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Improve EXPLAIN to print the grouping columns in Agg and Group nodes.

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Per request from Kevin Grittner.
This commit is contained in:
Tom Lane
2013-12-12 11:24:38 -05:00
parent 8693559cac
commit f26099057a
6 changed files with 92 additions and 30 deletions
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77
src/backend/commands/explain.c
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@ -76,9 +76,13 @@ static void show_sort_keys(SortState *sortstate, List *ancestors,
ExplainState *es);
static void show_merge_append_keys(MergeAppendState *mstate, List *ancestors,
ExplainState *es);
static void show_sort_keys_common(PlanState *planstate,
int nkeys, AttrNumber *keycols,
List *ancestors, ExplainState *es);
static void show_agg_keys(AggState *astate, List *ancestors,
ExplainState *es);
static void show_group_keys(GroupState *gstate, List *ancestors,
ExplainState *es);
static void show_sort_group_keys(PlanState *planstate, const char *qlabel,
int nkeys, AttrNumber *keycols,
List *ancestors, ExplainState *es);
static void show_sort_info(SortState *sortstate, ExplainState *es);
static void show_hash_info(HashState *hashstate, ExplainState *es);
static void show_instrumentation_count(const char *qlabel, int which,
@ -1341,7 +1345,14 @@ ExplainNode(PlanState *planstate, List *ancestors,
planstate, es);
break;
case T_Agg:
show_agg_keys((AggState *) planstate, ancestors, es);
show_upper_qual(plan->qual, "Filter", planstate, ancestors, es);
if (plan->qual)
show_instrumentation_count("Rows Removed by Filter", 1,
planstate, es);
break;
case T_Group:
show_group_keys((GroupState *) planstate, ancestors, es);
show_upper_qual(plan->qual, "Filter", planstate, ancestors, es);
if (plan->qual)
show_instrumentation_count("Rows Removed by Filter", 1,
@ -1693,9 +1704,9 @@ show_sort_keys(SortState *sortstate, List *ancestors, ExplainState *es)
{
Sort *plan = (Sort *) sortstate->ss.ps.plan;
show_sort_keys_common((PlanState *) sortstate,
plan->numCols, plan->sortColIdx,
ancestors, es);
show_sort_group_keys((PlanState *) sortstate, "Sort Key",
plan->numCols, plan->sortColIdx,
ancestors, es);
}
/*
@ -1707,14 +1718,56 @@ show_merge_append_keys(MergeAppendState *mstate, List *ancestors,
{
MergeAppend *plan = (MergeAppend *) mstate->ps.plan;
show_sort_keys_common((PlanState *) mstate,
plan->numCols, plan->sortColIdx,
ancestors, es);
show_sort_group_keys((PlanState *) mstate, "Sort Key",
plan->numCols, plan->sortColIdx,
ancestors, es);
}
/*
* Show the grouping keys for an Agg node.
*/
static void
show_sort_keys_common(PlanState *planstate, int nkeys, AttrNumber *keycols,
List *ancestors, ExplainState *es)
show_agg_keys(AggState *astate, List *ancestors,
ExplainState *es)
{
Agg *plan = (Agg *) astate->ss.ps.plan;
if (plan->numCols > 0)
{
/* The key columns refer to the tlist of the child plan */
ancestors = lcons(astate, ancestors);
show_sort_group_keys(outerPlanState(astate), "Group Key",
plan->numCols, plan->grpColIdx,
ancestors, es);
ancestors = list_delete_first(ancestors);
}
}
/*
* Show the grouping keys for a Group node.
*/
static void
show_group_keys(GroupState *gstate, List *ancestors,
ExplainState *es)
{
Group *plan = (Group *) gstate->ss.ps.plan;
/* The key columns refer to the tlist of the child plan */
ancestors = lcons(gstate, ancestors);
show_sort_group_keys(outerPlanState(gstate), "Group Key",
plan->numCols, plan->grpColIdx,
ancestors, es);
ancestors = list_delete_first(ancestors);
}
/*
* Common code to show sort/group keys, which are represented in plan nodes
* as arrays of targetlist indexes
*/
static void
show_sort_group_keys(PlanState *planstate, const char *qlabel,
int nkeys, AttrNumber *keycols,
List *ancestors, ExplainState *es)
{
Plan *plan = planstate->plan;
List *context;
@ -1748,7 +1801,7 @@ show_sort_keys_common(PlanState *planstate, int nkeys, AttrNumber *keycols,
result = lappend(result, exprstr);
}
ExplainPropertyList("Sort Key", result, es);
ExplainPropertyList(qlabel, result, es);
}
/*