps);
/*
* initialize child expressions
*/
gm_state->ps.qual =
ExecInitQual(node->plan.qual, &gm_state->ps);
/*
* tuple table initialization
*/
ExecInitResultTupleSlot(estate, &gm_state->ps);
/*
* now initialize outer plan
*/
outerNode = outerPlan(node);
outerPlanState(gm_state) = ExecInitNode(outerNode, estate, eflags);
/*
* Initialize result tuple type and projection info.
*/
ExecAssignResultTypeFromTL(&gm_state->ps);
ExecAssignProjectionInfo(&gm_state->ps, NULL);
gm_state->gm_initialized = false;
/*
* initialize sort-key information
*/
if (node->numCols)
{
int i;
gm_state->gm_nkeys = node->numCols;
gm_state->gm_sortkeys =
palloc0(sizeof(SortSupportData) * node->numCols);
for (i = 0; i < node->numCols; i++)
{
SortSupport sortKey = gm_state->gm_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];
/*
* We don't perform abbreviated key conversion here, for the same
* reasons that it isn't used in MergeAppend
*/
sortKey->abbreviate = false;
PrepareSortSupportFromOrderingOp(node->sortOperators[i], sortKey);
}
}
/*
* store the tuple descriptor into gather merge state, so we can use it
* later while initializing the gather merge slots.
*/
if (!ExecContextForcesOids(&gm_state->ps, &hasoid))
hasoid = false;
tupDesc = ExecTypeFromTL(outerNode->targetlist, hasoid);
gm_state->tupDesc = tupDesc;
return gm_state;
}