2martens/uni
1
0
Fork 0
mirror of https://github.com/2martens/uni.git synced 2026-05-06 11:26:25 +02:00
Code Releases Activity

GDB-4: Aufgabe 4 korrigiert.

Browse Source
This commit is contained in:
Jim Martens
2013-12-12 15:34:07 +01:00
parent 9913b6fc95
commit 3b2a28a11d
1 changed files with 10 additions and 8 deletions
Download Patch File Download Diff File Expand all files Collapse all files

18
gdb/G62B4_Dittrich-Lindemann-Martens.tex
View File

@ -173,14 +173,16 @@
anfänglicher Operatorbaum:\\
\begin{tikzpicture}[shorten >=1pt,node distance=1.1cm,on grid]
\node (proj) {$\pi_{Person.PNR, Person.Vorname, Person.Nachname}$};
\node (sel) [below=2.0 of proj] {$\sigma_{Obst.Sorte\text{ LIKE 'K\%'}}$};
\node (join) [below=2.0 of sel] {$\underset{Person.Lieblingsobst = Obst.ONR}{\bowtie}$};
\node (person) [below left=2.0 and 2.0 of join] {Person};
\node (obst) [below right=2.0 and 2.0 of join] {Obst};
\node (sel) [below=2.0 of proj] {$\sigma_{Obst.Sorte\text{ LIKE 'K\%'}}$};
\node (sel2) [below=2.0 of sel] {$\sigma_{Obst.ONR=Person.Lieblingsobst}$};
\node (catProd) [below=2.0 of sel2] {x};
\node (person) [below left=2.0 and 2.0 of catProd] {Person};
\node (obst) [below right=2.0 and 2.0 of catProd] {Obst};
\path (proj) edge node [right] {400} (sel)
(sel) edge node [right] {2000} (join)
(join) edge node [left] {2000} (person)
(join) edge node [right] {25} (obst);
(sel) edge node [right] {2000} (sel2)
(sel2) edge node [right] {50000} (catProd)
(catProd) edge node [left] {2000} (person)
(catProd) edge node [right] {25} (obst);
\end{tikzpicture}
optimierter Operatorbaum:\\
@ -196,5 +198,5 @@
(sel) edge node [right] {25} (obst);
\end{tikzpicture}
Der zweite Operatorbaum ist klar performanter, da die Selektion der Obstsorte bereits vor dem Join stattfindet.
Der zweite Operatorbaum ist klar performanter, da die Selektion der Obstsorte bereits vor dem Join stattfindet und das kartesische Produkt und die zweite Selektion zu einem Join verbunden wurde.
\end{document}