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Pig >> mail # user >> LEFT OUTER JOIN?


Consider two aliases (T) and (U), loaded from data with schema defined
below. I was considering a left outer join to 'merge' the two records,
overriding those in U with the join fields in T, but the result isn't what
I desired.  Possibly a filter then union is required? I'm just not sure;
looking for a quick way to get to this result (R):

R: ?[JOIN T BY (a,b,c,d) LEFT OUTER, U BY (a,b,c,d)]: schema : a,b,c,d,x,y
a1 b1 c1 d1 *g1 h1*
a2 b2 c2 d2 e2 f2
a3 b3 c3 d3 *g3 h3*
a4 b4 c4 d4 e4 f4
a5 b5 c5 d5 e5 f5
a6 b6 c6 d6 g6 h6

T : schema : a,b,c,d,x,y
a1 b1 c1 d1 g1 h1
a3 b3 c3 d3 g3 h3
a6 b6 c6 d6 g6 h6

U: schema : a,b,c,d,x,y
a1 b1 c1 d1 e1 f1
a2 b2 c2 d2 e2 f2
a3 b3 c3 d3 e3 f3
a4 b4 c4 d4 e4 f4
a5 b5 c5 d5 e5 f5

Many thanks,  -Dan
+
Dan DeCapria, CivicScienc... 2013-04-19, 21:10