/*
* recurse_set_operations
* Recursively handle one step in a tree of set operations
*
* colTypes: list of type OIDs of expected output columns
* junkOK: if true, child resjunk columns may be left in the result
* flag: if >= 0, add a resjunk output column indicating value of flag
* refnames_tlist: targetlist to take column names from
*/
static Plan *
recurse_set_operations(Node *setOp, Query *parse,
List *colTypes, bool junkOK,
int flag, List *refnames_tlist)
{
if (IsA(setOp, RangeTblRef))
{
RangeTblRef *rtr = (RangeTblRef *) setOp;
RangeTblEntry *rte = rt_fetch(rtr->rtindex, parse->rtable);
Query *subquery = rte->subquery;
Plan *subplan,
*plan;
Assert(subquery != NULL);
/*
* Generate plan for primitive subquery
*/
subplan = subquery_planner(subquery, 0.0 /* default case */ );
/*
* Add a SubqueryScan with the caller-requested targetlist
*/
plan = (Plan *)
make_subqueryscan(generate_setop_tlist(colTypes, flag, true,
subplan->targetlist,
refnames_tlist),
NIL,
rtr->rtindex,
subplan);
return plan;
}
else if (IsA(setOp, SetOperationStmt))
{
SetOperationStmt *op = (SetOperationStmt *) setOp;
Plan *plan;
/* UNIONs are much different from INTERSECT/EXCEPT */
if (op->op == SETOP_UNION)
plan = generate_union_plan(op, parse, refnames_tlist);
else
plan = generate_nonunion_plan(op, parse, refnames_tlist);
/*
* If necessary, add a Result node to project the caller-requested
* output columns.
*
* XXX you don't really want to know about this: setrefs.c will apply
* replace_vars_with_subplan_refs() to the Result node's tlist.
* This would fail if the Vars generated by generate_setop_tlist()
* were not exactly equal() to the corresponding tlist entries of
* the subplan. However, since the subplan was generated by
* generate_union_plan() or generate_nonunion_plan(), and hence
* its tlist was generated by generate_append_tlist(), this will
* work.
*/
if (flag >= 0 ||
!tlist_same_datatypes(plan->targetlist, colTypes, junkOK))
{
plan = (Plan *)
make_result(generate_setop_tlist(colTypes, flag, false,
plan->targetlist,
refnames_tlist),
NULL,
plan);
}
return plan;
}
else
{
elog(ERROR, "unrecognized node type: %d",
(int) nodeTag(setOp));
return NULL; /* keep compiler quiet */
}
}
/*
* recurse_set_operations
* Recursively handle one step in a tree of set operations
*
* tuple_fraction: fraction of tuples we expect to retrieve from node
* colTypes: list of type OIDs of expected output columns
* junkOK: if true, child resjunk columns may be left in the result
* flag: if >= 0, add a resjunk output column indicating value of flag
* refnames_tlist: targetlist to take column names from
* *sortClauses: receives list of SortClauses for result plan, if any
*
* We don't have to care about typmods here: the only allowed difference
* between set-op input and output typmods is input is a specific typmod
* and output is -1, and that does not require a coercion.
*/
static Plan *
recurse_set_operations(Node *setOp, PlannerInfo *root,
double tuple_fraction,
List *colTypes, bool junkOK,
int flag, List *refnames_tlist,
List **sortClauses)
{
if (IsA(setOp, RangeTblRef))
{
RangeTblRef *rtr = (RangeTblRef *) setOp;
RangeTblEntry *rte = rt_fetch(rtr->rtindex, root->parse->rtable);
Query *subquery = rte->subquery;
Plan *subplan,
*plan;
Assert(subquery != NULL);
/*
* Generate plan for primitive subquery
*/
subplan = subquery_planner(subquery, tuple_fraction, NULL);
/*
* Add a SubqueryScan with the caller-requested targetlist
*/
plan = (Plan *)
make_subqueryscan(generate_setop_tlist(colTypes, flag,
rtr->rtindex,
true,
subplan->targetlist,
refnames_tlist),
NIL,
rtr->rtindex,
subplan);
/*
* We don't bother to determine the subquery's output ordering since
* it won't be reflected in the set-op result anyhow.
*/
*sortClauses = NIL;
return plan;
}
else if (IsA(setOp, SetOperationStmt))
{
SetOperationStmt *op = (SetOperationStmt *) setOp;
Plan *plan;
/* UNIONs are much different from INTERSECT/EXCEPT */
if (op->op == SETOP_UNION)
plan = generate_union_plan(op, root, tuple_fraction,
refnames_tlist,
sortClauses);
else
plan = generate_nonunion_plan(op, root,
refnames_tlist,
sortClauses);
/*
* If necessary, add a Result node to project the caller-requested
* output columns.
*
* XXX you don't really want to know about this: setrefs.c will apply
* replace_vars_with_subplan_refs() to the Result node's tlist. This
* would fail if the Vars generated by generate_setop_tlist() were not
* exactly equal() to the corresponding tlist entries of the subplan.
* However, since the subplan was generated by generate_union_plan()
* or generate_nonunion_plan(), and hence its tlist was generated by
* generate_append_tlist(), this will work. We just tell
* generate_setop_tlist() to use varno 0.
*/
if (flag >= 0 ||
!tlist_same_datatypes(plan->targetlist, colTypes, junkOK))
{
plan = (Plan *)
make_result(generate_setop_tlist(colTypes, flag,
0,
false,
plan->targetlist,
refnames_tlist),
NULL,
plan);
}
return plan;
}
else
{
elog(ERROR, "unrecognized node type: %d",
(int) nodeTag(setOp));
return NULL; /* keep compiler quiet */
}
}
