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relational
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Removed redundant check 

Assuming that the query is correct, the removed condition must
always be true.
master
Salvo 'LtWorf' Tomaselli 2016-01-03 12:36:39 +07:00
parent 3b3888e9be
commit d384a902cf
1 changed files with 0 additions and 2 deletions
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relational/optimizations.py
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@ -558,7 +558,6 @@ def projection_and_union(n, rels):
if n.name in {UNION, INTERSECTION, DIFFERENCE} and \
n.left.name == PROJECTION and \
n.right.name == PROJECTION and \
set(n.left.result_format(rels)) == set(n.right.result_format(rels)) and \
set(n.left.child.result_format(rels)) == set(n.right.child.result_format(rels)):
newchild = parser.Node()
@ -577,7 +576,6 @@ def projection_and_union(n, rels):
return changes + recoursive_scan(projection_and_union, n, rels)
def selection_and_product(n, rels):
'''This function locates things like σ k (R*Q) and converts them into
σ l (σ j (R) * σ i (Q)). Where j contains only attributes belonging to R,