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RST. DC. R.b. 2 join partitions. ST. S.a. DC. R. RS. R. S. T. T. S. ST. S.b. RS. DC. R.b. T.b. DC. T. S. S.b. S.a. DC. R. R.b. DC. R.a. Joins vs. Plans (Interesting orders). In-memory directory. SELECT R.b FROM R,S,T WHERE R.a = S.a and - PowerPoint PPT Presentation
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SELECT R.bFROM R,S,TWHERE R.a = S.a and S.b = T.b;
SELECT R.bFROM R,S,TWHERE R.a = S.a and S.b = T.bORDER BY R.b ;
Joins vs. Plans (Interesting orders)
T T.bDC
RS S.bDC
DC R.aR
S.aDC S.bS
ST S.aDC
RST DC
In-memory directory
Number of Joins = 4Number of Plans = 1215
R.b
R.b
R.b
R SS T
R ST
RS T
2 join partitions
Order on R.a is interesting (useful) for Merge-join with S
