def create_index(self, column_number):
if column_number in self.col_btree:
return
print("Create index", column_number)
zeros = [None] * self.table.num_columns
mask = Bits("")
mask.build_from_list(zeros[:column_number] + [1] +
zeros[column_number:])
tree = OOBTreePy()
ks = {}
for rid in self.table.page_directory:
_m = self.table.page_directory[rid]
if _m.indirection == 0 or _m.indirection > rid:
#print("ADDING INDEX:",rid)
r = self.table.get(rid, mask)
#ks[rid] = r.columns[0]
ks[r[0]] = [rid]
tree.update(ks)
self.col_btree[column_number] = tree
return True
class Index:
def __init__(self, table):
self.tree = None
"""
# returns the location of all records with the given value
"""
def locate(self, value):
return self.tree.values(value)
"""
# optional: Create index on specific column
"""
def create_index(self, table, column_number):
zeros = [None] * table.num_columns
mask = Bits("")
mask.build_from_list(zeros[:column_number] + [1] +
zeros[column_number:])
self.tree = OOBTreePy()
ks = {}
for rid in table.page_directory:
r = table.get(rid, mask)
ks[rid] = r.columns[0]
self.tree.update(ks)
"""
# optional: Drop index of specific column
"""
def drop_index(self, table, column_number):
self.tree = None
def get_range(self, l, r):
return self.tree.values(min=l, max=r)