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Enable futile_union_intersection_subtraction

master
Salvo 'LtWorf' Tomaselli 2020-06-09 11:43:14 +07:00
parent 0dcd639c9d
commit 50647294cb
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1 changed files with 17 additions and 25 deletions
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42
relational/optimizations.py
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@ -125,7 +125,7 @@ def duplicated_select(n: parser.Node) -> Tuple[parser.Node, int]:
return n, changes
def futile_union_intersection_subtraction(n: parser.Node) -> int:
def futile_union_intersection_subtraction(n: parser.Node) -> Tuple[parser.Node, int]:
'''This function locates things like r ᑌ r, and replaces them with r.
R ᑌ R --> R
R ᑎ R --> R
@ -140,47 +140,39 @@ def futile_union_intersection_subtraction(n: parser.Node) -> int:
# Union and intersection of the same thing
if n.name in (UNION, INTERSECTION, JOIN, JOIN_LEFT, JOIN_RIGHT, JOIN_FULL) and n.left == n.right:
changes = 1
replace_node(n, n.left)
return n.left, 1
# selection and union of the same thing
elif (n.name == UNION):
if n.left.name == SELECTION and n.left.child == n.right:
changes = 1
replace_node(n, n.right)
return n.right, 1
elif n.right.name == SELECTION and n.right.child == n.left:
changes = 1
replace_node(n, n.left)
return n.left, 1
# selection and intersection of the same thing
elif n.name == INTERSECTION:
if n.left.name == SELECTION and n.left.child == n.right:
changes = 1
replace_node(n, n.left)
return n.left, 1
elif n.right.name == SELECTION and n.right.child == n.left:
changes = 1
replace_node(n, n.right)
return n.right, 1
# Subtraction and selection of the same thing
elif n.name == DIFFERENCE and \
n.right.name == SELECTION and \
n.right.child == n.left:
n.name = n.right.name
n.kind = n.right.kind
n.child = n.right.child
n.prop = '(not (%s))' % n.right.prop
n.left = n.right = None
return parser.Unary(
SELECTION,
'(not (%s))' % n.right.prop,
n.right.child), 1
# Subtraction of the same thing or with selection on the left child
elif n.name == DIFFERENCE and (n.left == n.right or (n.left.name == SELECTION and n.left.child == n.right)):
changes = 1
n.kind = parser.UNARY
n.name = SELECTION
n.prop = 'False'
n.child = n.left.get_left_leaf()
# n.left=n.right=None
return changes + recoursive_scan(futile_union_intersection_subtraction, n)
return parser.Unary(
SELECTION,
'False',
n.get_left_leaf()
), 1
return n, 0
def down_to_unions_subtractions_intersections(n: parser.Node) -> int:
@ -690,7 +682,7 @@ general_optimizations = [
#selection_inside_projection,
#subsequent_renames,
#swap_rename_select,
#futile_union_intersection_subtraction,
futile_union_intersection_subtraction,
#swap_union_renames,
#swap_rename_projection,
#select_union_intersect_subtract,