Skip to content

Commit d22782a

Browse files
tvondratvondra
committed
Minor improvements in Incremental Sort explain
Some places still used "Maximum" instead of "Peak" when displaying info about sort space, so fix that. Also, add a comment clarifying why it's correct to check the number of full/prefix sort groups. Author: James Coleman Discussion: https://postgr.es/m/CAPpHfds1waRZ=NOmueYq0sx1ZSCnt+5QJvizT8ndT2=etZEeAQ@mail.gmail.com
1 parent 4bd0ad9 commit d22782a

File tree

3 files changed

+87
-71
lines changed

3 files changed

+87
-71
lines changed

‎src/backend/commands/explain.c‎

Lines changed: 18 additions & 2 deletions
Original file line numberDiff line numberDiff line change
@@ -2841,7 +2841,7 @@ show_incremental_sort_group_info(IncrementalSortGroupInfo *groupInfo,
28412841
ExplainOpenGroup("Sort Space", memoryName.data, true, es);
28422842

28432843
ExplainPropertyInteger("Average Sort Space Used", "kB", avgSpace, es);
2844-
ExplainPropertyInteger("Maximum Sort Space Used", "kB",
2844+
ExplainPropertyInteger("Peak Sort Space Used", "kB",
28452845
groupInfo->maxMemorySpaceUsed, es);
28462846

28472847
ExplainCloseGroup("Sort Spaces", memoryName.data, true, es);
@@ -2858,7 +2858,7 @@ show_incremental_sort_group_info(IncrementalSortGroupInfo *groupInfo,
28582858
ExplainOpenGroup("Sort Space", diskName.data, true, es);
28592859

28602860
ExplainPropertyInteger("Average Sort Space Used", "kB", avgSpace, es);
2861-
ExplainPropertyInteger("Maximum Sort Space Used", "kB",
2861+
ExplainPropertyInteger("Peak Sort Space Used", "kB",
28622862
groupInfo->maxDiskSpaceUsed, es);
28632863

28642864
ExplainCloseGroup("Sort Spaces", diskName.data, true, es);
@@ -2883,6 +2883,15 @@ show_incremental_sort_info(IncrementalSortState *incrsortstate,
28832883
if (!es->analyze)
28842884
return;
28852885

2886+
/*
2887+
* Since we never have any prefix groups unless we've first sorted a full
2888+
* groups and transitioned modes (copying the tuples into a prefix group),
2889+
* we don't need to do anything if there were 0 full groups.
2890+
*
2891+
* We still have to continue after this block if there are no full groups,
2892+
* though, since it's possible that we have workers that did real work even
2893+
* if the leader didn't participate.
2894+
*/
28862895
if (fullsortGroupInfo->groupCount > 0)
28872896
{
28882897
show_incremental_sort_group_info(fullsortGroupInfo, "Full-sort", true, es);
@@ -2914,6 +2923,13 @@ show_incremental_sort_info(IncrementalSortState *incrsortstate,
29142923
*/
29152924
fullsortGroupInfo = &incsort_info->fullsortGroupInfo;
29162925
prefixsortGroupInfo = &incsort_info->prefixsortGroupInfo;
2926+
2927+
/*
2928+
* Since we never have any prefix groups unless we've first sorted
2929+
* a full groups and transitioned modes (copying the tuples into a
2930+
* prefix group), we don't need to do anything if there were 0 full
2931+
* groups.
2932+
*/
29172933
if (fullsortGroupInfo->groupCount == 0 &&
29182934
prefixsortGroupInfo->groupCount == 0)
29192935
continue;

‎src/test/regress/expected/incremental_sort.out‎

Lines changed: 67 additions & 67 deletions
Original file line numberDiff line numberDiff line change
@@ -109,7 +109,7 @@ begin
109109
for group_key in select unnest(array['Full-sort Groups', 'Presorted Groups']::text[]) t loop
110110
for space_key in select unnest(array['Sort Space Memory', 'Sort Space Disk']::text[]) t loop
111111
node := jsonb_set(node, array[group_key, space_key, 'Average Sort Space Used'], '"NN"', false);
112-
node := jsonb_set(node, array[group_key, space_key, 'Maximum Sort Space Used'], '"NN"', false);
112+
node := jsonb_set(node, array[group_key, space_key, 'Peak Sort Space Used'], '"NN"', false);
113113
end loop;
114114
end loop;
115115
nodes := nodes || node;
@@ -131,7 +131,7 @@ begin
131131
for group_key in select unnest(array['Full-sort Groups', 'Presorted Groups']::text[]) t loop
132132
group_stats := node->group_key;
133133
for space_key in select unnest(array['Sort Space Memory', 'Sort Space Disk']::text[]) t loop
134-
if (group_stats->space_key->'Maximum Sort Space Used')::bigint < (group_stats->space_key->'Maximum Sort Space Used')::bigint then
134+
if (group_stats->space_key->'Peak Sort Space Used')::bigint < (group_stats->space_key->'Peak Sort Space Used')::bigint then
135135
raise exception '% has invalid max space < average space', group_key;
136136
end if;
137137
end loop;
@@ -545,34 +545,34 @@ select explain_analyze_without_memory('select * from (select * from t order by a
545545
(9 rows)
546546

547547
select jsonb_pretty(explain_analyze_inc_sort_nodes_without_memory('select * from (select * from t order by a) s order by a, b limit 55'));
548-
jsonb_pretty
549-
--------------------------------------------------
550-
[ +
551-
{ +
552-
"Sort Key": [ +
553-
"t.a", +
554-
"t.b" +
555-
], +
556-
"Node Type": "Incremental Sort", +
557-
"Actual Rows": 55, +
558-
"Actual Loops": 1, +
559-
"Presorted Key": [ +
560-
"t.a" +
561-
], +
562-
"Parallel Aware": false, +
563-
"Full-sort Groups": { +
564-
"Group Count": 2, +
565-
"Sort Methods Used": [ +
566-
"top-N heapsort", +
567-
"quicksort" +
568-
], +
569-
"Sort Space Memory": { +
570-
"Average Sort Space Used": "NN",+
571-
"Maximum Sort Space Used": "NN" +
572-
} +
573-
}, +
574-
"Parent Relationship": "Outer" +
575-
} +
548+
jsonb_pretty
549+
-------------------------------------------------
550+
[ +
551+
{ +
552+
"Sort Key": [ +
553+
"t.a", +
554+
"t.b" +
555+
], +
556+
"Node Type": "Incremental Sort", +
557+
"Actual Rows": 55, +
558+
"Actual Loops": 1, +
559+
"Presorted Key": [ +
560+
"t.a" +
561+
], +
562+
"Parallel Aware": false, +
563+
"Full-sort Groups": { +
564+
"Group Count": 2, +
565+
"Sort Methods Used": [ +
566+
"top-N heapsort", +
567+
"quicksort" +
568+
], +
569+
"Sort Space Memory": { +
570+
"Peak Sort Space Used": "NN", +
571+
"Average Sort Space Used": "NN"+
572+
} +
573+
}, +
574+
"Parent Relationship": "Outer" +
575+
} +
576576
]
577577
(1 row)
578578

@@ -719,43 +719,43 @@ select explain_analyze_without_memory('select * from (select * from t order by a
719719
(9 rows)
720720

721721
select jsonb_pretty(explain_analyze_inc_sort_nodes_without_memory('select * from (select * from t order by a) s order by a, b limit 70'));
722-
jsonb_pretty
723-
--------------------------------------------------
724-
[ +
725-
{ +
726-
"Sort Key": [ +
727-
"t.a", +
728-
"t.b" +
729-
], +
730-
"Node Type": "Incremental Sort", +
731-
"Actual Rows": 70, +
732-
"Actual Loops": 1, +
733-
"Presorted Key": [ +
734-
"t.a" +
735-
], +
736-
"Parallel Aware": false, +
737-
"Full-sort Groups": { +
738-
"Group Count": 1, +
739-
"Sort Methods Used": [ +
740-
"quicksort" +
741-
], +
742-
"Sort Space Memory": { +
743-
"Average Sort Space Used": "NN",+
744-
"Maximum Sort Space Used": "NN" +
745-
} +
746-
}, +
747-
"Presorted Groups": { +
748-
"Group Count": 5, +
749-
"Sort Methods Used": [ +
750-
"quicksort" +
751-
], +
752-
"Sort Space Memory": { +
753-
"Average Sort Space Used": "NN",+
754-
"Maximum Sort Space Used": "NN" +
755-
} +
756-
}, +
757-
"Parent Relationship": "Outer" +
758-
} +
722+
jsonb_pretty
723+
-------------------------------------------------
724+
[ +
725+
{ +
726+
"Sort Key": [ +
727+
"t.a", +
728+
"t.b" +
729+
], +
730+
"Node Type": "Incremental Sort", +
731+
"Actual Rows": 70, +
732+
"Actual Loops": 1, +
733+
"Presorted Key": [ +
734+
"t.a" +
735+
], +
736+
"Parallel Aware": false, +
737+
"Full-sort Groups": { +
738+
"Group Count": 1, +
739+
"Sort Methods Used": [ +
740+
"quicksort" +
741+
], +
742+
"Sort Space Memory": { +
743+
"Peak Sort Space Used": "NN", +
744+
"Average Sort Space Used": "NN"+
745+
} +
746+
}, +
747+
"Presorted Groups": { +
748+
"Group Count": 5, +
749+
"Sort Methods Used": [ +
750+
"quicksort" +
751+
], +
752+
"Sort Space Memory": { +
753+
"Peak Sort Space Used": "NN", +
754+
"Average Sort Space Used": "NN"+
755+
} +
756+
}, +
757+
"Parent Relationship": "Outer" +
758+
} +
759759
]
760760
(1 row)
761761

‎src/test/regress/sql/incremental_sort.sql‎

Lines changed: 2 additions & 2 deletions
Original file line numberDiff line numberDiff line change
@@ -85,7 +85,7 @@ begin
8585
for group_key in select unnest(array['Full-sort Groups', 'Presorted Groups']::text[]) t loop
8686
for space_key in select unnest(array['Sort Space Memory', 'Sort Space Disk']::text[]) t loop
8787
node := jsonb_set(node, array[group_key, space_key, 'Average Sort Space Used'], '"NN"', false);
88-
node := jsonb_set(node, array[group_key, space_key, 'Maximum Sort Space Used'], '"NN"', false);
88+
node := jsonb_set(node, array[group_key, space_key, 'Peak Sort Space Used'], '"NN"', false);
8989
end loop;
9090
end loop;
9191
nodes := nodes || node;
@@ -108,7 +108,7 @@ begin
108108
for group_key in select unnest(array['Full-sort Groups', 'Presorted Groups']::text[]) t loop
109109
group_stats := node->group_key;
110110
for space_key in select unnest(array['Sort Space Memory', 'Sort Space Disk']::text[]) t loop
111-
if (group_stats->space_key->'Maximum Sort Space Used')::bigint < (group_stats->space_key->'Maximum Sort Space Used')::bigint then
111+
if (group_stats->space_key->'Peak Sort Space Used')::bigint < (group_stats->space_key->'Peak Sort Space Used')::bigint then
112112
raise exception '% has invalid max space < average space', group_key;
113113
end if;
114114
end loop;

0 commit comments

Comments
 (0)