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-rw-r--r--src/backend/commands/explain.c155
1 files changed, 147 insertions, 8 deletions
diff --git a/src/backend/commands/explain.c b/src/backend/commands/explain.c
index 1e8f618a347..33252a8e205 100644
--- a/src/backend/commands/explain.c
+++ b/src/backend/commands/explain.c
@@ -51,6 +51,10 @@ static void ExplainOneQuery(Query *query, IntoClause *into, ExplainState *es,
static void report_triggers(ResultRelInfo *rInfo, bool show_relname,
ExplainState *es);
static double elapsed_time(instr_time *starttime);
+static void ExplainPreScanNode(PlanState *planstate, Bitmapset **rels_used);
+static void ExplainPreScanMemberNodes(List *plans, PlanState **planstates,
+ Bitmapset **rels_used);
+static void ExplainPreScanSubPlans(List *plans, Bitmapset **rels_used);
static void ExplainNode(PlanState *planstate, List *ancestors,
const char *relationship, const char *plan_name,
ExplainState *es);
@@ -539,9 +543,13 @@ ExplainOnePlan(PlannedStmt *plannedstmt, IntoClause *into, ExplainState *es,
void
ExplainPrintPlan(ExplainState *es, QueryDesc *queryDesc)
{
+ Bitmapset *rels_used = NULL;
+
Assert(queryDesc->plannedstmt != NULL);
es->pstmt = queryDesc->plannedstmt;
es->rtable = queryDesc->plannedstmt->rtable;
+ ExplainPreScanNode(queryDesc->planstate, &rels_used);
+ es->rtable_names = select_rtable_names_for_explain(es->rtable, rels_used);
ExplainNode(queryDesc->planstate, NIL, NULL, NULL, es);
}
@@ -641,6 +649,132 @@ elapsed_time(instr_time *starttime)
}
/*
+ * ExplainPreScanNode -
+ * Prescan the planstate tree to identify which RTEs are referenced
+ *
+ * Adds the relid of each referenced RTE to *rels_used. The result controls
+ * which RTEs are assigned aliases by select_rtable_names_for_explain. This
+ * ensures that we don't confusingly assign un-suffixed aliases to RTEs that
+ * never appear in the EXPLAIN output (such as inheritance parents).
+ */
+static void
+ExplainPreScanNode(PlanState *planstate, Bitmapset **rels_used)
+{
+ Plan *plan = planstate->plan;
+
+ switch (nodeTag(plan))
+ {
+ case T_SeqScan:
+ case T_IndexScan:
+ case T_IndexOnlyScan:
+ case T_BitmapHeapScan:
+ case T_TidScan:
+ case T_SubqueryScan:
+ case T_FunctionScan:
+ case T_ValuesScan:
+ case T_CteScan:
+ case T_WorkTableScan:
+ case T_ForeignScan:
+ *rels_used = bms_add_member(*rels_used,
+ ((Scan *) plan)->scanrelid);
+ break;
+ case T_ModifyTable:
+ /* cf ExplainModifyTarget */
+ *rels_used = bms_add_member(*rels_used,
+ linitial_int(((ModifyTable *) plan)->resultRelations));
+ break;
+ default:
+ break;
+ }
+
+ /* initPlan-s */
+ if (planstate->initPlan)
+ ExplainPreScanSubPlans(planstate->initPlan, rels_used);
+
+ /* lefttree */
+ if (outerPlanState(planstate))
+ ExplainPreScanNode(outerPlanState(planstate), rels_used);
+
+ /* righttree */
+ if (innerPlanState(planstate))
+ ExplainPreScanNode(innerPlanState(planstate), rels_used);
+
+ /* special child plans */
+ switch (nodeTag(plan))
+ {
+ case T_ModifyTable:
+ ExplainPreScanMemberNodes(((ModifyTable *) plan)->plans,
+ ((ModifyTableState *) planstate)->mt_plans,
+ rels_used);
+ break;
+ case T_Append:
+ ExplainPreScanMemberNodes(((Append *) plan)->appendplans,
+ ((AppendState *) planstate)->appendplans,
+ rels_used);
+ break;
+ case T_MergeAppend:
+ ExplainPreScanMemberNodes(((MergeAppend *) plan)->mergeplans,
+ ((MergeAppendState *) planstate)->mergeplans,
+ rels_used);
+ break;
+ case T_BitmapAnd:
+ ExplainPreScanMemberNodes(((BitmapAnd *) plan)->bitmapplans,
+ ((BitmapAndState *) planstate)->bitmapplans,
+ rels_used);
+ break;
+ case T_BitmapOr:
+ ExplainPreScanMemberNodes(((BitmapOr *) plan)->bitmapplans,
+ ((BitmapOrState *) planstate)->bitmapplans,
+ rels_used);
+ break;
+ case T_SubqueryScan:
+ ExplainPreScanNode(((SubqueryScanState *) planstate)->subplan,
+ rels_used);
+ break;
+ default:
+ break;
+ }
+
+ /* subPlan-s */
+ if (planstate->subPlan)
+ ExplainPreScanSubPlans(planstate->subPlan, rels_used);
+}
+
+/*
+ * Prescan the constituent plans of a ModifyTable, Append, MergeAppend,
+ * BitmapAnd, or BitmapOr node.
+ *
+ * Note: we don't actually need to examine the Plan list members, but
+ * we need the list in order to determine the length of the PlanState array.
+ */
+static void
+ExplainPreScanMemberNodes(List *plans, PlanState **planstates,
+ Bitmapset **rels_used)
+{
+ int nplans = list_length(plans);
+ int j;
+
+ for (j = 0; j < nplans; j++)
+ ExplainPreScanNode(planstates[j], rels_used);
+}
+
+/*
+ * Prescan a list of SubPlans (or initPlans, which also use SubPlan nodes).
+ */
+static void
+ExplainPreScanSubPlans(List *plans, Bitmapset **rels_used)
+{
+ ListCell *lst;
+
+ foreach(lst, plans)
+ {
+ SubPlanState *sps = (SubPlanState *) lfirst(lst);
+
+ ExplainPreScanNode(sps->planstate, rels_used);
+ }
+}
+
+/*
* ExplainNode -
* Appends a description of a plan tree to es->str
*
@@ -1440,7 +1574,8 @@ show_plan_tlist(PlanState *planstate, List *ancestors, ExplainState *es)
/* Set up deparsing context */
context = deparse_context_for_planstate((Node *) planstate,
ancestors,
- es->rtable);
+ es->rtable,
+ es->rtable_names);
useprefix = list_length(es->rtable) > 1;
/* Deparse each result column (we now include resjunk ones) */
@@ -1471,7 +1606,8 @@ show_expression(Node *node, const char *qlabel,
/* Set up deparsing context */
context = deparse_context_for_planstate((Node *) planstate,
ancestors,
- es->rtable);
+ es->rtable,
+ es->rtable_names);
/* Deparse the expression */
exprstr = deparse_expression(node, context, useprefix, false);
@@ -1573,7 +1709,8 @@ show_sort_keys_common(PlanState *planstate, int nkeys, AttrNumber *keycols,
/* Set up deparsing context */
context = deparse_context_for_planstate((Node *) planstate,
ancestors,
- es->rtable);
+ es->rtable,
+ es->rtable_names);
useprefix = (list_length(es->rtable) > 1 || es->verbose);
for (keyno = 0; keyno < nkeys; keyno++)
@@ -1813,8 +1950,10 @@ ExplainTargetRel(Plan *plan, Index rti, ExplainState *es)
char *namespace = NULL;
const char *objecttag = NULL;
RangeTblEntry *rte;
+ char *refname;
rte = rt_fetch(rti, es->rtable);
+ refname = (char *) list_nth(es->rtable_names, rti - 1);
switch (nodeTag(plan))
{
@@ -1887,10 +2026,9 @@ ExplainTargetRel(Plan *plan, Index rti, ExplainState *es)
quote_identifier(objectname));
else if (objectname != NULL)
appendStringInfo(es->str, " %s", quote_identifier(objectname));
- if (objectname == NULL ||
- strcmp(rte->eref->aliasname, objectname) != 0)
- appendStringInfo(es->str, " %s",
- quote_identifier(rte->eref->aliasname));
+ if (refname != NULL &&
+ (objectname == NULL || strcmp(refname, objectname) != 0))
+ appendStringInfo(es->str, " %s", quote_identifier(refname));
}
else
{
@@ -1898,7 +2036,8 @@ ExplainTargetRel(Plan *plan, Index rti, ExplainState *es)
ExplainPropertyText(objecttag, objectname, es);
if (namespace != NULL)
ExplainPropertyText("Schema", namespace, es);
- ExplainPropertyText("Alias", rte->eref->aliasname, es);
+ if (refname != NULL)
+ ExplainPropertyText("Alias", refname, es);
}
}
generated by cgit v1.2.3 (git 2.25.1) at 2025-05-24 01:27:56 +0000