diff --git a/src/backend/commands/explain.c b/src/backend/commands/explain.c index 799a22e9d5..031ab54180 100644 --- a/src/backend/commands/explain.c +++ b/src/backend/commands/explain.c @@ -118,8 +118,9 @@ static void ExplainModifyTarget(ModifyTable *plan, ExplainState *es); static void ExplainTargetRel(Plan *plan, Index rti, ExplainState *es); static void show_modifytable_info(ModifyTableState *mtstate, List *ancestors, ExplainState *es); -static void ExplainMemberNodes(PlanState **planstates, int nsubnodes, - int nplans, List *ancestors, ExplainState *es); +static void ExplainMemberNodes(PlanState **planstates, int nplans, + List *ancestors, ExplainState *es); +static void ExplainMissingMembers(int nplans, int nchildren, ExplainState *es); static void ExplainSubPlans(List *plans, List *ancestors, const char *relationship, ExplainState *es); static void ExplainCustomChildren(CustomScanState *css, @@ -1862,6 +1863,30 @@ ExplainNode(PlanState *planstate, List *ancestors, ExplainCloseGroup("Workers", "Workers", false, es); } + /* + * If partition pruning was done during executor initialization, the + * number of child plans we'll display below will be less than the number + * of subplans that was specified in the plan. To make this a bit less + * mysterious, emit an indication that this happened. Note that this + * field is emitted now because we want it to be a property of the parent + * node; it *cannot* be emitted within the Plans sub-node we'll open next. + */ + switch (nodeTag(plan)) + { + case T_Append: + ExplainMissingMembers(((AppendState *) planstate)->as_nplans, + list_length(((Append *) plan)->appendplans), + es); + break; + case T_MergeAppend: + ExplainMissingMembers(((MergeAppendState *) planstate)->ms_nplans, + list_length(((MergeAppend *) plan)->mergeplans), + es); + break; + default: + break; + } + /* Get ready to display the child plans */ haschildren = planstate->initPlan || outerPlanState(planstate) || @@ -1902,31 +1927,26 @@ ExplainNode(PlanState *planstate, List *ancestors, case T_ModifyTable: ExplainMemberNodes(((ModifyTableState *) planstate)->mt_plans, ((ModifyTableState *) planstate)->mt_nplans, - list_length(((ModifyTable *) plan)->plans), ancestors, es); break; case T_Append: ExplainMemberNodes(((AppendState *) planstate)->appendplans, ((AppendState *) planstate)->as_nplans, - list_length(((Append *) plan)->appendplans), ancestors, es); break; case T_MergeAppend: ExplainMemberNodes(((MergeAppendState *) planstate)->mergeplans, ((MergeAppendState *) planstate)->ms_nplans, - list_length(((MergeAppend *) plan)->mergeplans), ancestors, es); break; case T_BitmapAnd: ExplainMemberNodes(((BitmapAndState *) planstate)->bitmapplans, ((BitmapAndState *) planstate)->nplans, - list_length(((BitmapAnd *) plan)->bitmapplans), ancestors, es); break; case T_BitmapOr: ExplainMemberNodes(((BitmapOrState *) planstate)->bitmapplans, ((BitmapOrState *) planstate)->nplans, - list_length(((BitmapOr *) plan)->bitmapplans), ancestors, es); break; case T_SubqueryScan: @@ -3237,32 +3257,33 @@ show_modifytable_info(ModifyTableState *mtstate, List *ancestors, * * The ancestors list should already contain the immediate parent of these * plans. -* -* nsubnodes indicates the number of items in the planstates array. -* nplans indicates the original number of subnodes in the Plan, some of these -* may have been pruned by the run-time pruning code. */ static void -ExplainMemberNodes(PlanState **planstates, int nsubnodes, int nplans, +ExplainMemberNodes(PlanState **planstates, int nplans, List *ancestors, ExplainState *es) { int j; - /* - * The number of subnodes being lower than the number of subplans that was - * specified in the plan means that some subnodes have been ignored per - * instruction for the partition pruning code during the executor - * initialization. To make this a bit less mysterious, we'll indicate - * here that this has happened. - */ - if (nsubnodes < nplans) - ExplainPropertyInteger("Subplans Removed", NULL, nplans - nsubnodes, es); - - for (j = 0; j < nsubnodes; j++) + for (j = 0; j < nplans; j++) ExplainNode(planstates[j], ancestors, "Member", NULL, es); } +/* + * Report about any pruned subnodes of an Append or MergeAppend node. + * + * nplans indicates the number of live subplans. + * nchildren indicates the original number of subnodes in the Plan; + * some of these may have been pruned by the run-time pruning code. + */ +static void +ExplainMissingMembers(int nplans, int nchildren, ExplainState *es) +{ + if (nplans < nchildren || es->format != EXPLAIN_FORMAT_TEXT) + ExplainPropertyInteger("Subplans Removed", NULL, + nchildren - nplans, es); +} + /* * Explain a list of SubPlans (or initPlans, which also use SubPlan nodes). * diff --git a/src/test/regress/expected/partition_prune.out b/src/test/regress/expected/partition_prune.out index 8ae254c673..46a4df8869 100644 --- a/src/test/regress/expected/partition_prune.out +++ b/src/test/regress/expected/partition_prune.out @@ -1887,9 +1887,9 @@ explain (analyze, costs off, summary off, timing off) execute ab_q2 (2, 2); QUERY PLAN -------------------------------------------------------- Append (actual rows=0 loops=1) + Subplans Removed: 6 InitPlan 1 (returns $0) -> Result (actual rows=1 loops=1) - Subplans Removed: 6 -> Seq Scan on ab_a2_b1 (actual rows=0 loops=1) Filter: ((a >= $1) AND (a <= $2) AND (b < $0)) -> Seq Scan on ab_a2_b2 (actual rows=0 loops=1) @@ -1930,9 +1930,9 @@ explain (analyze, costs off, summary off, timing off) execute ab_q3 (2, 2); QUERY PLAN -------------------------------------------------------- Append (actual rows=0 loops=1) + Subplans Removed: 6 InitPlan 1 (returns $0) -> Result (actual rows=1 loops=1) - Subplans Removed: 6 -> Seq Scan on ab_a1_b2 (actual rows=0 loops=1) Filter: ((b >= $1) AND (b <= $2) AND (a < $0)) -> Seq Scan on ab_a2_b2 (actual rows=0 loops=1)