On 11.01.2025 12:15, Guillaume Lelarge wrote:
Thanks for your patch, this looks like a very interesting feature that
I'd like to see in a future release.
It did a quick run: patch OK, make OK, make install OK, but make check
fails quite a lot on partition_prune.sql.
I guess it would need some work on partition_prune.sql tests and
perhaps also on the docs.
Thanks again.
--
Guillaume.
Yes, certainly. I have fixed partition_prune.sql. In the documentation
example for EXPLAIN ANALYZE where loops is greater than one, I updated
how 'rows' and 'loops' values are displayed so they appear as decimal
fractions with two digits after the decimal point.
I attached fixed patch.
Any suggestions?
--
Best regards,
Ilia Evdokimov,
Tantor Labs LLC.
From a934fbd278350edf7a3a3e7fe620a0027ceb2580 Mon Sep 17 00:00:00 2001
From: Ilia Evdokimov <ilya.evdoki...@tantorlabs.com>
Date: Sat, 11 Jan 2025 13:59:34 +0300
Subject: [PATCH] Clarify display of rows and loops as decimal fractions
When the average number of rows is small compared to the number of loops,
both rows and loops are displayed as decimal fractions with two digits
after the decimal point in EXPLAIN ANALYZE.
---
doc/src/sgml/perform.sgml | 2 +-
src/backend/commands/explain.c | 49 +++++++++++++------
src/test/regress/expected/partition_prune.out | 10 ++--
src/test/regress/sql/partition_prune.sql | 2 +-
4 files changed, 40 insertions(+), 23 deletions(-)
diff --git a/doc/src/sgml/perform.sgml b/doc/src/sgml/perform.sgml
index a502a2aaba..da7a19f4b8 100644
--- a/doc/src/sgml/perform.sgml
+++ b/doc/src/sgml/perform.sgml
@@ -730,7 +730,7 @@ WHERE t1.unique1 < 10 AND t1.unique2 = t2.unique2;
-> Bitmap Index Scan on tenk1_unique1 (cost=0.00..4.36 rows=10 width=0) (actual time=0.004..0.004 rows=10 loops=1)
Index Cond: (unique1 < 10)
Buffers: shared hit=2
- -> Index Scan using tenk2_unique2 on tenk2 t2 (cost=0.29..7.90 rows=1 width=244) (actual time=0.003..0.003 rows=1 loops=10)
+ -> Index Scan using tenk2_unique2 on tenk2 t2 (cost=0.29..7.90 rows=1 width=244) (actual time=0.003..0.003 rows=1.00 loops=10.00)
Index Cond: (unique2 = t1.unique2)
Buffers: shared hit=24 read=6
Planning:
diff --git a/src/backend/commands/explain.c b/src/backend/commands/explain.c
index c24e66f82e..200294b756 100644
--- a/src/backend/commands/explain.c
+++ b/src/backend/commands/explain.c
@@ -1981,14 +1981,14 @@ ExplainNode(PlanState *planstate, List *ancestors,
if (es->format == EXPLAIN_FORMAT_TEXT)
{
+ appendStringInfo(es->str, " (actual");
if (es->timing)
- appendStringInfo(es->str,
- " (actual time=%.3f..%.3f rows=%.0f loops=%.0f)",
- startup_ms, total_ms, rows, nloops);
+ appendStringInfo(es->str, " time=%.3f..%.3f", startup_ms, total_ms);
+
+ if (nloops > 1 && planstate->instrument->ntuples < nloops)
+ appendStringInfo(es->str," rows=%.2f loops=%.2f)", rows, nloops);
else
- appendStringInfo(es->str,
- " (actual rows=%.0f loops=%.0f)",
- rows, nloops);
+ appendStringInfo(es->str," rows=%.0f loops=%.0f)", rows, nloops);
}
else
{
@@ -1999,8 +1999,16 @@ ExplainNode(PlanState *planstate, List *ancestors,
ExplainPropertyFloat("Actual Total Time", "ms", total_ms,
3, es);
}
- ExplainPropertyFloat("Actual Rows", NULL, rows, 0, es);
- ExplainPropertyFloat("Actual Loops", NULL, nloops, 0, es);
+ if (nloops > 1 && planstate->instrument->ntuples < nloops)
+ {
+ ExplainPropertyFloat("Actual Rows", NULL, rows, 2, es);
+ ExplainPropertyFloat("Actual Loops", NULL, nloops, 2, es);
+ }
+ else
+ {
+ ExplainPropertyFloat("Actual Rows", NULL, rows, 0, es);
+ ExplainPropertyFloat("Actual Loops", NULL, nloops, 0, es);
+ }
}
}
else if (es->analyze)
@@ -2052,14 +2060,14 @@ ExplainNode(PlanState *planstate, List *ancestors,
if (es->format == EXPLAIN_FORMAT_TEXT)
{
ExplainIndentText(es);
+ appendStringInfo(es->str, "actual");
if (es->timing)
- appendStringInfo(es->str,
- "actual time=%.3f..%.3f rows=%.0f loops=%.0f\n",
- startup_ms, total_ms, rows, nloops);
+ appendStringInfo(es->str, " time=%.3f..%.3f", startup_ms, total_ms);
+
+ if (nloops > 1 && planstate->instrument->ntuples < nloops)
+ appendStringInfo(es->str," rows=%.2f loops=%.2f)", rows, nloops);
else
- appendStringInfo(es->str,
- "actual rows=%.0f loops=%.0f\n",
- rows, nloops);
+ appendStringInfo(es->str," rows=%.0f loops=%.0f)", rows, nloops);
}
else
{
@@ -2070,8 +2078,17 @@ ExplainNode(PlanState *planstate, List *ancestors,
ExplainPropertyFloat("Actual Total Time", "ms",
total_ms, 3, es);
}
- ExplainPropertyFloat("Actual Rows", NULL, rows, 0, es);
- ExplainPropertyFloat("Actual Loops", NULL, nloops, 0, es);
+
+ if (nloops > 1 && planstate->instrument->ntuples < nloops)
+ {
+ ExplainPropertyFloat("Actual Rows", NULL, rows, 2, es);
+ ExplainPropertyFloat("Actual Loops", NULL, nloops, 2, es);
+ }
+ else
+ {
+ ExplainPropertyFloat("Actual Rows", NULL, rows, 0, es);
+ ExplainPropertyFloat("Actual Loops", NULL, nloops, 0, es);
+ }
}
ExplainCloseWorker(n, es);
diff --git a/src/test/regress/expected/partition_prune.out b/src/test/regress/expected/partition_prune.out
index c52bc40e81..dc6a3cb54a 100644
--- a/src/test/regress/expected/partition_prune.out
+++ b/src/test/regress/expected/partition_prune.out
@@ -2338,7 +2338,7 @@ begin
$1)
loop
ln := regexp_replace(ln, 'Workers Launched: \d+', 'Workers Launched: N');
- ln := regexp_replace(ln, 'actual rows=\d+ loops=\d+', 'actual rows=N loops=N');
+ ln := regexp_replace(ln, 'actual rows=\d+(?:\.\d+)? loops=\d+(?:\.\d+)?', 'actual rows=N loops=N');
ln := regexp_replace(ln, 'Rows Removed by Filter: \d+', 'Rows Removed by Filter: N');
return next ln;
end loop;
@@ -3041,16 +3041,16 @@ select * from tbl1 inner join tprt on tbl1.col1 > tprt.col1;
explain (analyze, costs off, summary off, timing off, buffers off)
select * from tbl1 inner join tprt on tbl1.col1 = tprt.col1;
- QUERY PLAN
---------------------------------------------------------------------------
+ QUERY PLAN
+--------------------------------------------------------------------------------
Nested Loop (actual rows=3 loops=1)
-> Seq Scan on tbl1 (actual rows=5 loops=1)
- -> Append (actual rows=1 loops=5)
+ -> Append (actual rows=0.60 loops=5.00)
-> Index Scan using tprt1_idx on tprt_1 (never executed)
Index Cond: (col1 = tbl1.col1)
-> Index Scan using tprt2_idx on tprt_2 (actual rows=1 loops=2)
Index Cond: (col1 = tbl1.col1)
- -> Index Scan using tprt3_idx on tprt_3 (actual rows=0 loops=3)
+ -> Index Scan using tprt3_idx on tprt_3 (actual rows=0.33 loops=3.00)
Index Cond: (col1 = tbl1.col1)
-> Index Scan using tprt4_idx on tprt_4 (never executed)
Index Cond: (col1 = tbl1.col1)
diff --git a/src/test/regress/sql/partition_prune.sql b/src/test/regress/sql/partition_prune.sql
index d67598d5c7..bb1e09a536 100644
--- a/src/test/regress/sql/partition_prune.sql
+++ b/src/test/regress/sql/partition_prune.sql
@@ -571,7 +571,7 @@ begin
$1)
loop
ln := regexp_replace(ln, 'Workers Launched: \d+', 'Workers Launched: N');
- ln := regexp_replace(ln, 'actual rows=\d+ loops=\d+', 'actual rows=N loops=N');
+ ln := regexp_replace(ln, 'actual rows=\d+(?:\.\d+)? loops=\d+(?:\.\d+)?', 'actual rows=N loops=N');
ln := regexp_replace(ln, 'Rows Removed by Filter: \d+', 'Rows Removed by Filter: N');
return next ln;
end loop;
--
2.34.1
