From aaebb7e985935d02f54d46d17c2eaa6610a0eccf Mon Sep 17 00:00:00 2001
From: Jan Vales <jan@jvales.net>
Date: Wed, 3 Apr 2019 03:54:10 +0200
Subject: [PATCH] ex1.4(a) - verbatim copy. TODO: fix overflow.
---
ex1/main_4.tex | 42 +++++++++++++++++++++++++++++++++++++++++-
1 file changed, 41 insertions(+), 1 deletion(-)
diff --git a/ex1/main_4.tex b/ex1/main_4.tex
index 0f21a31..f674397 100644
--- a/ex1/main_4.tex
+++ b/ex1/main_4.tex
@@ -1,9 +1,49 @@
%ex1.4
\begin{enumerate}[label=(\alph*)]
-
\item Hash Join, then Merge Join
+\begin{verbatim}
+Merge Join (cost=126688.84..189746.85 rows=4812309 width=12) (actual time=1235.201..3507.532 rows=4790517 loops=1)
+ Output: r.a, r.b, s.c
+ Merge Cond: ((t.a = r.a) AND (t.c = s.c))
+ Buffers: shared hit=138, temp read=1320 written=3593
+ -> Sort (cost=809.39..834.39 rows=10000 width=8) (actual time=15.180..17.809 rows=10000 loops=1)
+ Output: t.a, t.c
+ Sort Key: t.a, t.c
+ Sort Method: quicksort Memory: 853kB
+ Buffers: shared hit=45
+ -> Seq Scan on public.t (cost=0.00..145.00 rows=10000 width=8) (actual time=0.036..4.271 rows=10000 loops=1)
+ Output: t.a, t.c
+ Buffers: shared hit=45
+ -> Materialize (cost=125878.37..130770.59 rows=978445 width=12) (actual time=1220.009..1810.482 rows=4790518 loops=1)
+ Output: r.a, r.b, s.c
+ Buffers: shared hit=93, temp read=1320 written=3593
+ -> Sort (cost=125878.37..128324.48 rows=978445 width=12) (actual time=1220.003..1267.097 rows=105629 loops=1)
+ Output: r.a, r.b, s.c
+ Sort Key: r.a, s.c
+ Sort Method: external merge Disk: 21312kB
+ Buffers: shared hit=93, temp read=1320 written=3593
+ -> Hash Join (cost=270.00..11799.45 rows=978445 width=12) (actual time=7.133..326.364 rows=993774 loops=1)
+ Output: r.a, r.b, s.c
+ Hash Cond: (r.b = s.b)
+ Buffers: shared hit=93
+ -> Seq Scan on public.r (cost=0.00..145.00 rows=10000 width=8) (actual time=0.023..2.157 rows=10000 loops=1)
+ Output: r.a, r.b
+ Buffers: shared hit=45
+ -> Hash (cost=145.00..145.00 rows=10000 width=8) (actual time=7.022..7.022 rows=10000 loops=1)
+ Output: s.c, s.b
+ Buckets: 16384 Batches: 1 Memory Usage: 519kB
+ Buffers: shared hit=45
+ -> Seq Scan on public.s (cost=0.00..145.00 rows=10000 width=8) (actual time=0.021..3.459 rows=10000 loops=1)
+ Output: s.c, s.b
+ Buffers: shared hit=45
+Planning time: 0.899 ms
+Execution time: 4040.426 ms
+
+\end{verbatim}
+
\item
+
Only Merge join: Total cost: 190481.63
Only Hash join: Total cost: 378418.91
Only Nestloop: Total cost: 174352535.00
--
2.43.0