CCF_100
/
relational
1
0
Fork 0
Code Issues Pull Requests Releases Wiki Activity
relational/tests_dir/union_projection.query

2 lines
103 B
Plaintext
Raw Normal View History Unescape Escape

New optimization Turns π a,b,c(A) ∪ π a,b,c(B) into π a,b,c(A ∪ B) if A and B are union compatible Works with union, intersection and difference.
2016-01-03 03:07:23 +07:00
πname,skill(σ skill == 'Perl' (people⋈skills)) ∪ πname,skill(σ skill == 'C' (people⋈skills))