c01743aa4 added EXPLAIN output to display the plan node's disabled_node
count whenever that count is above 0. Seemingly, there weren't many
people who liked that output as each parent of a disabled node would
also have a "Disabled Nodes" output due to the way disabled_nodes is
accumulated towards the root plan node. It was often hard and sometimes
impossible to figure out which nodes were disabled from looking at
EXPLAIN. You might think it would be possible to manually add up the
numbers from the "Disabled Nodes" output of a given node's children to
figure out if that node has a higher disabled_nodes count than its
children, but that wouldn't have worked for Append and Merge Append nodes
if some disabled child nodes were run-time pruned during init plan. Those
children are not displayed in EXPLAIN.
Here we attempt to improve this output by only showing "Disabled: true"
against only the nodes which are explicitly disabled themselves. That
seems to be the output that's desired by the most people who voiced
their opinion. This is done by summing up the disabled_nodes of the
given node's children and checking if that number is less than the
disabled_nodes of the current node.
This commit also fixes a bug in make_sort() which was neglecting to set
the Sort's disabled_nodes field. This should have copied what was done
in cost_sort(), but it hadn't been updated. With the new output, the
choice to not maintain that field properly was clearly wrong as the
disabled-ness of the node was attributed to the Sort's parent instead.
Reviewed-by: Laurenz Albe, Alena Rybakina
Discussion: https://postgr.es/m/
9e4ad616bebb103ec2084bf6f724cfc739e7fabb[email protected]
return planstate_tree_walker(planstate, ExplainPreScanNode, rels_used);
}
+/*
+ * plan_is_disabled
+ * Checks if the given plan node type was disabled during query planning.
+ * This is evident by the disable_node field being higher than the sum of
+ * the disabled_node field from the plan's children.
+ */
+static bool
+plan_is_disabled(Plan *plan)
+{
+ int child_disabled_nodes;
+
+ /* The node is certainly not disabled if this is zero */
+ if (plan->disabled_nodes == 0)
+ return false;
+
+ child_disabled_nodes = 0;
+
+ /*
+ * Handle special nodes first. Children of BitmapOrs and BitmapAnds can't
+ * be disabled, so no need to handle those specifically.
+ */
+ if (IsA(plan, Append))
+ {
+ ListCell *lc;
+ Append *aplan = (Append *) plan;
+
+ /*
+ * Sum the Append childrens' disabled_nodes. This purposefully
+ * includes any run-time pruned children. Ignoring those could give
+ * us the incorrect number of disabled nodes.
+ */
+ foreach(lc, aplan->appendplans)
+ {
+ Plan *subplan = lfirst(lc);
+
+ child_disabled_nodes += subplan->disabled_nodes;
+ }
+ }
+ else if (IsA(plan, MergeAppend))
+ {
+ ListCell *lc;
+ MergeAppend *maplan = (MergeAppend *) plan;
+
+ /*
+ * Sum the MergeAppend childrens' disabled_nodes. This purposefully
+ * includes any run-time pruned children. Ignoring those could give
+ * us the incorrect number of disabled nodes.
+ */
+ foreach(lc, maplan->mergeplans)
+ {
+ Plan *subplan = lfirst(lc);
+
+ child_disabled_nodes += subplan->disabled_nodes;
+ }
+ }
+ else if (IsA(plan, SubqueryScan))
+ child_disabled_nodes += ((SubqueryScan *) plan)->subplan->disabled_nodes;
+ else if (IsA(plan, CustomScan))
+ {
+ ListCell *lc;
+ CustomScan *cplan = (CustomScan *) plan;
+
+ foreach(lc, cplan->custom_plans)
+ {
+ Plan *subplan = lfirst(lc);
+
+ child_disabled_nodes += subplan->disabled_nodes;
+ }
+ }
+ else
+ {
+ /*
+ * Else, sum up disabled_nodes from the plan's inner and outer side.
+ */
+ if (outerPlan(plan))
+ child_disabled_nodes += outerPlan(plan)->disabled_nodes;
+ if (innerPlan(plan))
+ child_disabled_nodes += innerPlan(plan)->disabled_nodes;
+ }
+
+ /*
+ * It's disabled if the plan's disable_nodes is higher than the sum of its
+ * child's plan disabled_nodes.
+ */
+ if (plan->disabled_nodes > child_disabled_nodes)
+ return true;
+
+ return false;
+}
+
/*
* ExplainNode -
* Appends a description of a plan tree to es->str
ExplainWorkersState *save_workers_state = es->workers_state;
int save_indent = es->indent;
bool haschildren;
+ bool isdisabled;
/*
* Prepare per-worker output buffers, if needed. We'll append the data in
if (es->format == EXPLAIN_FORMAT_TEXT)
appendStringInfoChar(es->str, '\n');
- if (plan->disabled_nodes != 0)
- ExplainPropertyInteger("Disabled Nodes", NULL, plan->disabled_nodes,
- es);
+
+ isdisabled = plan_is_disabled(plan);
+ if (es->format != EXPLAIN_FORMAT_TEXT || isdisabled)
+ ExplainPropertyBool("Disabled", isdisabled, es);
/* prepare per-worker general execution details */
if (es->workers_state && es->verbose)
plan = &node->plan;
plan->targetlist = lefttree->targetlist;
+ plan->disabled_nodes = lefttree->disabled_nodes + (enable_sort == false);
plan->qual = NIL;
plan->lefttree = lefttree;
plan->righttree = NULL;
QUERY PLAN
-----------------------------------------------------
GroupAggregate
- Disabled Nodes: 2
Group Key: c1.w, c1.z
-> Sort
- Disabled Nodes: 2
Sort Key: c1.w, c1.z, c1.x, c1.y
-> Merge Join
- Disabled Nodes: 2
Merge Cond: (c1.x = c2.x)
-> Sort
Sort Key: c1.x
-> Seq Scan on group_agg_pk c1
- Disabled Nodes: 1
+ Disabled: true
-> Sort
Sort Key: c2.x
-> Seq Scan on group_agg_pk c2
- Disabled Nodes: 1
-(17 rows)
+ Disabled: true
+(14 rows)
SELECT avg(c1.f ORDER BY c1.x, c1.y)
FROM group_agg_pk c1 JOIN group_agg_pk c2 ON c1.x = c2.x
QUERY PLAN
-----------------------------------------------------
Group
- Disabled Nodes: 2
Group Key: c1.x, c1.y
-> Incremental Sort
- Disabled Nodes: 2
Sort Key: c1.x, c1.y
Presorted Key: c1.x
-> Merge Join
- Disabled Nodes: 2
Merge Cond: (c1.x = c2.x)
-> Sort
Sort Key: c1.x
-> Seq Scan on group_agg_pk c1
- Disabled Nodes: 1
+ Disabled: true
-> Sort
Sort Key: c2.x
-> Seq Scan on group_agg_pk c2
- Disabled Nodes: 1
-(18 rows)
+ Disabled: true
+(15 rows)
EXPLAIN (COSTS OFF)
SELECT c1.y,c1.x FROM group_agg_pk c1
QUERY PLAN
-----------------------------------------------------
Group
- Disabled Nodes: 2
Group Key: c2.x, c1.y
-> Incremental Sort
- Disabled Nodes: 2
Sort Key: c2.x, c1.y
Presorted Key: c2.x
-> Merge Join
- Disabled Nodes: 2
Merge Cond: (c1.x = c2.x)
-> Sort
Sort Key: c1.x
-> Seq Scan on group_agg_pk c1
- Disabled Nodes: 1
+ Disabled: true
-> Sort
Sort Key: c2.x
-> Seq Scan on group_agg_pk c2
- Disabled Nodes: 1
-(18 rows)
+ Disabled: true
+(15 rows)
RESET enable_nestloop;
RESET enable_hashjoin;
QUERY PLAN
----------------------------------------------
Sort
- Disabled Nodes: 1
Sort Key: proname
-> Seq Scan on pg_proc
- Disabled Nodes: 1
+ Disabled: true
Filter: (proname ~~* 'ri%foo'::text)
-(6 rows)
+(5 rows)
reset enable_seqscan;
reset enable_indexscan;
QUERY PLAN
-------------------------------
Seq Scan on collate_test1
- Disabled Nodes: 1
+ Disabled: true
Filter: (b ~~* 'abc'::text)
(3 rows)
QUERY PLAN
-------------------------------
Seq Scan on collate_test1
- Disabled Nodes: 1
+ Disabled: true
Filter: (b ~~* 'ABC'::text)
(3 rows)
<Actual-Total-Time>N.N</Actual-Total-Time> +
<Actual-Rows>N</Actual-Rows> +
<Actual-Loops>N</Actual-Loops> +
+ <Disabled>false</Disabled> +
<Shared-Hit-Blocks>N</Shared-Hit-Blocks> +
<Shared-Read-Blocks>N</Shared-Read-Blocks> +
<Shared-Dirtied-Blocks>N</Shared-Dirtied-Blocks>+
Actual Total Time: N.N +
Actual Rows: N +
Actual Loops: N +
+ Disabled: false +
Shared Hit Blocks: N +
Shared Read Blocks: N +
Shared Dirtied Blocks: N +
"Total Cost": N.N, +
"Plan Rows": N, +
"Plan Width": N, +
+ "Disabled": false, +
"Shared Hit Blocks": N, +
"Shared Read Blocks": N, +
"Shared Dirtied Blocks": N, +
"Actual Total Time": N.N, +
"Actual Rows": N, +
"Actual Loops": N, +
+ "Disabled": false, +
"Shared Hit Blocks": N, +
"Shared Read Blocks": N, +
"Shared Dirtied Blocks": N, +
Total Cost: N.N +
Plan Rows: N +
Plan Width: N +
+ Disabled: false +
Planning: +
Memory Used: N +
Memory Allocated: N +
"Actual Startup Time": N.N, +
"Actual Total Time": N.N, +
"Actual Rows": N, +
- "Actual Loops": N +
+ "Actual Loops": N, +
+ "Disabled": false +
}, +
"Planning": { +
"Memory Used": N, +
"string4" +
], +
"Schema": "public", +
+ "Disabled": false, +
"Node Type": "Seq Scan", +
"Plan Rows": 0, +
"Plan Width": 0, +
"stringu2", +
"string4" +
], +
+ "Disabled": false, +
"Sort Key": [ +
"tenk1.tenthous" +
], +
"stringu2", +
"string4" +
], +
+ "Disabled": false, +
"Node Type": "Gather Merge", +
"Plan Rows": 0, +
"Plan Width": 0, +
-------------------------------------------------
[ +
{ +
+ "Disabled": false, +
"Sort Key": [ +
"t.a", +
"t.b" +
QUERY PLAN
------------------------------------------------
Nested Loop Left Join
- Disabled Nodes: 1
Join Filter: (t_1.a = t.a)
-> Seq Scan on t
Filter: (a = ANY ('{1,2}'::integer[]))
-> Incremental Sort
- Disabled Nodes: 1
Sort Key: t_1.a, t_1.b
Presorted Key: t_1.a
-> Sort
- Disabled Nodes: 1
+ Disabled: true
Sort Key: t_1.a
-> Seq Scan on t t_1
-(13 rows)
+(11 rows)
select * from t left join (select * from (select * from t order by a) v order by a, b) s on s.a = t.a where t.a in (1, 2);
a | b | a | b
-------------------------------------------------
[ +
{ +
+ "Disabled": false, +
"Sort Key": [ +
"t.a", +
"t.b" +
QUERY PLAN
------------------------------------------------------------------------
Merge Append
- Disabled Nodes: 1
Sort Key: ((1 - matest0.id))
-> Index Scan using matest0i on public.matest0 matest0_1
Output: matest0_1.id, matest0_1.name, (1 - matest0_1.id)
Output: matest0_3.id, matest0_3.name, ((1 - matest0_3.id))
Sort Key: ((1 - matest0_3.id))
-> Seq Scan on public.matest2 matest0_3
- Disabled Nodes: 1
+ Disabled: true
Output: matest0_3.id, matest0_3.name, (1 - matest0_3.id)
-> Index Scan using matest3i on public.matest3 matest0_4
Output: matest0_4.id, matest0_4.name, (1 - matest0_4.id)
-(15 rows)
+(14 rows)
select * from matest0 order by 1-id;
id | name
"Async Capable": false, +
"Relation Name": "insertconflicttest", +
"Alias": "insertconflicttest", +
+ "Disabled": false, +
"Conflict Resolution": "UPDATE", +
"Conflict Arbiter Indexes": ["key_index"], +
"Conflict Filter": "(insertconflicttest.fruit <> 'Lime'::text)",+
"Node Type": "Result", +
"Parent Relationship": "Outer", +
"Parallel Aware": false, +
- "Async Capable": false +
+ "Async Capable": false, +
+ "Disabled": false +
} +
] +
} +
QUERY PLAN
---------------------------------------------------------
Nested Loop Anti Join
- Disabled Nodes: 1
-> Seq Scan on skip_fetch t1
- Disabled Nodes: 1
+ Disabled: true
-> Materialize
-> Bitmap Heap Scan on skip_fetch t2
Recheck Cond: (a = 1)
-> Bitmap Index Scan on skip_fetch_a_idx
Index Cond: (a = 1)
-(9 rows)
+(8 rows)
SELECT t1.a FROM skip_fetch t1 LEFT JOIN skip_fetch t2 ON t2.a = 1 WHERE t2.a IS NULL;
a
explain_memoize
----------------------------------------------------------------------------------
Nested Loop (actual rows=24 loops=N)
- Disabled Nodes: 1
-> Seq Scan on strtest s1 (actual rows=6 loops=N)
- Disabled Nodes: 1
+ Disabled: true
-> Memoize (actual rows=4 loops=N)
Cache Key: s1.n
Cache Mode: binary
Hits: 3 Misses: 3 Evictions: Zero Overflows: 0 Memory Usage: NkB
-> Index Scan using strtest_n_idx on strtest s2 (actual rows=4 loops=N)
Index Cond: (n <= s1.n)
-(10 rows)
+(9 rows)
-- Ensure we get 3 hits and 3 misses
SELECT explain_memoize('
explain_memoize
----------------------------------------------------------------------------------
Nested Loop (actual rows=24 loops=N)
- Disabled Nodes: 1
-> Seq Scan on strtest s1 (actual rows=6 loops=N)
- Disabled Nodes: 1
+ Disabled: true
-> Memoize (actual rows=4 loops=N)
Cache Key: s1.t
Cache Mode: binary
Hits: 3 Misses: 3 Evictions: Zero Overflows: 0 Memory Usage: NkB
-> Index Scan using strtest_t_idx on strtest s2 (actual rows=4 loops=N)
Index Cond: (t <= s1.t)
-(10 rows)
+(9 rows)
DROP TABLE strtest;
-- Ensure memoize works with partitionwise join
QUERY PLAN
------------------------------------------------------------
Aggregate
- Disabled Nodes: 1
-> Nested Loop
- Disabled Nodes: 1
-> Gather
- Disabled Nodes: 1
Workers Planned: 4
-> Parallel Seq Scan on tenk2
- Disabled Nodes: 1
+ Disabled: true
Filter: (thousand = 0)
-> Gather
Workers Planned: 4
Recheck Cond: (hundred > 1)
-> Bitmap Index Scan on tenk1_hundred
Index Cond: (hundred > 1)
-(16 rows)
+(13 rows)
select count(*) from tenk1, tenk2 where tenk1.hundred > 1 and tenk2.thousand=0;
count
"Async Capable": false, +
"Table Function Name": "json_table", +
"Alias": "json_table_func", +
+ "Disabled": false, +
"Output": ["id", "\"int\"", "text"], +
"Table Function Call": "JSON_TABLE('null'::jsonb, '$[*]' AS json_table_path_0 PASSING 3 AS a, '\"foo\"'::jsonb AS \"b c\" COLUMNS (id FOR ORDINALITY, \"int\" integer PATH '$', text text PATH '$'))"+
} +
QUERY PLAN
---------------------------
HashAggregate
- Disabled Nodes: 1
+ Disabled: true
Group Key: ('123'::xid)
-> Append
-> Result
"Parallel Aware": false, +
"Async Capable": false, +
"Join Type": "Inner", +
+ "Disabled": false, +
"Output": ["f.\"COUNTRY_NAME\"", "f.\"REGION_ID\""], +
"Inner Unique": false, +
"Plans": [ +
"Relation Name": "xmldata", +
"Schema": "public", +
"Alias": "xmldata", +
+ "Disabled": false, +
"Output": ["xmldata.data"] +
}, +
{ +
"Async Capable": false, +
"Table Function Name": "xmltable", +
"Alias": "f", +
+ "Disabled": false, +
"Output": ["f.\"COUNTRY_NAME\"", "f.\"REGION_ID\""], +
"Table Function Call": "XMLTABLE(('/ROWS/ROW[COUNTRY_NAME=\"Japan\" or COUNTRY_NAME=\"India\"]'::text) PASSING (xmldata.data) COLUMNS \"COUNTRY_NAME\" text, \"REGION_ID\" integer)",+
"Filter": "(f.\"COUNTRY_NAME\" = 'Japan'::text)" +
"Parallel Aware": false, +
"Async Capable": false, +
"Join Type": "Inner", +
+ "Disabled": false, +
"Output": ["f.\"COUNTRY_NAME\"", "f.\"REGION_ID\""], +
"Inner Unique": false, +
"Plans": [ +
"Relation Name": "xmldata", +
"Schema": "public", +
"Alias": "xmldata", +
+ "Disabled": false, +
"Output": ["xmldata.data"] +
}, +
{ +
"Async Capable": false, +
"Table Function Name": "xmltable", +
"Alias": "f", +
+ "Disabled": false, +
"Output": ["f.\"COUNTRY_NAME\"", "f.\"REGION_ID\""], +
"Table Function Call": "XMLTABLE(('/ROWS/ROW[COUNTRY_NAME=\"Japan\" or COUNTRY_NAME=\"India\"]'::text) PASSING (xmldata.data) COLUMNS \"COUNTRY_NAME\" text, \"REGION_ID\" integer)",+
"Filter": "(f.\"COUNTRY_NAME\" = 'Japan'::text)" +
"Parallel Aware": false, +
"Async Capable": false, +
"Join Type": "Inner", +
+ "Disabled": false, +
"Output": ["f.\"COUNTRY_NAME\"", "f.\"REGION_ID\""], +
"Inner Unique": false, +
"Plans": [ +
"Relation Name": "xmldata", +
"Schema": "public", +
"Alias": "xmldata", +
+ "Disabled": false, +
"Output": ["xmldata.data"] +
}, +
{ +
"Async Capable": false, +
"Table Function Name": "xmltable", +
"Alias": "f", +
+ "Disabled": false, +
"Output": ["f.\"COUNTRY_NAME\"", "f.\"REGION_ID\""], +
"Table Function Call": "XMLTABLE(('/ROWS/ROW[COUNTRY_NAME=\"Japan\" or COUNTRY_NAME=\"India\"]'::text) PASSING (xmldata.data) COLUMNS \"COUNTRY_NAME\" text, \"REGION_ID\" integer)",+
"Filter": "(f.\"COUNTRY_NAME\" = 'Japan'::text)" +
projects / postgresql.git / commitdiff